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Showing 1 - 200 of 1566 Journals sorted alphabetically
4OR: A Quarterly Journal of Operations Research     Hybrid Journal   (Followers: 10)
Abacus     Hybrid Journal   (Followers: 13)
Accounting Forum     Hybrid Journal   (Followers: 25)
Acta Amazonica     Open Access   (Followers: 5)
Acta Commercii     Open Access   (Followers: 4)
Acta Oeconomica     Full-text available via subscription   (Followers: 3)
Acta Scientiarum. Human and Social Sciences     Open Access   (Followers: 8)
Acta Universitatis Danubius. Œconomica     Open Access   (Followers: 3)
Acta Universitatis Nicolai Copernici Zarządzanie     Open Access   (Followers: 4)
AD-minister     Open Access   (Followers: 3)
Adam Academy : Journal of Social Sciences / Adam Akademi : Sosyal Bilimler Dergisi     Open Access  
Admisi dan Bisnis     Open Access  
ADR Bulletin     Open Access   (Followers: 5)
Advances in Developing Human Resources     Hybrid Journal   (Followers: 24)
Advances in Economics and Business     Open Access   (Followers: 13)
AfricaGrowth Agenda     Full-text available via subscription   (Followers: 1)
African Affairs     Hybrid Journal   (Followers: 63)
African Development Review     Hybrid Journal   (Followers: 36)
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African Journal of Business Ethics     Open Access   (Followers: 6)
African Review of Economics and Finance     Open Access   (Followers: 3)
Afro-Asian Journal of Finance and Accounting     Hybrid Journal   (Followers: 7)
Afyon Kocatepe Üniversitesi İktisadi ve İdari Bilimler Fakültesi Dergisi     Open Access   (Followers: 3)
Agronomy     Open Access   (Followers: 10)
Akademik Yaklaşımlar Dergisi     Open Access  
Akademika : Journal of Southeast Asia Social Sciences and Humanities     Open Access   (Followers: 7)
Alphanumeric Journal : The Journal of Operations Research, Statistics, Econometrics and Management Information Systems     Open Access   (Followers: 5)
American Economic Journal : Applied Economics     Full-text available via subscription   (Followers: 182)
American Enterprise Institute     Free  
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American Journal of Business Education     Open Access   (Followers: 12)
American Journal of Economics and Business Administration     Open Access   (Followers: 26)
American Journal of Economics and Sociology     Hybrid Journal   (Followers: 31)
American Journal of Evaluation     Hybrid Journal   (Followers: 14)
American Journal of Finance and Accounting     Hybrid Journal   (Followers: 21)
American Journal of Health Economics     Full-text available via subscription   (Followers: 13)
American Journal of Industrial and Business Management     Open Access   (Followers: 24)
American Journal of Medical Quality     Hybrid Journal   (Followers: 7)
American Law and Economics Review     Hybrid Journal   (Followers: 27)
ANALES de la Universidad Central del Ecuador     Open Access   (Followers: 3)
Ankara University SBF Journal     Open Access  
Annales de l'Institut Henri Poincare (C) Non Linear Analysis     Full-text available via subscription   (Followers: 1)
Annals in Social Responsibility     Full-text available via subscription  
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Annual Review of Economics     Full-text available via subscription   (Followers: 34)
Anuario Facultad de Ciencias Económicas y Empresariales     Open Access   (Followers: 2)
Applied Developmental Science     Hybrid Journal   (Followers: 3)
Applied Economics     Hybrid Journal   (Followers: 42)
Applied Economics Letters     Hybrid Journal   (Followers: 29)
Applied Economics Quarterly     Full-text available via subscription   (Followers: 9)
Applied Financial Economics     Hybrid Journal   (Followers: 25)
Applied Mathematical Finance     Hybrid Journal   (Followers: 8)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 6)
Arab Economic and Business Journal     Open Access   (Followers: 4)
Archives of Business Research     Open Access   (Followers: 6)
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Argomenti. Rivista di economia, cultura e ricerca sociale     Open Access   (Followers: 4)
ASEAN Economic Bulletin     Full-text available via subscription   (Followers: 5)
Asia Pacific Business Review     Hybrid Journal   (Followers: 7)
Asia Pacific Journal of Human Resources     Hybrid Journal   (Followers: 313)
Asia Pacific Journal of Innovation and Entrepreneurship     Open Access  
Asia Pacific Viewpoint     Hybrid Journal   (Followers: 1)
Asia-Pacific Journal of Business Administration     Hybrid Journal   (Followers: 5)
Asia-Pacific Journal of Operational Research     Hybrid Journal   (Followers: 3)
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Asian Business Review     Open Access   (Followers: 3)
Asian Case Research Journal     Hybrid Journal   (Followers: 1)
Asian Development Review     Open Access   (Followers: 13)
Asian Economic Journal     Hybrid Journal   (Followers: 8)
Asian Economic Papers     Hybrid Journal   (Followers: 7)
Asian Economic Policy Review     Hybrid Journal   (Followers: 4)
Asian Journal of Accounting and Governance     Open Access   (Followers: 3)
Asian Journal of Business Ethics     Hybrid Journal   (Followers: 9)
Asian Journal of Social Sciences and Management Studies     Open Access   (Followers: 7)
Asian Journal of Sustainability and Social Responsibility     Open Access   (Followers: 1)
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5)
AStA Wirtschafts- und Sozialstatistisches Archiv     Hybrid Journal   (Followers: 5)
ATA Journal of Legal Tax Research     Hybrid Journal   (Followers: 4)
Atlantic Economic Journal     Hybrid Journal   (Followers: 11)
Australasian Journal of Regional Studies, The     Full-text available via subscription   (Followers: 1)
Australian Cottongrower, The     Full-text available via subscription   (Followers: 1)
Australian Economic Papers     Hybrid Journal   (Followers: 32)
Australian Economic Review     Hybrid Journal   (Followers: 3)
Australian Journal of Maritime and Ocean Affairs     Hybrid Journal   (Followers: 9)
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Baltic Journal of Real Estate Economics and Construction Management     Open Access   (Followers: 2)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
BBR - Brazilian Business Review     Open Access   (Followers: 4)
Benchmarking : An International Journal     Hybrid Journal   (Followers: 10)
Benefit : Jurnal Manajemen dan Bisnis     Open Access   (Followers: 1)
BER : Consumer Confidence Survey     Full-text available via subscription   (Followers: 3)
BER : Economic Prospects : An Executive Summary     Full-text available via subscription  
BER : Economic Prospects : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Intermediate Goods Industries Survey     Full-text available via subscription  
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Motor Trade Survey     Full-text available via subscription  
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Trends : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Wholesale Sector Survey     Full-text available via subscription  
Berkeley Business Law Journal     Free   (Followers: 9)
Beykent Üniversitesi Sosyal Bilimler Dergisi     Open Access  
Bio-based and Applied Economics     Open Access   (Followers: 1)
Biodegradation     Hybrid Journal   (Followers: 1)
Biology Direct     Open Access   (Followers: 7)
Bitlis Eren Üniversitesi İktisadi Ve İdari Bilimler Fakültesi Akademik İzdüşüm Dergisi     Full-text available via subscription  
BizInfo (Blace) Journal of Economics, Management and Informatics     Open Access  
Black Enterprise     Full-text available via subscription  
Board & Administrator for Administrators only     Hybrid Journal  
Boletim Técnico do Senac     Open Access  
Border Crossing : Transnational Working Papers     Open Access   (Followers: 4)
Briefings in Real Estate Finance     Hybrid Journal   (Followers: 5)
British Journal of Industrial Relations     Hybrid Journal   (Followers: 36)
Brookings Papers on Economic Activity     Open Access   (Followers: 46)
Brookings Trade Forum     Full-text available via subscription   (Followers: 3)
BRQ Business Research Quarterly     Open Access   (Followers: 2)
Building Sustainable Legacies : The New Frontier Of Societal Value Co-Creation     Full-text available via subscription   (Followers: 1)
Bulletin of Economic Research     Hybrid Journal   (Followers: 17)
Bulletin of Geography. Socio-economic Series     Open Access   (Followers: 5)
Bulletin of Indonesian Economic Studies     Hybrid Journal   (Followers: 3)
Bulletin of the Dnipropetrovsk University. Series : Management of Innovations     Open Access   (Followers: 1)
Business & Entrepreneurship Journal     Open Access   (Followers: 19)
Business & Information Systems Engineering     Hybrid Journal   (Followers: 4)
Business & Society     Hybrid Journal   (Followers: 10)
Business : Theory and Practice / Verslas : Teorija ir Praktika     Open Access   (Followers: 1)
Business and Economic Research     Open Access   (Followers: 7)
Business and Management Horizons     Open Access   (Followers: 12)
Business and Management Research     Open Access   (Followers: 18)
Business and Management Studies     Open Access   (Followers: 11)
Business and Politics     Hybrid Journal   (Followers: 8)
Business and Professional Communication Quarterly     Hybrid Journal   (Followers: 7)
Business and Society Review     Hybrid Journal   (Followers: 5)
Business Economics     Hybrid Journal   (Followers: 9)
Business Ethics Quarterly     Full-text available via subscription   (Followers: 13)
Business Ethics: A European Review     Hybrid Journal   (Followers: 18)
Business Horizons     Hybrid Journal   (Followers: 8)
Business Information Review     Hybrid Journal   (Followers: 14)
Business Management and Strategy     Open Access   (Followers: 41)
Business Research     Hybrid Journal   (Followers: 2)
Business Strategy and the Environment     Hybrid Journal   (Followers: 13)
Business Strategy Review     Hybrid Journal   (Followers: 7)
Business Strategy Series     Hybrid Journal   (Followers: 6)
Business Systems & Economics     Open Access   (Followers: 2)
Business Systems Research Journal     Open Access   (Followers: 5)
Business, Management and Education     Open Access   (Followers: 17)
Business, Peace and Sustainable Development     Full-text available via subscription   (Followers: 3)
Business: Theory and Practice     Open Access  
Bustan     Hybrid Journal  
Cadernos EBAPE.BR     Open Access   (Followers: 1)
Cambridge Journal of Economics     Hybrid Journal   (Followers: 61)
Cambridge Journal of Regions, Economy and Society     Hybrid Journal   (Followers: 10)
Canadian Journal of Administrative Sciences / Revue Canadienne des Sciences de l Administration     Hybrid Journal   (Followers: 1)
Canadian Journal of Economics/Revue Canadienne d`Economique     Hybrid Journal   (Followers: 29)
Canadian journal of nonprofit and social economy research     Open Access   (Followers: 2)
Capitalism and Society     Hybrid Journal   (Followers: 2)
Capitalism Nature Socialism     Hybrid Journal   (Followers: 17)
Cappadocia Academic Review     Open Access  
Case Studies in Business and Management     Open Access   (Followers: 10)
CBU International Conference Proceedings     Open Access   (Followers: 3)
Central European Business Review     Open Access   (Followers: 1)
Central European Journal of Operations Research     Hybrid Journal   (Followers: 5)
Central European Journal of Public Policy     Open Access   (Followers: 2)
CESifo Economic Studies     Hybrid Journal   (Followers: 17)
Chain Reaction     Full-text available via subscription  
Challenge     Full-text available via subscription   (Followers: 4)
China & World Economy     Hybrid Journal   (Followers: 15)
China : An International Journal     Full-text available via subscription   (Followers: 18)
China Economic Journal: The Official Journal of the China Center for Economic Research (CCER) at Peking University     Hybrid Journal   (Followers: 13)
China Economic Review     Hybrid Journal   (Followers: 11)
China Finance Review International     Hybrid Journal   (Followers: 5)
China Nonprofit Review     Hybrid Journal   (Followers: 3)
China perspectives     Open Access   (Followers: 12)
Chinese Economy     Full-text available via subscription  
Ciência & Saúde Coletiva     Open Access   (Followers: 2)
CLIO América     Open Access   (Followers: 1)
Cliometrica     Hybrid Journal   (Followers: 4)
COEPTUM     Open Access  
Community Development Journal     Hybrid Journal   (Followers: 27)
Compensation & Benefits Review     Hybrid Journal   (Followers: 7)
Competition & Change     Hybrid Journal   (Followers: 11)
Competitive Intelligence Review     Hybrid Journal   (Followers: 2)
Competitiveness Review : An International Business Journal incorporating Journal of Global Competitiveness     Hybrid Journal   (Followers: 5)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computer Law & Security Review     Hybrid Journal   (Followers: 17)
Computers & Operations Research     Hybrid Journal   (Followers: 12)
Construction Innovation: Information, Process, Management     Hybrid Journal   (Followers: 14)
Contemporary Wales     Full-text available via subscription   (Followers: 1)
Contributions to Political Economy     Hybrid Journal   (Followers: 5)
Corporate Communications An International Journal     Hybrid Journal   (Followers: 7)
Corporate Philanthropy Report     Hybrid Journal   (Followers: 2)
Corporate Reputation Review     Hybrid Journal   (Followers: 5)
Creative and Knowledge Society     Open Access   (Followers: 9)
Creative Industries Journal     Hybrid Journal   (Followers: 8)

        1 2 3 4 5 6 7 | Last

Journal Cover
Journal Prestige (SJR): 0.695
Citation Impact (citeScore): 2
Number of Followers: 10  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2073-4395
Published by MDPI Homepage  [202 journals]
  • Agronomy, Vol. 8, Pages 79: Agrobiodiversity for Adaptive and Yield Traits
           in Romanian and Italian Barley Cultivars across Four Continental

    • Authors: Fulvia Rizza, Liliana Vasilescu, Franz-W. Badeck, Caterina Morcia, Renzo Alberici, Alexandru Bude, Eliana Alionte, Eugen Petcu, Marina Baronchelli, Nadia Faccini, Donata Pagani, Valeria Terzi
      First page: 79
      Abstract: Within temperate climates the frequency and severity of high and low temperature stresses vary with continentality. The current study reports on the assessment of the performance of 49 barley cultivars across four environments. The cultivars stem from 50 years of breeding activities in Romania and Italy, in two temperate climates that differ in continentality. The plants were phenotyped through stress monitoring, measurements of yield and yield related traits as well as laboratory stress tolerance tests. Genotypes for alleles of vernalisation and photoperiod genes were determined. These genes were significantly associated with frost damage in the field and frost tolerance in laboratory tests. Grain yield (GY) was more closely correlated with the number of grain sinks than with the degree of grain filling indicating major limitations in the vegetative growth phase and during grain initiation. High temperature stress during the grain filling phase significantly reduced GY. Frost damage due to freezing temperatures below −10 °C when plants were not protected by snow cover significantly reduced GY of sensitive cultivars. The characterisation of environmental cues that cause stresses with yield penalties as well as the susceptibility of genetically different cultivars lay the ground for future targeted selection.
      Citation: Agronomy
      PubDate: 2018-05-23
      DOI: 10.3390/agronomy8060079
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 80: Linkage Map of a Gene Controlling Zero Tannins
           (zt-1) in Faba Bean (Vicia faba L.) with SSR and ISSR Markers

    • Authors: Wanwei Hou, Xiaojuan Zhang, Qingbiao Yan, Ping Li, Weichao Sha, Yingying Tian, Yujiao Liu
      First page: 80
      Abstract: Faba bean (Vicia faba L.), a partially allogamous species, is rich in protein. Condensed tannins limit the use of faba beans as food and feed. Two recessive genes, zt-1 and zt-2, control the zero tannin content in faba bean and promote a white flower phenotype. To determine the inheritance and develop a linkage map for the zt-1 gene in the faba bean germplasm M3290, F2 and F3 progenies were derived from the purple flower and high tannin content genotypes Qinghai12 and zt-1 line M3290, respectively. Genetic analysis verified a single recessive gene for zero tannin content and flower colour. In total, 596 SSR markers and 100 ISSR markers were used to test the polymorphisms between the parents and bulks for the contrasting flower colour via Bulked Segregant Analysis (BSA). Subsequently, six SSR markers and seven ISSR markers were used to genotype the entire 413 F2 population. Linkage analysis showed that the zt-1 gene was closely linked to the SSR markers SSR84 and M78, with genetic distances of 2.9 and 5.8 cM, respectively. The two flanked SSR markers were used to test 34 faba bean genotypes with different flower colours. The closely linked SSR marker SSR84 predicted the zt-1 genotypes with absolute accuracy. The results from the marker-assisted selection (MAS) from this study could provide a solid foundation for further faba bean breeding programmes.
      Citation: Agronomy
      PubDate: 2018-05-23
      DOI: 10.3390/agronomy8060080
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 81: Starch Biosynthesis in Crop Plants

    • Authors: Ian Tetlow
      First page: 81
      Abstract: Starch is a water-insoluble polyglucan synthesized inside the plastids of plant tissues to provide a store of carbohydrate. Starch harvested from plant storage organs has probably represented the major source of calories for the human diet since before the dawn of civilization. Following the advent of agriculture and the building of complex societies, humans have maintained their dependence on high-yielding domesticated starch-forming crops such as cereals to meet food demands, livestock production, and many non-food applications. The top three crops in terms of acreage are cereals, grown primarily for the harvestable storage starch in the endosperm, although many starchy tuberous crops also provide an important source of calories for various communities around the world. Despite conservation in the core structure of the starch granule, starches from different botanical sources show a high degree of variability, which is exploited in many food and non-food applications. Understanding the factors underpinning starch production and its final structure are of critical importance in guiding future crop improvement endeavours. This special issue contains reviews on these topics and is intended to be a useful resource for researchers involved in improvement of starch-storing crops.
      Citation: Agronomy
      PubDate: 2018-05-25
      DOI: 10.3390/agronomy8060081
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 82: “Alperujo” Compost Improves the Ascorbate
           (Vitamin C) Content in Pepper (Capsicum annuum L.) Fruits and Influences
           Their Oxidative Metabolism

    • Authors: Germán Tortosa, Salvador González-Gordo, Carmelo Ruiz, Eulogio J. Bedmar, José M. Palma
      First page: 82
      Abstract: “Alperujo” compost was evaluated as an organic fertiliser for pepper growth under greenhouse conditions. Even though the total nitrogen applied was similar, plants only grown with composts experienced a development decline as compared to those grown with standard nutrient solution. This was perhaps because nitrogen from the compost was essentially organic, and not easily available for roots. When, alternatively, the compost was supplemented with nitrate, a synergetic effect was observed, favouring plant development and fruit yield, simultaneously with the increase of compost rates. Compost affected the oxidative metabolism of pepper plants by increasing their antioxidative enzyme activities catalase and superoxide dismutases and the non-enzymatic antioxidants ascorbate and glutathione. Overall, when nitrogen limitation occurred and only compost was used as fertiliser, an oxidative stress took place, whereas in plants grown with nitrate-supplemented compost it did not. Furthermore, these pepper plants experienced a yield increase and, more importantly, an enhancement of the ascorbate content.
      Citation: Agronomy
      PubDate: 2018-05-25
      DOI: 10.3390/agronomy8060082
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 83: Physiological and Agronomic Strategies to
           Increase Mungbean Yield in Climatically Variable Environments of Northern

    • Authors: Yashvir S. Chauhan, Rex Williams
      First page: 83
      Abstract: Mungbean (Vigna radiata (L.) Wilczek) in Australia has been transformed from a niche opportunistic crop into a major summer cropping option for dryland growers in the summer-dominant rainfall regions of Queensland and New South Wales. This transformation followed stepwise genetic improvements in both grain yields and disease resistance. For example, more recent cultivars such as ‘Crystal’, ‘Satin II’, and ‘Jade-AU‘ have provided up to a 20% yield advantage over initial introductions. Improved agronomic management to enable mechanised management and cultivation in narrow (<50 cm) rows has further promised to increase yields. Nevertheless, average yields achieved by growers for their mungbean crops remain less than 1 t/ha, and are much more variable than other broad acre crops. Further increases in yield and crop resilience in mungbean are vital. In this review, opportunities to improve mungbean productivity have been analysed at four key levels including phenology, leaf area development, dry matter accumulation, and its partitioning into grain yield. Improving the prediction of phenology in mungbean may provide further scope for genetic improvements that better match crop duration to the characteristics of target environments. There is also scope to improve grain yields by increasing dry matter production through the development of more efficient leaf canopies. This may introduce additional production risks as dry matter production depends on the amount of available water, which varies considerably within and across growing regions in Australia. Improving crop yields by exploiting G × E × M interactions related to cultivar photo-thermal sensitivities and make better use of available water in these variable environments is likely to be a less risky strategy. Improved characterisation of growing environments using modelling approaches could also better define and identify the risks of major abiotic constraints. This would assist in optimising breeding and management strategies to increase grain yield and crop resilience in mungbean for the benefit of growers and the industry.
      Citation: Agronomy
      PubDate: 2018-05-26
      DOI: 10.3390/agronomy8060083
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 84: Breeding Maize for Tolerance to Acidic Soils:
           A Review

    • Authors: Liliane Ngoune Tandzi, Charles Shelton Mutengwa, Eddy Léonard Mangaptche Ngonkeu, Vernon Gracen
      First page: 84
      Abstract: Acidic soils hamper maize (Zea mays L.) production, causing yield losses of up to 69%. Low pH acidic soils can lead to aluminum (Al), manganese (Mn), or iron (Fe) toxicities. Genetic variability for tolerance to low soil pH exists among maize genotypes, which can be exploited in developing high-yielding acid-tolerant maize genotypes. In this paper, we review some of the most recent applications of conventional and molecular breeding approaches for improving maize yield under acidic soils. The gaps in breeding maize for tolerance to low soil pH are highlighted and an emphasis is placed on promoting the adoption of the numerous existing acid soil-tolerant genotypes. While progress has been made in breeding for tolerance to Al toxicity, little has been done on Mn and Fe toxicities. More research inputs are therefore required in: (1) developing screening methods for tolerance to manganese and iron toxicities; (2) elucidating the mechanisms of maize tolerance to Mn and Fe toxicities; and, (3) identifying the quantitative trait loci (QTL) responsible for Mn and Fe tolerance in maize cultivars. There is also a need to raise farmers’ and other stakeholders’ awareness of the problem of Al, Mn, and Fe soil toxicities to improve the adoption rate of the available acid-tolerant maize genotypes. Maize breeders should work more closely with farmers at the early stages of the release process of a new variety to facilitate its adoption level. Researchers are encouraged to strengthen their collaboration and exchange low soil pH-tolerant maize germplasm.
      Citation: Agronomy
      PubDate: 2018-05-29
      DOI: 10.3390/agronomy8060084
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 85: Effects of Dosage and Spraying Volume on
           Cotton Defoliants Efficacy: A Case Study Based on Application of Unmanned
           Aerial Vehicles

    • Authors: Fang Xin, Jing Zhao, Yueting Zhou, Guobin Wang, Xiaoqiang Han, Wei Fu, Jizhong Deng, Yubin Lan
      First page: 85
      Abstract: Plant protection unmanned aerial vehicles (UAVs) consist of light and small UAVs with pesticide spraying equipment. The advantage of UAVs is using low-volume spray technology to replace the traditional large-volume mass locomotive spray technology. Defoliant spraying is a key link in the mechanized cotton harvest, as sufficient and uniform spraying can improve the defoliation quality and decrease the cotton trash content. However, cotton is planted at high density in Xinjiang, with leaves in two adjacent rows seriously overlapped, making the lower leaves poorly sprayed. Thus, the defoliation effect is poor, and the cotton quality is degraded. To improve the effect of defoliation and reduce the losses caused by boom sprayer rolling, the effect of defoliant dosage on defoliation, boll opening, absorption and decontamination in cotton leaves and the effect of spraying volume on absorption and decontamination in cotton leaves sprayed by UAVs are studied. The pooled results indicate that plant protection UAVs could be used for cotton defoliants spraying with a twice defoliant spraying strategy, and the defoliant dosage has no significant effect on seed cotton yield and fiber quality in Xinjiang. The residue of thidiazuron in cotton leaves reaches the maximum at four days after spraying, the residue of diuron in cotton leaves reaches the maximum at one day after second spraying. The thidiazuron and diuron residues are increased with spraying volume at rang of 17.6–29.0 L/ha. When the spraying volume is less than 17.6 L/ha, the residue of thidiazuron and diuron is reduced. The research results could provide a reference for further optimization of the spraying parameters of cotton defoliant by plant protection UAVs.
      Citation: Agronomy
      PubDate: 2018-05-30
      DOI: 10.3390/agronomy8060085
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 86: Water-Stressed Loquat Trees Need More Time and
           Heat to Ripen Their Fruits

    • Authors: Julián Cuevas, Virginia Pinillos, Mercedes Pérez-Macías, Francisca Alonso, Mónica González, Juan José Hueso
      First page: 86
      Abstract: To determine if water-stressed trees need more time and heat to mature their fruits, we compared chronological and thermal time from bloom to harvest among control fully-irrigated ‘Algerie’ loquat trees and trees suffering prior-to-bloom deficit irrigation (DI). Heat requirement calculation was performed using the double sine method with a lower threshold temperature of 3 °C. The results show that the greater the blooming advancement achieved by DI, the longer the period to mature the fruits. Such a pattern indicates that the longer duration for bloom-harvest period under DI is due to a displacement of the reproductive phenology to cooler dates. However, some effects of DI on heat requirements for ripening persist, indicating a slower fruit development in some, but not all, DI treatments. The differences in fruit development rate between fully-irrigated and water-stressed trees were established during the phase of rapid fruit growth. The comparison of water stress effects on sink (flower size and seed number) and source (leaf number and size, gas exchange and mineral and carbohydrate nutrition) of DI treatments seems to indicate that the amount of stored reserves in the leaves to sustain early fruit development is the most plausible reason behind the increase in thermal time between bloom and harvest in water-stressed loquats.
      Citation: Agronomy
      PubDate: 2018-06-01
      DOI: 10.3390/agronomy8060086
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 87: The Effect of Barley Cover Crop Residue and
           Herbicide Management on the Foliar Arthropod Community in No-Till Soybeans

    • Authors: Armando Rosario-Lebron, Alan W. Leslie, Guihua Chen, Cerruti R. R. Hooks
      First page: 87
      Abstract: Cover cropping has long been used as a method of reducing soil erosion, increasing soil quality, and suppressing weeds. However, the effects of cover crops in local farming systems are varied and can be affected by timing and method of termination. Field experiments were conducted at two sites in Maryland, USA during the 2013 and 2014 growing seasons to examine how varying the date and method of terminating a barley (Hordeum vulgare) cover crop affects the arthropod communities in succeeding no-till soybean (Glycine max). Experimental treatments included early-kill with pre- and post-emergent herbicides (EK), late-kill with pre- and post-emergent herbicides (LK), late-kill with a flail mower and pre-emergent herbicide (FM), and a fallow/bare-ground check with pre- and post-emergent herbicides (BG). Terminating barley late, just prior to soybean planting, resulted in significantly greater biomass accumulation in LK and FM than EK. However, method and timing of termination had no effect on the community of pest and beneficial arthropods in the soybean canopy. Results from this experiment suggest that terminating the cover crop early or late (just prior to crop planting) or using a mower or post-emergent herbicide will result in a similar community of arthropods within the soybean canopy.
      Citation: Agronomy
      PubDate: 2018-06-01
      DOI: 10.3390/agronomy8060087
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 88: Biomass Production and Composition of
           Temperate and Tropical Maize in Central Iowa

    • Authors: Pedro Infante, Ken Moore, Charlie Hurburgh, Paul Scott, Sotirios Archontoulis, Andrew Lenssen, Shui-zhang Fei
      First page: 88
      Abstract: Bioethanol production in the midwestern U.S. has largely focused on maize (Zea mays L.) grain for starch-based ethanol production. There has been growing interest in lignocellulosic biomass as a feedstock for biofuels. Because maize adapted to the tropics does not initiate senescence as early as temperate-adapted maize, using a tropical germplasm could improve biomass yield. This study compares the suitability of temperate and tropical maize with differing relative maturities as feedstocks for bioethanol production. Field trials were established in central Iowa during the 2014 and 2015 growing seasons. Six hybrids of different relative maturities were grown at two levels of N fertilization and two row spacings to evaluate total biomass production and feedstock quality under midwestern U.S. conditions. Total biomass, height at the final leaf collar, stem diameter at one meter above ground, and lignocellulose concentration were measured at harvest. Tropical maize was taller and had greater non-grain and total biomass production (15% more than temperate maize), while temperate maize had greater grain yield and grain starch, as well as earlier maturation. Narrower row spacing had greater biomass and grain yield. Nitrogen fertilization rate affected grain and feedstock composition. Tropical maize had lower cellulose, lignin, and ash concentrations and higher nitrogen at harvest than that of temperate maize. Conversely, temperate maize had greater ash, cellulose, and lignin concentrations. Tropical maize planted at high densities has high potential as a feedstock for bioethanol production in the U.S. Midwest.
      Citation: Agronomy
      PubDate: 2018-06-01
      DOI: 10.3390/agronomy8060088
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 89: Olive Water Use, Crop Coefficient, Yield, and
           Water Productivity under Two Deficit Irrigation Strategies

    • Authors: Francisco L. Santos
      First page: 89
      Abstract: Reports on the annual effects of deficit irrigation regimes on olive trees are critical in shedding light on their impacts on water use, yield, and water productivity in distinct olive growing climate regions of the world. From the account of a four-year experiment, the aim of this work is to add insight into such effects on olive growing in southern Portugal. We worked with trees in an intensive ‘Cobrançosa’ orchard (300 trees ha−1) under full irrigation (FI) treatment and two regulated deficit irrigation (DI) treatments designed to replace around 70% and 50% of the FI water supply, respectively. Crop transpiration (T), irrigation water use (IWU), total water use (TWU), irrigation water use efficiency (IWUE), yield (Ya), and water productivity (WP) obtained from all treatments were analyzed, as well as their crop coefficients (Kc), simulated with the SIMDualKc software application for root zone and soil water balance based on the FAO dual crop coefficients. As expected, IWUE of the 50DI treatment was the highest among treatments, with 70DI being slightly lower. Ya showed alternate bearing with an “on-off” year sequence and was consistently higher for the 70DI treatment. WP (the ratio of Ya to IWU) values for the 70DI treatment were also consistently the highest among all treatments and years. The mean simulated Kc act values for 70DI and 50DI for the initial, mid-, and end-season compared well to the FAO56 Kc for olive crops. In general, to rank the irrigation treatments, 70DI presented the highest conversion efficiency among all treatments and years, providing a suitable DI alternative for our ‘Cobrançosa’ orchard. The 50DI treatment may be an attractive DI regime to undertake under scarce farm water resources or the expansion of olive hectares under water constraints.
      Citation: Agronomy
      PubDate: 2018-06-03
      DOI: 10.3390/agronomy8060089
      Issue No: Vol. 8, No. 6 (2018)
  • Agronomy, Vol. 8, Pages 58: Development of ent-kaurene Oxidase-Based
           Conserved Intron Spanning Primers for Species Identification in the Genus
           Poa (Poaceae; Bluegrass)

    • Authors: Jonathan M. LaMantia, Ambika Chandra, David R. Huff
      First page: 58
      Abstract: Interspecific hybridization has been attempted to combine the heat and drought of Poa arachnifera Torr. with the turf quality characteristics of several Poa species. Confirmation of an F1 hybrid through morphological analysis of vegetative and flowering characteristics is often time consuming and ambiguous. Ent-kaurene oxidase (KO) has been sequenced in rice, barley, and wheat. In rice, each of the five copies of KO gene has unique lengths for the first intron. Conserved intron spanning primers (CISP) can be used as a DNA marker to exploit variations of intron lengths that flank conserved gene sequences. In the present study, we developed CISP to sequence partial genomic fragments of the KO gene from seven Poa species. Through sequence analysis, species-specific primers were also developed to produce co-dominant markers that can be used to identify interspecific hybrids between Texas bluegrass and six other Poa species used in the present study.
      Citation: Agronomy
      PubDate: 2018-04-24
      DOI: 10.3390/agronomy8050058
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 59: Characterizing Spatial Variability in Soil
           Water Content for Precision Irrigation Management

    • Authors: Alfonso de Lara, Raj Khosla, Louis Longchamps
      First page: 59
      Abstract: Among one of the many challenges in implementing precision irrigation is to obtain an accurate characterization of the soil water content (SWC) across spatially variable fields along the crop growing season. The accuracy of characterizing SWC has been tested primarily on a small-scale and has received little attention from the scientific community at the field scale. Hence, the objective of this study was to assess the characterization of the spatial distribution of soil water content at the field scale by the apparent electrical conductivity (ECa). In evaluating the current aim, ECa survey was compared against repeated measurements of SWC at five depths using neutron probe. Results showed that mean SWC was different across ECa derived management zones, which indicates that on a macro-scale, soil ECa could effectively characterize the mean differences in SWC across management zones. Results also showed that deep ECa (0–150 cm) survey outperformed shallow survey (0–75 cm). Considering other soil properties, such as organic matter content and salt content, further improved the relationship between SWC and ECa.
      Citation: Agronomy
      PubDate: 2018-04-24
      DOI: 10.3390/agronomy8050059
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 60: Genome-Wide Linkage Mapping of Quantitative
           Trait Loci for Late-Season Physiological and Agronomic Traits in Spring
           Wheat under Irrigated Conditions

    • Authors: Yuxiu Liu, Rui Wang, Yin-gang Hu, Jianli Chen
      First page: 60
      Abstract: Many late-season physiological traits affect grain yield in wheat, either directly or indirectly. However, information on the genetic control of yield-related traits is still limited. In this study, we aimed to identify quantitative trait loci (QTL) for canopy temperature and chlorophyll content index during anthesis (CTa and CCIa, respectively), the mid grain-filling stage (CTg1 and CCIg1, respectively), and the late grain-filling stage (CTg2 and CCIg2, respectively) as well as for plant height (PH), thousand kernels weight (TKW), and grain yield (GY) using genome-wide linkage mapping. To this end, a double haploid population derived from a cross between two high yielding wheat cultivars, UI Platinum and SY Capstone, was phenotyped in four irrigated environments and genotyped using the wheat 90K iSelect platform and simple sequence repeats. The genotypic data were used to construct a high-density genetic map of 43 linkage groups (LGs) with a total length of 3594.0 cm and a marker density of 0.37 cm. A total of 116 QTL for all nine traits was detected on 33 LGs, spreading to all wheat chromosomes, except for Chr. 7D. Of these, six QTL (CTa.ui-4B.1, Q.CTg1.ui-5B-2.1, Q.CTg2.ui-6B.1, Q.PH.ui-6A-2.1, Q.TKW.ui-2D-1, and Q.GY.ui-6B) were consistently detected in more than three irrigated environments, called as stable QTL. Additionally, we identified 26 QTL clusters for more than two traits, of which the top four were located on Chromosomes 4A-1, 1B-1, 5B-2, and 2D-1. Overall, the stable QTL significantly related with grain yield, QTL clusters, and linked molecular markers identified in this study, may be useful in marker-assisted selection in early generation and early growth stage for grain yield improvement.
      Citation: Agronomy
      PubDate: 2018-04-25
      DOI: 10.3390/agronomy8050060
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 61: Developmental Morphology and Biomass Yield of
           Upland and Lowland Switchgrass Ecotypes Grown in Iowa

    • Authors: Muhammad Aurangzaib, Kenneth J. Moore, Andrew W. Lenssen, Sotirios V. Archontoulis, Emily A. Heaton, Shuizhang Fei
      First page: 61
      Abstract: Sustainable development of the bioenergy industry will depend upon the amount and quality of bioenergy feedstock produced. Switchgrass (Panicum virgatum L.) is a model lignocellulosic bioenergy crop but critical information is lacking for improved management, growth, and development simulation model calibration. A field study was conducted near Ames, IA during 2012–2013 with the objective to evaluate upland (“Cave-in-Rock”, ‘Trailblazer’ and ‘Blackwell’) and lowland (“Kanlow” and “Alamo”) switchgrass ecotypes for harvest timing on morphology (i.e., phenology, leaf area index (LAI), and biomass yield). The experiment used a randomized complete block design, with three upland and two lowland varieties harvested at six dates annually. In both years, delaying harvest to later maturity increased biomass yield; lowland cultivars produced greater biomass yield (6.15 tons ha−1) than upland ecotypes (5.10 tons ha−1). Lowland ecotypes had delayed reproductive development compared with upland ecotypes. At the end of both growing seasons, upland ecotypes had greater mean stage count (MSC) than lowland ecotypes. “Cave-in-Rock” had greatest MSC and LAI, but did not produce the greatest biomass. Relationships were nonlinear between MSC and biomass yield, with significant cultivar–year interaction. The relationship between biomass yield and MSC will be useful for improving switchgrass, including cultivar selection, fertilizer application, and optimum harvest time.
      Citation: Agronomy
      PubDate: 2018-04-28
      DOI: 10.3390/agronomy8050061
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 62: Genotype-by-Environment Interaction and Yield
           Stability of Maize Single Cross Hybrids Developed from Tropical Inbred

    • Authors: Hortense Noëlle Apala Mafouasson, Vernon Gracen, Martin Agyei Yeboah, Godswill Ntsomboh-Ntsefong, Liliane Ngoune Tandzi, Charles Shelton Mutengwa
      First page: 62
      Abstract: Nitrogen (N) is one of the most important nutrients required for high productivity of the maize plant. In most farmers’ fields in Sub-Saharan Africa (SSA), there is low availability of N in the soil mainly due to continuous cultivation of the land, crop residues removal, little or no application of fertilizers and rapid leaching. There is a need to develop low N tolerant and adapted maize genotypes. Evaluation of maize genotypes under different nitrogen conditions would therefore be useful in identifying genotypes that combine stability with high yield potential for both stress and non-stress environment. Eighty maize hybrids were evaluated at Mbalmayo and Nkolbisson in Cameroon, during 2012 and 2013 minor and major cropping seasons across 11 environments under low and high N conditions. The objectives of the study were: (i) to determine the effect of genotype x environment interaction (G × E) on grain yield and yield stability of single cross maize hybrids across low N and optimum N environments and (ii) to identify genotypes to recommend for further use in the breeding program. Yield data of 80 hybrids were analyzed initially and the analysis of 20 best performing genotypes was further performed for a better visualization and interpretation of the results. Combined analysis of variance showed highly significant G × E effects for grain yield. The GGE biplot analysis divided the study area into three mega environments: one related to the major cropping season while the two others were related to the minor cropping season. The grain yield of the 20 highest yielding hybrids ranged from 4484.7 to 5198.3 kg ha−1. Hybrid 1368 × 87036 was the highest yielding in the minor season while the most outstanding hybrid, TL-11-A-1642-5 × 87036 was the best for the major season. The latter hybrid showed the potential for production across environments and should therefore be further tested in multiple environments to confirm consistency of its high yield performance and stability, and to facilitate its release as a commercial hybrid. High yielding but not stable hybrids across environments could be recommended for the specific environments where they performed well.
      Citation: Agronomy
      PubDate: 2018-05-01
      DOI: 10.3390/agronomy8050062
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 63: High-Throughput Phenotyping of Seed/Seedling
           Evaluation Using Digital Image Analysis

    • Authors: Chongyuan Zhang, Yongsheng Si, Jacob Lamkey, Rick A. Boydston, Kimberly A. Garland-Campbell, Sindhuja Sankaran
      First page: 63
      Abstract: Image-based evaluation of phenotypic traits has been applied for plant architecture, seed, canopy growth/vigor, and root characterization. However, such applications using computer vision have not been exploited for the purpose of assessing the coleoptile length and herbicide injury in seeds. In this study, high-throughput phenotyping using digital image analysis was applied to evaluate seed/seedling traits. Images of seeds or seedlings were acquired using a commercial digital camera and analyzed using custom-developed image processing algorithms. Results from two case studies demonstrated that it was possible to use image-based high-throughput phenotyping to assess seeds/seedlings. In the seedling evaluation study, using a color-based detection method, image-based and manual coleoptile length were positively and significantly correlated (p < 0.0001) with reasonable accuracy (r = 0.69–0.91). As well, while using a width-and-color-based detection method, the correlation coefficient was also significant (p < 0.0001, r = 0.89). The improvement of the germination protocol designed for imaging will increase the throughput and accuracy of coleoptile detection using image processing methods. In the herbicide study, using image-based features, differences between injured and uninjured seedlings can be detected. In the presence of the treatment differences, such a technique can be applied for non-biased symptom rating.
      Citation: Agronomy
      PubDate: 2018-05-03
      DOI: 10.3390/agronomy8050063
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 64: Salt Stress Effects on Avocado (Persea
           americana Mill.) Plants with and without Seaweed Extract (Ascophyllum
           nodosum) Application

    • Authors: Claudia Bonomelli, Valentina Celis, Gian Lombardi, Johanna Mártiz
      First page: 64
      Abstract: Salinity is one of the major factors limiting avocado yield, primarily due to the high concentration of ions in irrigation water. An experiment was conducted on 2 year old avocado plants (Persea americana Mill.) cv. Hass, grafted onto Duke 7 clonal rootstock growing in pots, to determine the effect of salt stress on growth, as well as physiological and biochemical responses, and the effect of seaweed extract (Ascophyllum nodosum) on salinity stress. Treatments consisted of different types of irrigation water: distilled water, 9 mM NaCl water, distilled water + 2.25 mL of seaweed extract, 9 mM NaCl water + 2.25 mL of seaweed extract and, 9 mM NaCl water + 1.5 mL of seaweed extract. The irrigation treatment was applied every 15 days for 8 months. Treatments with salt reduced plant growth by approximately 50% of the fresh weight of all avocado plant tissues. Seaweed extract reduced the effects of abiotic stress only at an early stage, and increased potassium (K) and calcium (Ca) concentrations in leaves.
      Citation: Agronomy
      PubDate: 2018-05-04
      DOI: 10.3390/agronomy8050064
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 65: The Effects of Rice Straw and Biochar
           Applications on the Microbial Community in a Soil with a History of
           Continuous Tomato Planting History

    • Authors: Yiming Zhang, Yufeng Liu, Guoxian Zhang, Xiaoou Guo, Zhouping Sun, Tianlai Li
      First page: 65
      Abstract: Soil microbial abundance and diversity change constantly in continuous cropping systems, resulting in the prevalence of soil-borne pathogens and a decline in crop yield in solar greenhouses. To investigate the effects of rice straw and biochar on soil microbial abundance and diversity in soils with a history of continuous planting, three treatments were examined: mixed rice straw and biochar addition (RC), rice straw addition (R), and biochar addition (C). The amount of C added in each treatment group was 3.78 g kg−1 soil. Soil without rice straw and biochar addition was treated as a control (CK). Results showed that RC treatment significantly increased soil pH, available nitrogen (AN), available phosphorus (AP), and potassium (AK) by 40.3%, 157.2%, and 24.2%, respectively, as compared to the CK soil. The amount of soil labile organic carbon (LOC), including readily oxidizable organic carbon (ROC), dissolved organic carbon (DOC), and light fraction organic carbon (LFOC), was significantly greater in the RC, R, and C treatment groups as compared to CK soil. LOC levels with RC treatment were higher than with the other treatments. Both rice straw and biochar addition significantly increased bacterial and total microbial abundance, whereas rice straw but not biochar addition improved soil microbial carbon metabolism and diversity. Thus, the significant effects of rice straw and biochar on soil microbial carbon metabolism and diversity were attributed to the quantity of DOC in the treatments. Therefore, our results indicated that soil microbial diversity is directly associated with DOC. Based on the results of this study, mixed rice straw and biochar addition, rather than their application individually, might be key to restoring degraded soil.
      Citation: Agronomy
      PubDate: 2018-05-04
      DOI: 10.3390/agronomy8050065
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 66: Alleviation of Drought Stress by Nitrogen
           Application in Brassica campestris ssp. Chinensis L.

    • Authors: Xin Xiong, Liying Chang, Muhammad Khalid, Jingjin Zhang, Danfeng Huang
      First page: 66
      Abstract: To assess the influence of drought stress on the growth and nitrogen nutrition status of pakchoi (Brassica campestris ssp. Chinensis L.) at different nitrogen (N) levels, the changes in N accumulation and enzyme activities involved in N assimilation were investigated. The drought was induced by adding polyethylene glycol (PEG) under hydroponic culture conditions. Pakchoi seedlings were exposed to a modified nutrient solution with different nitrogen concentration (N1, N2, and N3 represent 2, 9 and 18 mM NaNO3, respectively) and osmotic potential (W1, W2 and W3 represent 0, 60 and 120 g·L−1 PEG 6000) in a full factorial, replicated randomized block design. A short time (seven days) of drought stress caused a significant decline in plant water content, transpiration rate, shoot biomass and shoot nitrogen concentration. Increasing N availability considerably alleviate drought stress by increasing the content of total free amino acids in the roots, promoting the acceleration of root biomass accumulation, and improving the activities of nitrate reductase (NR; EC and glutamine synthetase (GS; EC which would reduce moisture limitations. The results suggested that pakchoi supplied with relative higher N had better growth performance under drought stress.
      Citation: Agronomy
      PubDate: 2018-05-04
      DOI: 10.3390/agronomy8050066
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 67: Diluted Sugar Mill Effluent Application with
           PGPR Improves the Performance of Maize (Zea mays L.) under an Arid Climate

    • Authors: Muhammad Ijaz, Muhammad Sarfraz, Ahmad Nawaz, Tauqeer Ahmad Yasir, Ahmad Sher, Abdul Sattar, Allah Wasaya
      First page: 67
      Abstract: The disposal of sugar mill effluent is a serious matter of concern for the sugar industry. In this regard, the dilution of sugar mill effluent in combination with plant growth promoting rhizobacteria (PGPR) might be a viable option for improving crop growth. In this study, we evaluated the potential of diluted sugar mill effluent (SME) and PGPR to improve maize (Zea mays L.) performance. Seeds of a maize hybrid (Pioneer 1543) were sown in 20 kg soil-filled pots. The pots were irrigated with various sugar mill effluent concentrations (viz. 0, 15%, 30%, 45%, 60%, 75% and 100% v/v). The results indicated that application of SME up to a concentration of 75% improved the stay-green, leaf emergence, growth and productivity of maize. However, the application of SME at a concentration of 100% was detrimental for maize plants and decreased the maize growth. The application of PGPR was also beneficial for improvement in stay-green, leaf emergence, growth and productivity of maize as compared with control (no PGPR application). In conclusion, the use of SME at concentration of 75% in combination with PGPR was the most effective method for improvement in stay-green, leaf emergence, growth and productivity of maize.
      Citation: Agronomy
      PubDate: 2018-05-04
      DOI: 10.3390/agronomy8050067
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 68: GWAS for Fusarium Head Blight Related Traits
           in Winter Wheat (Triticum Aestivum L.) in an Artificially Warmed Treatment

    • Authors: Elisane W. Tessmann, David A. Van Sanford
      First page: 68
      Abstract: Global temperature increases will affect Fusarium head blight (FHB) levels in wheat (Triticum aestivum L.). A pressing question is whether current sources of resistance will be effective in a warmer environment. We evaluated phenotypic response to disease in 238 soft winter wheat breeding lines and cultivars grown in 2015–2016 and 2016–2017 under control and warmed (+3 °C) conditions. Warming was achieved with heating cables buried 3 cm in the rhizosphere. We measured heading date, plant height, yield, FHB rating, Fusarium damaged kernels (FDK), deoxynivalenol (DON), leaf blotch rating, powdery mildew rating and leaf rust rating. There were significant (p < 0.01) differences among genotypes for all traits measured. Genome-wide association study (GWAS) identified 19 and 10 significant SNPs in the control and warmed treatments, respectively. FDK and DON levels were often significantly (p < 0.05) higher in warmed than in control when we contrasted alleles at important quantitative trait locus (QTL) such as Fhb1, Rht-B1 and D1 and all vernalization and photoperiod loci. Increased rhizosphere temperature resulted in a significantly (p < 0.01) earlier heading date (~3.5 days) both years of the study. Rank correlation between warmed and control treatments was moderate (r = 0.56). Though encouraging, it indicates that selection for performance under warming should be carried out in a warmed environment.
      Citation: Agronomy
      PubDate: 2018-05-05
      DOI: 10.3390/agronomy8050068
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 69: Resource Use Efficiencies of C3 and C4 Cereals
           under Split Nitrogen Regimes

    • Authors: Zartash Fatima, Qaiser Abbas, Amna Khan, Sajjad Hussain, Muhammad Arif Ali, Ghulam Abbas, Haseeb Younis, Shahrish Naz, Muhammad Ismail, Muhammad Imran Shahzad, Muhammad Nadeem, Umair Farooq, Shahzad Usman Khan, Kashif Javed, Azhar Ali Khan, Mukhtar Ahmed, Muhammad Azam Khan, Shakeel Ahmad
      First page: 69
      Abstract: Resources are limited, thus improving resource use efficiency is a key objective for cereal-based cropping systems. This field study was carried out to quantify resource use efficiencies in selected C3 and C4 cereals under split nitrogen (N) application regimes. The study included the following treatments: six cereals (three C3: wheat, oat, and barley; and three C4: maize, millet, and sorghum) and four split N application regimes (NS1 = full amount of N at sowing; NS2 = half N at sowing + half N at first irrigation; NS3 = ⅓ N at sowing + ⅓ N at first irrigation + ⅓ N at second irrigation; NS4 = ¼ N at sowing + ¼ N at first irrigation + ¼ N at second irrigation + ¼ N at third irrigation). Results revealed that C4 cereals out-yielded C3 cereals in terms of biomass production, grain yield, and resource use efficiencies (i.e., radiation use efficiency (RUE) and nitrogen use efficiency (NUE)), while splitting N into three applications proved to be a better strategy for all of the selected winter and summer cereals. The results suggest that C4 cereals should be added into existing cereal-based cropping systems and N application done in three installments to boost productivity and higher resource use efficiency to ensure food security for the burgeoning population.
      Citation: Agronomy
      PubDate: 2018-05-09
      DOI: 10.3390/agronomy8050069
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 70: Variation of Agronomic Traits of Ravenna Grass
           and Its Potential as a Biomass Crop

    • Authors: Tim L. Springer
      First page: 70
      Abstract: Ravenna grass (Tripidium ravennae) is a tall robust bunchgrass with potential as an energy crop. The aim was to investigate the variation of agronomic traits of Ravenna grass. Univariate analyses of traits were conducted on 95 plants from 2013 to 2017. The traits were: biomass yield per plant; C, N, and ash concentrations; leaf and culm sap sucrose concentrations; percentage seed set, and the number of caryopses per panicle. In 2013, the biomass yield averaged 0.21 ± 0.09 kg per plant (mean ± the standard deviation). In 2014 to 2017, the yield averaged from 3.9 ± 0.8 kg per plant to 7.5 ± 1.8 kg per plant. Carbon concentration was generally higher than other energy crops, while N and ash concentrations were generally lower. Leaf sap sucrose ranged from 24.4 ± 4.6 g kg−1 in 2016 to 41.6 ± 7.6 g kg−1 in 2013. Culm sap sucrose varied from approximately 1.6 to 2.1 times that of leaf sap depending upon the harvest year. The percentage seed set varied between years ranging from 37.2 ± 12.4% to 56.6 ± 9.8%, and the mean number of caryopses per panicle varied from 4,770 ± 2,000 to 11,470 ± 3,075.
      Citation: Agronomy
      PubDate: 2018-05-12
      DOI: 10.3390/agronomy8050070
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 71: Existing and Potential Statistical and
           Computational Approaches for the Analysis of 3D CT Images of Plant Roots

    • Authors: Zheng Xu, Camilo Valdes, Jennifer Clarke
      First page: 71
      Abstract: Scanning technologies based on X-ray Computed Tomography (CT) have been widely used in many scientific fields including medicine, nanosciences and materials research. Considerable progress in recent years has been made in agronomic and plant science research thanks to X-ray CT technology. X-ray CT image-based phenotyping methods enable high-throughput and non-destructive measuring and inference of root systems, which makes downstream studies of complex mechanisms of plants during growth feasible. An impressive amount of plant CT scanning data has been collected, but how to analyze these data efficiently and accurately remains a challenge. We review statistical and computational approaches that have been or may be effective for the analysis of 3D CT images of plant roots. We describe and comment on different approaches to aspects of the analysis of plant roots based on images, namely, (1) root segmentation, i.e., the isolation of root from non-root matter; (2) root-system reconstruction; and (3) extraction of higher-level phenotypes. As many of these approaches are novel and have yet to be applied to this context, we limit ourselves to brief descriptions of the methodologies. With the rapid development and growing use of X-ray CT scanning technologies to generate large volumes of data relevant to root structure, it is timely to review existing and potential quantitative and computational approaches to the analysis of such data. Summaries of several computational tools are included in the Appendix.
      Citation: Agronomy
      PubDate: 2018-05-14
      DOI: 10.3390/agronomy8050071
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 72: Irrigation Water Quality and Soil Structural
           Stability: A Perspective with Some New Insights

    • Authors: Pichu Rengasamy
      First page: 72
      Abstract: The sustainability of irrigated agriculture depends on the quality of irrigation water used. The electrolyte concentration (EC) of irrigation water may lead to the accumulation of salts in the root zone layers and affect the physiological functions of the crop by osmotic and ion toxicity effects. Further, the cationic and anionic composition of the water may alter the exchangeable cation composition of the soil as well as its pH. Because of the dominance of sodium salts in many sources of irrigation water, parameters related to sodium such as exchangeable sodium percentage (ESP) of soils and sodium adsorption ratio (SAR) of soil solutions have been commonly used to study the effects of sodium in irrigation water on soil structural stability. Quirk and Schofield’s concept of ‘threshold electrolyte concentration’ (TEC) has shown the importance of electrolytes in preventing the effects of sodium on soil structure. Based on this concept, several models have been proposed to relate ESP or SAR with EC to predict the possible impacts of irrigation water on soil structural stability. However, many research reports indicate that this relationship varies with soils, and a given model is not suitable for all types of soils. Further, the effects of potassium and magnesium in the processes leading to clay dispersion are disregarded in these models. This essay analyses all the factors involved in the structural failure of soils with different cationic composition, identifies the defects in these TEC models, and re-defines TEC on the basis of new insights on dispersive and flocculating charges of soils. This review does not deal with EC effects on crops nor the role of contaminant ions not involved with soil structural stability.
      Citation: Agronomy
      PubDate: 2018-05-14
      DOI: 10.3390/agronomy8050072
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 73: Transdisciplinary Graduate Training in
           Predictive Plant Phenomics

    • Authors: Carolyn J. Lawrence-Dill, Theodore J. Heindel, Patrick S. Schnable, Stephanie J. Strong, Jill Wittrock, Mary E. Losch, Julie A. Dickerson
      First page: 73
      Abstract: Novel methods to increase crop productivity are required to meet anticipated demands for food, feed, fiber, and fuel. It is becoming feasible to use modern sensors and data analysis techniques for predicting plant growth and productivity based on genomic, phenotypic, and environmental data. To design and construct crops that deliver desired traits requires trained personnel with scientific and engineering expertise as well as a variety of “soft” skills. To address these needs at Iowa State University, we developed a graduate specialization called “Predictive Plant Phenomics” (P3). Although some of our experiences may be unique, many of the specialization’s principles are likely to be broadly applicable to others interested in developing graduate training programs in plant phenomics. P3 involves transdisciplinary training and activities designed to develop communication, teambuilding, and management skills. To support students in this demanding and unique intellectual environment, we established a two-week boot camp before their first semester and founded a community of practice to support students throughout their graduate careers. Assessments show that P3 students understand the transdisciplinary training concepts, have formed a beneficial and supportive community, and interact with diverse faculty outside of their home departments. To learn more about the P3 program, visit
      Citation: Agronomy
      PubDate: 2018-05-16
      DOI: 10.3390/agronomy8050073
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 74: Short-Term Effects of Biochar Amendment on
           Greenhouse Gas Emissions from Rainfed Agricultural Soils of the
           Semi–Arid Loess Plateau Region

    • Authors: Stephen Yeboah, Shirley Lamptey, Liqun Cai, Min Song
      First page: 74
      Abstract: In rainfed agricultural ecosystems in northwest China, improving soil fertility and reducing greenhouse gas (GHG) emissions are key factors for developing sustainable agriculture. This study determined the short-term effects of different biochar amendment rates on diurnal and seasonal variations of GHG emissions in the Loess Plateau to produce a background dataset that may be used to inform nutrient management guidelines for semiarid environments. Biochar produced by pyrolysis at 300–500 °C from maize straw was applied at rates of 0, 10, 20, 30, 40, and 50 t ha−1 (T0, T1, T2, T3, T4, T5), respectively. The results indicated that in the first year after the application, T3, T4, and T5 treatments increased soil organic carbon (0–10 cm) by 54.7%, 56.3%, and 56.9% compared to the other treatments. In the first, year, biochar amendment decreased diurnal CH4 and N2O flux by an average of 17–119% compared to T0, among which T3 had the lowest mean value. T3 and T4 also had similar mean CO2 flux, which was 33% lower than T0. Application of 30 t ha−1 biochar produced the lowest cumulative CO2 and N2O emissions of 2300 and 4.07 kg h−1, respectively. Biochar amendment showed no effect on grain yiel but reduced the global warming potential and GHG emission intensity by an average of 23% and 25%, respectively. The biochar application rate of 30 t ha−1 under the conditions of this study may be an appropriate rate for improving soil C sequestration and mitigation of GHG emissions in the first year after its application to soils on semi–arid Loess Plateau.
      Citation: Agronomy
      PubDate: 2018-05-16
      DOI: 10.3390/agronomy8050074
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 75: Extension of Aquaponic Water Use for NFT
           Baby-Leaf Production: Mizuna and Rocket Salad

    • Authors: Carlo Nicoletto, Carmelo Maucieri, Alex Mathis, Zala Schmautz, Tamas Komives, Paolo Sambo, Ranka Junge
      First page: 75
      Abstract: Aquaponics is a recirculating technology that combines aquaculture with hydroponics. It allows nutrients from fish waste to feed plants and thus saves water and nutrients. However, there is a mismatch between the nutrients provided by the fish waste and plant needs. Because of this, some nutrients, notably N, tend to accumulate in the aquaponic water (APW or AP water). The aim of this study was to investigate how APW, which is depleted of P and K but still rich in N, could be further utilized. APW was used in a mesocosm and compared with APW from the same source that had been supplemented with macro-nutrients (complemented AP water or CAPW) and a hydroponic control (HC). Mizuna (M) and rocket salad (R) were used as short-cycle vegetable crops in a NFT system. The results revealed that the low production potential of APW was mainly caused by the lack of P and K. If these were supplemented, the yields were comparable to those in the HC. M yield in CAPW was significantly higher than that of HC, probably due to biostimulant effects connected to the organic components in the water as a result of fish farming. Water type, cultivation density, and intercropping significantly influenced the qualitative characteristics of the crop in terms of antioxidant compounds and minerals. Nitrate content in vegetables was lower than European regulation limits. The extended use of APW is viable if the missing nutrients are supplemented; this could be a strategy to increase the efficiency of water and nitrogen use, while further reducing environmental impact.
      Citation: Agronomy
      PubDate: 2018-05-17
      DOI: 10.3390/agronomy8050075
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 76: Concepts and Misconceptions of Humic
           Substances as the Stable Part of Soil Organic Matter: A Review

    • Authors: Jörg Gerke
      First page: 76
      Abstract: In the last three decades, the concept of soil humic substances has been questioned in two main directions. Misinterpretations of CP MAS13C NMR spectroscopy led to the conclusion that soil organic matter is mainly aliphatic, questioning the theory of polymerization of humic substances from phenolic molecules. Conversely, some critics of humic substances assume that a great proportion of aromatic soil organic carbon originates from fire-affected carbon, often termed as black carbon (BC). However, the determination of BC in soil by two widely applied methods, the benzene polycarboxylic acid marker method and the UV method, is not reliable and seems to strongly overestimate the BC content of soils. The concept of humic substances continues to be relevant today. The polymerization of phenolic molecules that originate from the degradation of lignin or synthesis by microorganisms may lead to humic substances which can incorporate a variety of organic and inorganic molecules and elements. The incorporation, e.g., of triazines or surfactants into the humic matrix, leading to bound residues, illustrates that humic substances are important to explain central reactions in soil. Humic substances are also important to understand the availability of plant nutrients in soil, including P, Fe, and Cu, and they may have a direct effect on the growth of higher plants in soil. Therefore, there are good reasons to reformulate or to further develop the concepts and models of humic substances introduced and developed by M. Schnitzer, W. Flaig, W. Ziechmann, and F.J. Stevenson.
      Citation: Agronomy
      PubDate: 2018-05-17
      DOI: 10.3390/agronomy8050076
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 77: Efficient Callus Induction and Regeneration in
           Selected Indica Rice

    • Authors: Suraiya Binte Mostafiz, Alina Wagiran
      First page: 77
      Abstract: An efficient callus induction and in vitro regeneration were developed using plant growth regulators, carbon sources, and basal media for three selected Malaysian wetland rice varieties (MR220, MR220-CL2, and MR232) and one upland variety (Bario). Effect of plant growth regulator (PGR) was carried out using four different concentrations (1–4 mg/L) of 2,4-D (2, 4-dichlorophenoxyacetic acid), and NAA (1-naphthalene acetic acid) (2.5, 5.0, 7.5, and 10 mg/L) with optimized 2,4-D. Effects of carbon sources (maltose and sorbitol), and basal media (MS, N6, and LS) were also studied with optimized PGR to maximize the induction of regenerable calli. This study found that all four varieties exhibited high frequency of callus induction on MS (Murashige and Skoog) medium that was supplemented with 3 mg/L 2,4-D and 30 g/L maltose. Callus induction frequencies in the cases of MR220, MR220-CL2, MR232, and Bario were found to be 76%, 94%, 85%, and 42% respectively. Morphological analysis through scanning electron microscopy (SEM) and histological analysis revealed the embryogenicity of the induced callus. In the regeneration study, it was observed that combination of 2 mg/L BAP (6-benzylaminopurine), 2 mg/L Kin (Kinetin) and 0.5 mg/L NAA supplemented MS medium has the potential to promote regeneration of selected indica rice varieties with higher regeneration percentage, i.e., 82% (MR220-CL2), 68% (both in MR220 and MR232), and 40% (Bario). The optimized conditions for callus formation and regeneration can be useful for biotechnological practices for the genetic improvement of Malaysian indica rice.
      Citation: Agronomy
      PubDate: 2018-05-21
      DOI: 10.3390/agronomy8050077
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 78: Challenges in Using Precision Agriculture to
           Optimize Symbiotic Nitrogen Fixation in Legumes: Progress, Limitations,
           and Future Improvements Needed in Diagnostic Testing

    • Authors: Malinda S. Thilakarathna, Manish N. Raizada
      First page: 78
      Abstract: Precision agriculture (PA) has been used for ≥25 years to optimize inputs, maximize profit, and minimize negative environmental impacts. Legumes play an important role in cropping systems, by associating with rhizobia microbes that convert plant-unavailable atmospheric nitrogen into usable nitrogen through symbiotic nitrogen fixation (SNF). However, there can be field-level spatial variability for SNF activity, as well as underlying soil factors that influence SNF (e.g., macro/micronutrients, pH, and rhizobia). There is a need for PA tools that can diagnose spatial variability in SNF activity, as well as the relevant environmental factors that influence SNF. Little information is available in the literature concerning the potential of PA to diagnose/optimize SNF. Here, we critically analyze SNF/soil diagnostic methods that hold promise as PA tools in the short–medium term. We also review the challenges facing additional diagnostics currently used for research, and describe the innovations needed to move them forward as PA tools. Our analysis suggests that the nitrogen difference method, isotope methods, and proximal and remote sensing techniques hold promise for diagnosing field-level variability in SNF. With respect to soil diagnostics, soil sensors and remote sensing techniques for nitrogen, phosphorus, pH, and salinity have short–medium term potential to optimize legume SNF under field conditions.
      Citation: Agronomy
      PubDate: 2018-05-21
      DOI: 10.3390/agronomy8050078
      Issue No: Vol. 8, No. 5 (2018)
  • Agronomy, Vol. 8, Pages 33: Relationship of Melatonin and Salicylic Acid
           in Biotic/Abiotic Plant Stress Responses

    • Authors: Josefa Hernández-Ruiz, Marino Arnao
      First page: 33
      Abstract: Melatonin (N-acetyl-5-methoxytryptamine) was discovered in plants in 1995, while salicylic acid was the name given to the active ingredient of willow in 1838. From a physiological point of view, these two molecules present in plants have never been compared, even though they have a great number of similarities, as we shall see in this work. Both molecules have biosynthesis pathways that share a common precursor and both play a relevant role in the physiology of plants, especially in aspects related to biotic and abiotic stress. They have also been described as biostimulants of photosynthetic processes and productivity enhancers in agricultural crops. We review the coincident aspects of both molecules, and propose an action model, by which the relationship between these molecules and other agents and plant hormones can be studied.
      Citation: Agronomy
      PubDate: 2018-03-22
      DOI: 10.3390/agronomy8040033
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 34: Challenges and Responses to Ongoing and
           Projected Climate Change for Dryland Cereal Production Systems throughout
           the World

    • Authors: Garry O’Leary, Pramod Aggarwal, Daniel Calderini, David Connor, Peter Craufurd, Sanford Eigenbrode, Xue Han, Jerry Hatfield
      First page: 34
      Abstract: Since the introduction of mechanized production in both developed and developing countries, crops and their management have undergone significant adaptation resulting in increased productivity. Historical yield increases in wheat have occurred across most regions of the world (20–88 kg ha−1 year−1), but climate trends threaten to dampen or reverse these gains such that yields are expected to decrease by 5–6% despite rising atmospheric CO2 concentrations. Current and projected climatic factors are temporally and spatially variable in dryland cereal production systems throughout the world. Productivity gains in wheat in some locations have been achieved from traditional agronomic practices and breeding. Continued improvement in all cereal production regions and locations of the world requires technical advances, including closer monitoring of soils, water conservation strategies, and multiple sowing times using different crops to reduce risks. The management of disease, pests, and weeds will be an added challenge, especially in areas of higher precipitation. Excellent progress has been achieved in Asia and there is much potential in Sub-Saharan Africa. Technical solutions seem within our grasp but must be implemented in the context of variable social, economic, regulatory, and administrative constraints, providing opportunities for cross fertilization and global collaboration to meet them.
      Citation: Agronomy
      PubDate: 2018-03-23
      DOI: 10.3390/agronomy8040034
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 35: First Case of Glufosinate-Resistant Rigid
           Ryegrass (Lolium rigidum Gaud.) in Greece

    • Authors: Ilias Travlos, Nikolina Cheimona, Rafael De Prado, Amit Jhala, Demosthenis Chachalis, Eleni Tani
      First page: 35
      Abstract: Repeated applications of the same herbicide(s), which are characterized by the same mode of action, increase selection pressure, which in turn favours the evolution of herbicide-resistant weeds. Glufosinate is a broad-spectrum non-selective herbicide being used for weed control for many years around the world. Rigid ryegrass (Lolium rigidum Gaud.) is an economically important grass weed in Greece. Recent complaints by growers about control failure of rigid ryegrass with glufosinate require further investigation and have been the basis of this study. The objectives of this study were to confirm the existence of glufosinate-resistant L. rigidum in Greece and evaluate the effect of L. rigidum growth stage on glufosinate efficacy. Twenty populations of rigid ryegrass from Greece were sampled from five regions, and whole plant dose–response studies were conducted for five populations under controlled conditions with eight rates of glufosinate (0.0, 0.098, 0.187, 0.375, 0.75, 1.5, 3.0, and 6.0 kg a.i. ha−1). Glufosinate resistance was confirmed in three out of five populations with the level of resistance ranging from three-to seven-fold compared with the susceptible populations based on above-ground biomass reduction. Results also revealed that the level of glufosinate-resistance of rigid ryegrass was dependent on the growth stage at which it was applied.
      Citation: Agronomy
      PubDate: 2018-03-27
      DOI: 10.3390/agronomy8040035
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 36: Genome-Wide Identification of Insertion and
           Deletion Markers in Chinese Commercial Rice Cultivars, Based on
           Next-Generation Sequencing Data

    • Authors: Kesavan Markkandan, Seung-il Yoo, Young-Chan Cho, Dong Lee
      First page: 36
      Abstract: Rice, being a staple food crop for over one-third of the world’s population, has become a potential target for many dishonest traders and stakeholders for mixing with low-grade, low-cost grains/products and poorly nutritious adulterants to make a profit with the least effort. Single-nucleotide and insertion–deletion (InDel) polymorphisms have been widely used as DNA markers, not only in plant breeding but also to identify various traits in rice. Recently, next-generation sequencing (NGS) has produced sequences that allow for genome-wide detection of these molecular markers. These polymorphisms can potentially be used to develop high-accuracy polymerase chain reaction (PCR)-based markers. PCR-based techniques are rapid and successful methods to deal with the problem of adulteration at a commercial level. Here, we report the genome-wide analysis of InDel markers of 17 commercially available Chinese cultivars. In order to achieve accurate results, all samples were sequenced at approximately 30× genome coverage using Illumina HiSeq 2500™ system. An average of 10.6 GB clean reads per sample was produced and ~96.3% of the reads could be mapped to the rice genome reference IRGSP 1.0. After a series of filtering, we selected five InDel markers for PCR validation. The results revealed that these InDel markers can be used for authentication of Korean elite cultivars from the adulterants.
      Citation: Agronomy
      PubDate: 2018-03-27
      DOI: 10.3390/agronomy8040036
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 37: Performance and Stability of Commercial Wheat
           Cultivars under Terminal Heat Stress

    • Authors: Ibrahim Elbasyoni
      First page: 37
      Abstract: Egypt, the fifteenth most populated country and the largest wheat importer worldwide, is vulnerable to global warming. Ten of the commercial and widely grown wheat cultivars were planted in two locations, i.e., Elbostan and Elkhazan for three successive seasons 2014/2015, 2015/2016, and 2016/2017 under two sowing dates (recommended and late). Elbostan and Elkhazan are the two locations used in this study because they represent newly reclaimed sandy soil and the Nile delta soil (clay), respectively. A split-plot, with main plots arranged as a randomized complete block design and three replicates, was used. The overall objective of this study was to identify the ideal cultivar for recommended conditions and heat stressed conditions. The results revealed that heat stress had a significant adverse impact on all traits while it raised the prevalence and severity of leaf and stem rust which contributed to overall yield losses of about 40%. Stability measurements, the additive main effects and multiplicative interaction model (AMMI) and genotype main effect plus genotype × environment interaction (GGE), were useful to determine the ideal genotypes for recommended and late sowing conditions (heat stressed). However, inconsistency was observed among some of these measurements. Cultivar “Sids12” was stable and outperformed other tested cultivars under combined sowing dates across environments. However, cultivar “Gemmeiza9” was more stable and outperformed other cultivars across environments under the recommended sowing date. Moreover, cultivar “Gemmeiza12” was the ideal cultivar for the late sown condition. Based on our findings, importing and evaluating heat stress tolerant wheat genotypes under late sown conditions or heat stressed conditions in Egypt is required to boost heat stress tolerance in the adapted wheat cultivars.
      Citation: Agronomy
      PubDate: 2018-03-29
      DOI: 10.3390/agronomy8040037
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 38: Field Screening of Waterlogging Tolerance in
           Spring Wheat and Spring Barley

    • Authors: Tove Sundgren, Anne Uhlen, Wendy Waalen, Morten Lillemo
      First page: 38
      Abstract: Improved waterlogging tolerance of wheat and barley varieties may alleviate yield constraints caused by heavy or long-lasting precipitation. The waterlogging tolerance of 181 wheat and 210 barley genotypes was investigated in field trials between 2013 and 2014. A subset of wheat genotypes were selected for yield trials in 2015 and 2016. Our aim was to: (1) characterize the waterlogging tolerance of genotypes with importance for Norwegian wheat and barley breeding, and (2) identify which phenotypic traits that most accurately determine the waterlogging tolerance of wheat in our field trials. Waterlogging tolerance was determined by principal component analysis (PCA) where best linear unbiased predictors (BLUPs) of the traits chlorosis, relative plant height, heading delay, relative spike number, relative biomass and an overall condition score were used as input variables. Six wheat and five barley genotypes were identified as consistently more tolerant in 2013 and 2014. This included the waterlogging tolerant CIMMYT line CETA/Ae. tauschii (895). Chlorosis and the overall condition score were the traits that best explained the yield response of the genotypes selected for the yield trials. Our results show that early stress symptoms did not necessarily reflect the ability to recover post treatment. Thus, records from full crop cycles appear as fundamental when screening populations with unknown tolerance properties.
      Citation: Agronomy
      PubDate: 2018-03-29
      DOI: 10.3390/agronomy8040038
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 39: Barnyardgrass Root Recognition Behaviour for
           Rice Allelopathy

    • Authors: Tingshuang Zhang, Bo Fan, Peng Wang
      First page: 39
      Abstract: Recent studies have demonstrated that the presence of belowground neighbours induces varied morphological and biochemical responses in plants. Plant allelopathic activity is elicited by the presence of competitor seedlings or competitor root exudates. However, it is unknown whether allelopathy also influences root recognition behaviour in weed–crop interaction. To assess barnyardgrass response to the presence of allelopathic rice roots, we conducted a greenhouse experiment of barnyardgrass–rice mixed culture, including barnyardgrass monoculture, barnyardgrass mixed with the allelopathic rice line PI312777 and barnyardgrass mixed with the nonallelopathic rice cultivar Liaojing-9. Our results showed that the presence of allelopathic rice roots enhanced root allocation and tissue density (RTD) of barnyardgrass, whereas it decreased root biomass, total root length, specific root length (SRL) and topological index (TI), compared to barnyardgrass grown in monoculture; moreover, there was a significant correlation of topological index with root foraging precision and competition. Therefore, the presence of allelopathic rice roots affected the barnyardgrass root morphology, nutrient foraging and competition, suggesting that allelopathy plays a key role in root recognition behaviour of barnyardgrass–rice competitive interaction.
      Citation: Agronomy
      PubDate: 2018-03-29
      DOI: 10.3390/agronomy8040039
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 40: Generating Improved Experimental Designs with
           Spatially and Genetically Correlated Observations Using Mixed Models

    • Authors: Lazarus Mramba, Gary Peter, Vance Whitaker, Salvador Gezan
      First page: 40
      Abstract: The aim of this study was to generate and evaluate the efficiency of improved field experiments while simultaneously accounting for spatial correlations and different levels of genetic relatedness using a mixed models framework for orthogonal and non-orthogonal designs. Optimality criteria and a search algorithm were implemented to generate randomized complete block (RCB), incomplete block (IB), augmented block (AB) and unequally replicated (UR) designs. Several conditions were evaluated including size of the experiment, levels of heritability, and optimality criteria. For RCB designs with half-sib or full-sib families, the optimization procedure yielded important improvements under the presence of mild to strong spatial correlation levels and relatively low heritability values. Also, for these designs, improvements in terms of overall design efficiency (ODE%) reached values of up to 8.7%, but these gains varied depending on the evaluated conditions. In general, for all evaluated designs, higher ODE% values were achieved from genetically unrelated individuals compared to experiments with half-sib and full-sib families. As expected, accuracy of prediction of genetic values improved as levels of heritability and spatial correlations increased. This study has demonstrated that important improvements in design efficiency and prediction accuracies can be achieved by optimizing how the levels of a treatment are assigned to the experimental units.
      Citation: Agronomy
      PubDate: 2018-03-30
      DOI: 10.3390/agronomy8040040
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 41: Phosphorus and Nitrogen Yield Response Models
           for Dynamic Bio-Economic Optimization: An Empirical Approach

    • Authors: Matti Sihvonen, Kari Hyytiäinen, Elena Valkama, Eila Turtola
      First page: 41
      Abstract: Nitrogen (N) and phosphorus (P) are both essential plant nutrients. However, their joint response to plant growth is seldom described by models. This study provides an approach for modeling the joint impact of inorganic N and P fertilization on crop production, considering the P supplied by the soil, which was approximated using the soil test P (STP). We developed yield response models for Finnish spring barley crops (Hordeum vulgare L.) for clay and coarse-textured soils by using existing extensive experimental datasets and nonlinear estimation techniques. Model selection was based on iterative elimination from a wide diversity of plausible model formulations. The Cobb−Douglas type model specification, consisting of multiplicative elements, performed well against independent validation data, suggesting that the key relationships that determine crop responses are captured by the models. The estimated models were extended to dynamic economic optimization of fertilization inputs. According to the results, a fair STP level should be maintained on both coarse-textured soils (9.9 mg L−1 a−1) and clay soils (3.9 mg L−1 a−1). For coarse soils, a higher steady-state P fertilization rate is required (21.7 kg ha−1 a−1) compared with clay soils (6.75 kg ha−1 a−1). The steady-state N fertilization rate was slightly higher for clay soils (102.4 kg ha−1 a−1) than for coarse soils (95.8 kg ha−1 a−1). This study shows that the iterative elimination of plausible functional forms is a suitable method for reducing the effects of structural uncertainty on model output and optimal fertilization decisions.
      Citation: Agronomy
      PubDate: 2018-03-31
      DOI: 10.3390/agronomy8040041
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 42: Assessing Field Prunus Genotypes for Drought
           Responsive Potential by Carbon Isotope Discrimination and Promoter

    • Authors: Beatriz Bielsa, Carole Bassett, D. Michael Glenn, María José Rubio-Cabetas
      First page: 42
      Abstract: In order to improve the effectiveness of breeding practices for Prunus rootstocks, it is essential to obtain new resistance resources, especially with regard to drought. In this study, a collection of field-grown Prunus genotypes, both wild-relative species and cultivated hybrid rootstocks, were subjected to leaf ash and carbon isotope discrimination (Δ13C) analyses, which are strongly correlated to water use efficiency (WUE). Almond and peach wild relative species showed the lowest Δ13C ratios, and therefore, the highest WUE in comparison with hybrid genotypes. In addition, drought-related cis-regulatory elements (CREs) were identified in the promoter regions of the effector gene PpDhn2, and the transcription factor gene DREB2B, two genes involved in drought-response signaling pathways. The phylogenetic analysis of these regions revealed variability in the promoter region sequences of both genes. This finding provides evidence of genetic diversity between the peach- and almond-relative individuals. The results presented here can be used to select Prunus genotypes with the best drought resistance potential for breeding.
      Citation: Agronomy
      PubDate: 2018-04-05
      DOI: 10.3390/agronomy8040042
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 43: Assessing Olive Evapotranspiration
           Partitioning from Soil Water Balance and Radiometric Soil and Canopy

    • Authors: Francisco Santos
      First page: 43
      Abstract: Evapotranspiration (ETc) partitioning and obtaining of FAO56 dual crop coefficient (Kc) for olive was carried out with the SIMDualKc software application for root zone and topsoil soil water balance based on the dual crop coefficients. A simplified two source-energy balance model (STSEB), based on daily remotely sensed soil and canopy thermal infrared data and retrieval of surface fluxes, also provided information on partitioning ETc for the olive orchard. Both models were calibrated and validated with ground-based, sap flow-derived transpiration rates, and their performance was compared in partitioning ETc for incomplete cover, intensive olive grown in orchards (≤300 trees ha−1). The SIMDualKc proved adequate in partitioning ETc. The STSEB model underestimated ETc mostly by inadequately simulating soil evaporation and its contribution to the total latent heat flux. Such results suggest difficulties in using information from the STSEB algorithm for assessing ETc and dual Kc crop coefficients of intensive olive orchards with incomplete ground cover.
      Citation: Agronomy
      PubDate: 2018-04-06
      DOI: 10.3390/agronomy8040043
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 44: Physiological Response of Wheat to Chemical
           Desiccants Used to Simulate Post-Anthesis Drought Stress

    • Authors: Nasrein Kamal, Yasir Gorafi, Ryosuke Mega, Hisashi Tsujimoto
      First page: 44
      Abstract: Post-anthesis drought stress is one of the main constraints on the production of wheat (Triticum aestivum L.). Because field screening for post-anthesis drought tolerance is difficult, effective and validated methods to simulate drought in order to identify sources of tolerance can facilitate screening of breeding materials. Chemical desiccants are widely used to simulate post-anthesis drought stress. We aimed to identify physiological traits that respond to desiccants as they do to drought. We examined the responses of ‘Norin 61’ to six treatments in a greenhouse: irrigated control, drought after anthesis, and 2% or 4% potassium chlorate (KClO3) at anthesis (A) or grain filling (GF). We measured δ13C in leaves, aboveground fresh biomass, stomatal conductance, chlorophyll content, harvest index, and grain yield. Both 2% and 4% KClO3 at both A and GF simulated the effect of drought stress. Selection of drought-tolerant genotypes can be aided by chlorophyll content and δ13C measurement of leaves when 2% or 4% KClO3 is used to simulate drought.
      Citation: Agronomy
      PubDate: 2018-04-09
      DOI: 10.3390/agronomy8040044
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 45: Metabolic Profiling of Phloem Exudates as a
           Tool to Improve Bread-Wheat Cultivars

    • Authors: S. Basile, Mike Burrell, Heather Walker, Jorge Cardozo, Chloe Steels, Felix Kallenberg, Jorge Tognetti, Horacio DallaValle, W. Rogers
      First page: 45
      Abstract: In a proof of concept study aimed at showing that metabolites in bread wheat (Triticum aestivum L. ssp. aestivum), phloem exudates have potential as biochemical markers for cultivar discrimination, Argentinean cultivars from three quality groups (groups 1, 2, and 3 of high, intermediate, and low quality, respectively) were grown under two nitrogen (N) availabilities and analysed for metabolic profile by electrospray ionisation mass spectrometry. Data as signal strengths of mass/charge (m/z) values binned to a resolution of 0.2 Daltons were subjected to principal component analysis and orthogonal projections to latent structures discriminant analysis. Certain bins were influential in discriminating groups taken in pairs and some were involved in separating all three groups. In high N availability, group 3 cultivars clustered away from the other cultivars, while group 1 cultivars clustered tightly together; group 2 cultivars were more scattered between group 1 and group 3 cultivars. In low N availability, the cultivars were not clustered as tightly; nonetheless, group 1 cultivars tended to cluster together and mainly separated from those of group 2. m/z values also showed potential for discrimination between N availability. In conclusion, phloem exudate metabolic profiles could provide biochemical markers for selection during breeding and for discerning the effects of N fertiliser application.
      Citation: Agronomy
      PubDate: 2018-04-10
      DOI: 10.3390/agronomy8040045
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 46: Molecular Cloning and Structure–Function
           Analysis of a Trypsin Inhibitor from Tartary Buckwheat and Its Application
           in Combating Phytopathogenic Fungi

    • Authors: Jing-jun Ruan, Shan-jun Tian, Jun Yan, Hui Chen, Ru-hong Xu, Jian-ping Cheng
      First page: 46
      Abstract: Host plant protease inhibitors offer resistance to proteases from invading pathogens. Trypsin inhibitors (TIs), in particular, serve as protective agents against insect and pathogen attacks. In this study, we designed a pair of degenerate primers based on highly conserved motifs at the N- and C-termini of the TI from tartary buckwheat (Fagopyrum tataricum; Ft) to clone the central portion. Genomic walking was performed to isolate the 5′ and 3′ flanking regions of FtTI. We demonstrated the successful PCR amplification of a 644 bp portion of FtTI. The full-length DNA of FtTI contains a complete open reading frame of 264 bp, encoding 87 amino acids with a mass of approximately 9.5 kDa. The FtTI protein sequence was 49% identical and 67% similar to potato protease inhibitors. Site-directed mutagenesis identified the residues, Asp67 and Arg68, as crucial for the inhibitory activity of the FtTI. Recombinant and mutant FtTI inhibited both the hyphal growth and spore germination of Alternaria solani. The calculated 50% inhibitory concentrations of FtTI ranged from 5–100 μg mL−1 for spore germination and 1–50 μg mL−1 for fungal growth. Thus, recombinant FtTI may function in host resistance against a variety of fungal plant pathogens.
      Citation: Agronomy
      PubDate: 2018-04-12
      DOI: 10.3390/agronomy8040046
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 47: Genetic Diversity of Diurnal Carbohydrate
           Accumulation in White Clover (Trifolium repens L.)

    • Authors: Michael E. Ruckle, Lucia Bernasconi, Roland Kölliker, Samuel C. Zeeman, Bruno Studer
      First page: 47
      Abstract: White clover (Trifolium repens L.) is one of the most important legumes for fodder production in temperate climates, particularly in intensive pasture systems. Like many other forage legumes, it lacks the energy content to maximize productivity of modern ruminant livestock breeds. White clover produces water-soluble carbohydrates and starch in its leaves as a diurnal product of photosynthesis. However, little is known about the genetically encoded variability of diel changes in carbohydrate content. We assessed the amount of glucose, fructose, sucrose, and starch in the leaves of 185 plants of a genetically diverse white clover population. Water-soluble carbohydrates only provided on average 10.6% of dry weight (DW) of the total analyzed non-structural carbohydrate (NSC) content at the end of the day (ED), while starch supplied 89.4% of the NSC content. The top 5% of individuals accumulated over 25% of their DW as starch at ED. The leaf starch content at ED showed up to a threefold difference between genotypes, with a repeatability value of 0.95. Our experiments illustrate both the physical potential of white clover to serve as a competitive energy source to meet the demand of modern ruminant livestock production and the genetic potential to improve this trait by breeding.
      Citation: Agronomy
      PubDate: 2018-04-13
      DOI: 10.3390/agronomy8040047
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 48: Are Nitrogen Fertilizers Deleterious to Soil

    • Authors: Bijay- Singh
      First page: 48
      Abstract: Soil is one of the most important natural resources and medium for plant growth. Anthropogenic interventions such as tillage, irrigation, and fertilizer application can affect the health of the soil. Use of fertilizer nitrogen (N) for crop production influences soil health primarily through changes in organic matter content, microbial life, and acidity in the soil. Soil organic matter (SOM) constitutes the storehouse of soil N. Studies with 15N-labelled fertilizers show that in a cropping season, plants take more N from the soil than from the fertilizer. A large number of long-term field experiments prove that optimum fertilizer N application to crops neither resulted in loss of organic matter nor adversely affected microbial activity in the soil. Fertilizer N, when applied at or below the level at which maximum yields are achieved, resulted in the build-up of SOM and microbial biomass by promoting plant growth and increasing the amount of litter and root biomass added to soil. Only when fertilizer N was applied at rates more than the optimum, increased residual inorganic N accelerated the loss of SOM through its mineralization. Soil microbial life was also adversely affected at very high fertilizers rates. Optimum fertilizer use on agricultural crops reduces soil erosion but repeated application of high fertilizer N doses may lead to soil acidity, a negative soil health trait. Site-specific management strategies based on principles of synchronization of N demand by crops with N supply from all sources including soil and fertilizer could ensure high yields, along with maintenance of soil health. Balanced application of different nutrients and integrated nutrient management based on organic manures and mineral fertilizers also contributed to soil health maintenance and improvement. Thus, fertilizer N, when applied as per the need of the field crops in a balanced proportion with other nutrients and along with organic manures, if available with the farmer, maintains or improves soil health rather than being deleterious.
      Citation: Agronomy
      PubDate: 2018-04-14
      DOI: 10.3390/agronomy8040048
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 49: Maize (Zea mays L.) Response to Secondary and
           Micronutrients for Profitable N, P and K Fertilizer Use in Poorly
           Responsive Soils

    • Authors: Ruth Njoroge, Abigael N. Otinga, John R. Okalebo, Mary Pepela, Roel Merckx
      First page: 49
      Abstract: Deficiencies of secondary and micronutrients (SMNs) are major causes of low maize yields in poorly responsive soils. This phenomenon minimizes the agronomic efficiency of N, P and K fertilizers and consequently result in a dwindling economic benefit associated with their use. Therefore, 18 on-farm trials were conducted in western Kenya during two cropping seasons to assess maize response to three NPK amendments; (i) N, P, K, Ca, Zn and Cu (inorganic and organic); (ii) N, P, K, Ca, Zn and Cu (inorganic) and (iii) N, P K, Zn and Cu (inorganic) and evaluate the profitability of their use compared to additions of only N, P and K fertilizers. In this set of experiments, maize response to any amendment refers to a yield increase of ≥2 t ha−1 above control and could be categorized in three clusters. Cluster 1, comprising of nine sites, maize responded to all amendments. Cluster 2, holding six sites, maize responded only to one amendment, N, P, K, Ca, Zn and Cu (inorganic). In this cluster, (2), emerging S, Mg and Cu deficiencies may still limit maize production. Cluster 3; consisting of three sites, maize responded poorly to all amendments due to relatively high soil fertility (≥17 mg P kg−1). Profitability of using NPK amendments is limited to Cluster 1 and 2 and the largest Value Cost Ratio (VCR) of 3.1 is attainable only when soil available P is below 4.72 mg kg−1. These variable responses indicate the need for developing site-specific fertilizer recommendations for improved maize production and profitability of fertilizer use in poorly responsive soils.
      Citation: Agronomy
      PubDate: 2018-04-15
      DOI: 10.3390/agronomy8040049
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 50: Physiological and Biochemical Characterization
           of a Red Escarole Obtained from an Interspecies Crossing

    • Authors: Alessandro Natalini, Giacomo Cocetta, Nazzareno Acciarri, Antonio Ferrante
      First page: 50
      Abstract: Escarole (Cichorium endivia L.) and radicchio (Cichorium intybus L.) are two important leafy vegetables appreciated by consumers for their sensory attributes, and at the same time, they can be considered a good source of health-promoting secondary metabolites, including polyphenols, flavonoids, and anthocyanins. The aim of this work is the characterization of a new variety of red escarole obtained after a long-term breeding program involving the interspecies crossing between red radicchio and green escarole. Our multidisciplinary approach of investigation allowed us to study the effects of the crossing on several aspects, including the accumulation of phenolic compounds and anthocyanins, the expression pattern of some of the key genes in the phenylpropanoid pathway, and the sensory profiling of the new variety obtained. Given the results, it is possible to conclude that the new variety of red escarole presents traits deriving from both radicchio and escarole. The sensory profile and the preliminary data on yield, suggests that red escarole has interesting characteristics that could be successfully introduced into the market of leafy crops.
      Citation: Agronomy
      PubDate: 2018-04-16
      DOI: 10.3390/agronomy8040050
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 51: Increasing Predictive Ability by Modeling
           Interactions between Environments, Genotype and Canopy Coverage Image Data
           for Soybeans

    • Authors: Diego Jarquin, Reka Howard, Alencar Xavier, Sruti Das Choudhury
      First page: 51
      Abstract: Phenomics is a new area that offers numerous opportunities for its applicability in plant breeding. One possibility is to exploit this type of information obtained from early stages of the growing season by combining it with genomic data. This opens an avenue that can be capitalized by improving the predictive ability of the common prediction models used for genomic prediction. Imagery (canopy coverage) data recorded between days 14–71 using two collection methods (ground information in 2013 and 2014; aerial information in 2014 and 2015) on a soybean nested association mapping population (SoyNAM) was used to calibrate the prediction models together with the inclusion of several types of interactions between canopy coverage data, environments, and genomic data. Three different scenarios were considered that breeders might face testing lines in fields: (i) incomplete field trials (CV2); (ii) newly developed lines (CV1); and (iii) predicting lines in unobserved environments (CV0). Two different traits were evaluated in this study: yield and days to maturity (DTM). Results showed improvements in the predictive ability for yield with respect to those models that solely included genomic data. These relative improvements ranged 27–123%, 27–148%, and 65–165% for CV2, CV1, and CV0, respectively. No major changes were observed for DTM. Similar improvements were observed for both traits when the reduced canopy information for days 14–33 was used to build the training-testing relationships, showing a clear advantage of using phenomics in very early stages of the growing season.
      Citation: Agronomy
      PubDate: 2018-04-17
      DOI: 10.3390/agronomy8040051
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 52: Agronomic and Economic Benefits of Pea/Maize
           Intercropping Systems in Relation to N Fertilizer and Maize Density

    • Authors: Caihong Yang, Zhilong Fan, Qiang Chai
      First page: 52
      Abstract: Intercropping has been shown to increase crop yields and improve land utilization in many cases but it is unknown how the interspecies relationship is enhanced with improved crop management schemes. In this study, we investigated the effect of different maize densities and N rates on the growth, crop yields and economic benefits of pea (Pisum sativum L.)/maize (Zea mays L.) intercropping. The results indicated that total yields of pea/maize intercropping were higher than the yield of maize alone, and that pea/maize intercropping improved land use efficiency significantly compared to sole crops, the partial land equivalent ratio (LER) of maize and pea with high planting density increased from 0.98% to 9.36% compared to low planting densities during 2012 and 2013. The pea strips provided significant compensatory effects on the growing maize after the earlier-sown, shorter-seasoned pea was harvested. The crop growth rate (CGR) of the intercropped maize was 18.5% to 216.9% greater than that of sole maize after pea harvest, the leaf area index (LAI) of pea/maize intercropping was 6.9% and 45.4% greater compared with the weighted average of sole maize and sole pea in 2012 and 2013, respectively. Net returns and benefit to cost ratios of pea/maize intercropping were increased with an increase of maize planting density. A low rate of N fertilizer was coupled with increased maize plant density, allowing interspecific facilitation to be fully expressed, thus improving the land utilization rate and increasing economic benefits. Overall, our findings show that a higher density of maize and lower N application can be used to increase grain production with no adverse effects on the growth components of either pea or maize crops. It could be considered an advanced farming system for agricultural sustainable development in the oasis region of northwest China.
      Citation: Agronomy
      PubDate: 2018-04-18
      DOI: 10.3390/agronomy8040052
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 53: Effect of the Slow-Release Nitrogen Fertilizer
           Oxamide on Ammonia Volatilization and Nitrogen Use Efficiency in Paddy

    • Authors: Ying Tang, Xun Li, Wenzhong Shen, Zengqiang Duan
      First page: 53
      Abstract: The effects of a single basal fertilization with oxamide compared with those of a split application of urea on ammonia volatilization, rice yield, nitrogen (N) accumulation, and N use efficiency were investigated in a field experiment over 2 years. The study consisted of two N fertilizers (oxamide and urea) applied at 157.5 and 225 kg N ha−1 and a no-N Control. Compared with urea, the single application of oxamide produced similar rice yields and reduced approximately 38.3% to 62.7% of the N lost through ammonia volatilization in 2013 and 2014. Oxamide applied at a rate of 225 kg N ha−1 resulted in greater aboveground accumulation of N by rice than the other treatments in both years, and oxamide fertilization resulted in the accumulation of an additional 15.2 kg N ha−1 and 15.3 kg N ha−1 compared to the amounts accumulated under the urea treatments at the same N application rates. N use efficiency was higher under oxamide than under urea treatment. In conclusion, the use of oxamide as a fertilizer can reduce N loss via ammonia volatilization, increase N use efficiency, and maintain a steady rice grain yield.
      Citation: Agronomy
      PubDate: 2018-04-18
      DOI: 10.3390/agronomy8040053
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 54: Chitosan Coating: A Postharvest Treatment to
           Delay Oxidative Stress in Loquat Fruits during Cold Storage

    • Authors: Giuseppina Adiletta, Maria Silvia Pasquariello, Luigi Zampella, Francesco Mastrobuoni, Marco Scortichini, Milena Petriccione
      First page: 54
      Abstract: Loquat is a non-climacteric fruit consumed fresh for its essential nutrients and phytochemical compounds. In this study, the effects of chitosan coating (1% w/v) on changes in the enzymatic antioxidant and membrane damage in three loquat selections (CREAFRC-S18; CREAFRC-S35 and CREAFRC-S36) and three loquat cultivars (Golden Nugget, Algerie and Nespolone rosso di Trabia) stored at 7 °C over 21 days were evaluated. Chitosan treatment enhanced the activities of superoxide dismutase, catalase and ascorbate peroxidase. Moreover, this treatment inhibited polyphenol oxidase and guaiacol peroxidase activities, extending the storage life of loquat. Chitosan also preserved membrane integrity by inhibiting lipoxygenase activity and malondialdehyde accumulation. Principal component analysis provided a global view of the responses of both loquat selections and cultivars to the postharvest chitosan coating and storage temperature. These findings suggest that chitosan treatment could be a valid tool for improving the activity of antioxidant enzymes, preserving the enzymatic browning of loquat fruits.
      Citation: Agronomy
      PubDate: 2018-04-19
      DOI: 10.3390/agronomy8040054
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 55: Assessment of Genetic Diversity in Opuntia
           spp. Portuguese Populations Using SSR Molecular Markers

    • Authors: Carlos M. G. Reis, Joana Raimundo, Maria Margarida Ribeiro
      First page: 55
      Abstract: The Opuntia spp., most likely few individuals, were introduced in the Iberian Peninsula in the beginning of the 16th century, after the discovery of America, spreading afterwards throughout the Mediterranean basin. We analysed, for the first time, the genetic diversity in a set of 19 Portuguese Opuntia spp. populations from the species O. ficus-indica, O. elata, O. dillenii and O. robusta using nuclear microsatellite (nuSSR) markers. The Italian cultivars ‘Bianca’, ‘Gialla’ and ‘Rossa’ were included in the study for comparison purposes. The nuSSR amplifications produced from five to 16 alleles, with an average of 9.2 alleles per primer pair, and average polymorphism information content of 0.71. The estimated Dice coefficient among populations varied from 0.26 to 1.0, indicating high interspecific genetic diversity but low genetic diversity at the intraspecific level. The hierarchical clustering analysis revealed four major groups that clearly separated the four Opuntia species. Among the O. ficus-indica populations, two sub-clusters were found, one including the white pulp fruits (with cv. Bianca) and the other with the orange pulp ones and including the cv. Gialla, the cv. Rossa, and one pale yellow pulp population. No genetic differences were found between the inermis form, O. ficus-indica f. ficus-indica, and the rewilded spiny one, O. ficus-indica f. amyclaea. The dendrogram indicated that the clustering pattern was unrelated to geographical origin. The results revealed a low level of genetic diversity among the Portuguese populations of O. ficus-indica.
      Citation: Agronomy
      PubDate: 2018-04-20
      DOI: 10.3390/agronomy8040055
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 56: The Effect of Community-Based Soil and Water
           Conservation Practices on Abundance and Diversity of Soil
           Macroinvertebrates in the Northern Highlands of Ethiopia

    • Authors: Mengistu Welemariam, Fassil Kebede, Bobe Bedadi, Emiru Birhane
      First page: 56
      Abstract: Soil and water conservation (SWC) practices in the northern highlands of Ethiopia have important implications for land restoration and biodiversity recovery. The present study determined soil macroinvertebrate (SMI) abundance and diversity in response to spatial conditions i.e., generated by different conservation practices, soil depth, and temporal seasonality with the wet and dry season. The SWC practices considered were exclosure + terrace, exclosure alone, terraces, and non-conserved grazing lands. Each SWC measure was selected in three sites that were considered as replications due to low heterogeneity in terms of human and livestock disturbances and biophysical factors. Soil macroinvertebrates were collected using a monolith according to tropical soil biology and fertility (TSBF) method. The highest density (55%) of SMI was found in exclosures followed by terraces 26%. Non-conserved communal grazing lands account for only 19% of the total. Shannon diversity index was significantly (P < 0.05) higher (1.21) in the exclosures supported with terraces and the lowest (0.9) was observed in the non-conserved communal grazing lands. Diversity was also significantly (P < 0.05) higher (1.26) in wet than dry season (0.70). The highest (41%) Sorensen similarity index among SMI was found between exclosures with terraces and exclosures alone during the wet season. The lowest (20%) Sorensen similarity index was found between terraces alone and exclosures with terraces in dry season. Soil macroinvertebrate abundance was higher in upper (0–10 cm) than lower (10–20 and 20–30 cm) soil depth. Soil macroinvertebrate abundance was positively and strongly correlated with soil moisture (R2 = 0.85) and soil organic carbon stock (R2 = 0.95). However, it was negatively (R2 = −0.71) correlated with bulk density. Generally, the abundance and diversity of SMI increased as exclosures and communal grazing lands are supported with terraces.
      Citation: Agronomy
      PubDate: 2018-04-22
      DOI: 10.3390/agronomy8040056
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 57: Sensing Technologies for Precision Phenotyping
           in Vegetable Crops: Current Status and Future Challenges

    • Authors: Pasquale Tripodi, Daniele Massa, Accursio Venezia, Teodoro Cardi
      First page: 57
      Abstract: Increasing the ability to investigate plant functions and structure through non-invasive methods with high accuracy has become a major target in plant breeding and precision agriculture. Emerging approaches in plant phenotyping play a key role in unraveling quantitative traits responsible for growth, production, quality, and resistance to various stresses. Beyond fully automatic phenotyping systems, several promising technologies can help accurately characterize a wide range of plant traits at affordable costs and with high-throughput. In this review, we revisit the principles of proximal and remote sensing, describing the application of non-invasive devices for precision phenotyping applied to the protected horticulture. Potentiality and constraints of big data management and integration with “omics” disciplines will also be discussed.
      Citation: Agronomy
      PubDate: 2018-04-22
      DOI: 10.3390/agronomy8040057
      Issue No: Vol. 8, No. 4 (2018)
  • Agronomy, Vol. 8, Pages 25: Climate Change Trends and Impacts on
           California Agriculture: A Detailed Review

    • Authors: Tapan Pathak, Mahesh Maskey, Jeffery Dahlberg, Faith Kearns, Khaled Bali, Daniele Zaccaria
      First page: 25
      Abstract: California is a global leader in the agricultural sector and produces more than 400 types of commodities. The state produces over a third of the country’s vegetables and two-thirds of its fruits and nuts. Despite being highly productive, current and future climate change poses many challenges to the agricultural sector. This paper provides a summary of the current state of knowledge on historical and future trends in climate and their impacts on California agriculture. We present a synthesis of climate change impacts on California agriculture in the context of: (1) historic trends and projected changes in temperature, precipitation, snowpack, heat waves, drought, and flood events; and (2) consequent impacts on crop yields, chill hours, pests and diseases, and agricultural vulnerability to climate risks. Finally, we highlight important findings and directions for future research and implementation. The detailed review presented in this paper provides sufficient evidence that the climate in California has changed significantly and is expected to continue changing in the future, and justifies the urgency and importance of enhancing the adaptive capacity of agriculture and reducing vulnerability to climate change. Since agriculture in California is very diverse and each crop responds to climate differently, climate adaptation research should be locally focused along with effective stakeholder engagement and systematic outreach efforts for effective adoption and implementation. The expected readership of this paper includes local stakeholders, researchers, state and national agencies, and international communities interested in learning about climate change and California’s agriculture.
      Citation: Agronomy
      PubDate: 2018-02-26
      DOI: 10.3390/agronomy8030025
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 26: The Impact of Genetic Changes during Crop
           Domestication on Healthy Food Development

    • Authors: Petr Smýkal, Matthew Nelson, Jens Berger, Eric von Wettberg
      First page: 26
      Abstract: n/a
      Citation: Agronomy
      PubDate: 2018-03-07
      DOI: 10.3390/agronomy8030026
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 27: Nutrient Management in Aquaponics: Comparison
           of Three Approaches for Cultivating Lettuce, Mint and Mushroom Herb

    • Authors: Valentina Nozzi, Andreas Graber, Zala Schmautz, Alex Mathis, Ranka Junge
      First page: 27
      Abstract: Nutrients that are contained in aquaculture effluent may not supply sufficient levels of nutrients for proper plant development and growth in hydroponics; therefore, they need to be supplemented. To determine the required level of supplementation, three identical aquaponic systems (A, B, and C) and one hydroponic system (D) were stocked with lettuce, mint, and mushroom herbs. The aquaponic systems were stocked with Nile tilapia. System A only received nutrients derived from fish feed; system B received nutrients from fish feed as well as weekly supplements of micronutrients and Fe; system C received the same nutrients as B, with weekly supplements of the macronutrients, P and K; in system D, a hydroponic inorganic solution containing N, Ca, and the same nutrients as system C was added weekly. Lettuce achieved the highest yields in system C, mint in system B, and mushroom herb in systems A and B. The present study demonstrated that the nutritional requirements of the mint and mushroom herb make them suitable for aquaponic farming because they require low levels of supplement addition, and hence little management effort, resulting in minimal cost increases. While the addition of supplements accelerated the lettuce growth (Systems B, C), and even surpassed the growth in hydroponic (System C vs. D), the nutritional quality (polyphenols, nitrate content) was better without supplementation.
      Citation: Agronomy
      PubDate: 2018-03-07
      DOI: 10.3390/agronomy8030027
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 28: Different Approaches to Produce Transgenic
           Virus B Resistant Chrysanthemum

    • Authors: Tatiana Mitiouchkina, Aleksey Firsov, Svetlana Titova, Alexander Pushin, Olga Shulga, Sergey Dolgov
      First page: 28
      Abstract: Chrysanthemum is a vegetative propagated culture in which viral transmission with planting material is important for its production. Chrysanthemum virus B (CVB) belongs to the viruses that strike this plant culture. Chrysanthemum virus B is found everywhere where chrysanthemum is cultivated. Damage to plants by CVB often leads to a complete loss of floral yield. Chrysanthemum (Chrysanthemum morifolium Ramat cv. White Snowdon) was transformed via Agrobacterium-mediated DNA delivery with the aim of improving resistance to CVB infection. Transformation vectors contain the nucleotide sequence of CVB coat proteins (CP) in sense, antisense, and double sense orientation. The transformative vectors also invert repeats of CVB coat protein gene fragments for the induction of RNA-interference. The transgenic chrysanthemum plants were successfully obtained. The integration of the target sequences in plant genomes was confirmed by polymerase chain reaction (PCR) and Southern blot analyses. Chrysanthemum lines were transformed with antisense, sense, and double sense CVB CP sequences, as well as with hairpin RNA-interference constructs that were assayed for resistance to CVB. Infection of transgenic plants by CVB through the grafting of infected scions shows resistance only among plants with carried double sense (16.7%) and hairpin (12.5%) constructs. The plants transformed by sense and double sense sequences were observed and classified as tolerant.
      Citation: Agronomy
      PubDate: 2018-03-08
      DOI: 10.3390/agronomy8030028
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 29: Validation of a Process-Based Agro-Ecosystem
           Model (Agro-IBIS) for Maize in Xinjiang, Northwest China

    • Authors: Tureniguli Amuti, Geping Luo, Gang Yin, Qi Hu, E. Walter-Shea
      First page: 29
      Abstract: Agricultural oasis expansion and intensive management practices have occurred in arid and semiarid regions of China during the last few decades. Accordingly, regional carbon and water budgets have been profoundly impacted by agroecosystems in these regions. Therefore, study on the methods used to accurately estimate energy, water, and carbon exchanges is becoming increasingly important. Process-based models can represent the complex processes between land and atmosphere among agricultural ecosystems. However, before the models can be applied they must be validated under different environmental and climatic conditions. In this study, a process-based agricultural ecosystem model (Agro-IBIS) was validated for maize crops using 3 years of soil and biometric measurements at Wulanwusu agrometeorological site (WAS) located in the Shihezi oasis in Xinjiang, northwest China. The model satisfactorily represented leaf area index (LAI) during the growing season, simulating its peak values within the magnitude of 0–10%. The total biomass carbon was overestimated by 15%, 8%, and 16% in 2004, 2005, and 2006, respectively. The model satisfactorily simulated the soil temperature (0–10 cm) and volumetric water content (VWC) (0–25 cm) of farmland during the growing season. However, it overestimated soil temperature approximately by 4 °C and VWC by 15–30% during the winter, coinciding with the period of no vegetation cover in Xinjiang. Overall, the results indicate that the model could represent crop growth, and seems to be applicable in multiple sites in arid oases agroecosystems of Xinjiang. Future application of the model will impose more comprehensive validation using eddy covariance flux data, and consider including dynamics of crop residue and improving characterization of the final stage of leaf development.
      Citation: Agronomy
      PubDate: 2018-03-10
      DOI: 10.3390/agronomy8030029
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 30: Effect of Repeated Application of Manure on
           Herbage Yield, Quality and Wintering Ability during Cropping of Dwarf
           Napiergrass with Italian Ryegrass in Hilly Southern Kyushu, Japan

    • Authors: Renny Utamy, Yasuyuki Ishii, Sachiko Idota, Lizah Khairani
      First page: 30
      Abstract: The effects of two levels of manure application (184 and 275 kg N ha−1 year−1) on herbage yield, quality, and wintering ability during the cropping of a dwarf genotype of late-heading (DL) Napiergrass (Pennisetum purpureum Schumach) oversown with Italian ryegrass (IR; Lolium multiflorum Lam.) were examined and compared with chemical fertilizer application (234 kg N ha−1 year−1) for 4 years to determine a sustainable and environmentally harmonized herbage production in a hilly area (340 m above sea level). No significant (p > 0.05) differences in growth attributes of plant height, tiller density, percentage of leaf blade, or dry matter yield appeared in either DL Napiergrass or IR among moderate levels (184–275 kg N ha−1 year−1) of manure and chemical fertilizer treatments. IR exhibited no significant detrimental effect on spring regrowth of DL Napiergrass, which showed a high wintering ability in all treatments. In vitro dry matter digestibility of DL Napiergrass tended to increase with increasing manure application, especially at the first defoliation in the first three years. Manure application improved soil chemical properties and total nitrogen and carbon content. The results suggested that the lower rate of manure application of 184 kg nitrogen ha−1 year−1 would be suitable, which would be a good substitute for chemical fertilizer application with an equilibrium nitrogen budget for sustainable DL Napiergrass and IR cropping in the hilly region of southern Kyushu.
      Citation: Agronomy
      PubDate: 2018-03-10
      DOI: 10.3390/agronomy8030030
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 31: Potassium: A Vital Regulator of Plant
           Responses and Tolerance to Abiotic Stresses

    • Authors: Mirza Hasanuzzaman, M. Bhuyan, Kamrun Nahar, Md. Hossain, Jubayer Mahmud, Md. Hossen, Abdul Masud, Moumita, Masayuki Fujita
      First page: 31
      Abstract: Among the plant nutrients, potassium (K) is one of the vital elements required for plant growth and physiology. Potassium is not only a constituent of the plant structure but it also has a regulatory function in several biochemical processes related to protein synthesis, carbohydrate metabolism, and enzyme activation. Several physiological processes depend on K, such as stomatal regulation and photosynthesis. In recent decades, K was found to provide abiotic stress tolerance. Under salt stress, K helps to maintain ion homeostasis and to regulate the osmotic balance. Under drought stress conditions, K regulates stomatal opening and helps plants adapt to water deficits. Many reports support the notion that K enhances antioxidant defense in plants and therefore protects them from oxidative stress under various environmental adversities. In addition, this element provides some cellular signaling alone or in association with other signaling molecules and phytohormones. Although considerable progress has been made in understanding K-induced abiotic stress tolerance in plants, the exact molecular mechanisms of these protections are still under investigation. In this review, we summarized the recent literature on the biological functions of K, its uptake, its translocation, and its role in plant abiotic stress tolerance.
      Citation: Agronomy
      PubDate: 2018-03-12
      DOI: 10.3390/agronomy8030031
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 32: Agromorphological Traits and Mineral Content
           in Tomato Accessions from El Salvador, Central America

    • Authors: José Chávez-Servia, Araceli Vera-Guzmán, Lesser Linares-Menéndez, José Carrillo-Rodríguez, Elia Aquino-Bolaños
      First page: 32
      Abstract: The agromorphological traits and phenotypic variation of mineral content in the fruit were evaluated in eleven tomato accessions from nine communities in El Salvador. The tomato collection was cultivated in a greenhouse with a randomized complete block design with three replications. Plant phenological and fruit traits, as well as the mineral content, were evaluated using atomic-absorption and ultraviolet-visible spectroscopy. In the analysis of variance, significant differences (p < 0.01) among the accessions were determined for agromorphological traits and all mineral elements except Cu. Plant height at 30, 60 and 90 days after transplant, days to flowering and maturating of the fruits, and the number and weight of fruits per plant were useful variables for describing the phenotypic divergences among the tomato accessions. In terms of mineral content, the differences among the accessions were based on Mg, P, S, Fe, Zn and Mn. The weights of the fruits per cluster and per plant and fruit weight presented negative correlations with Ca, Mg, Fe and P (r = −0.67 to −0.71, p < 0.05) and a positive correlation with Na (0.63).
      Citation: Agronomy
      PubDate: 2018-03-14
      DOI: 10.3390/agronomy8030032
      Issue No: Vol. 8, No. 3 (2018)
  • Agronomy, Vol. 8, Pages 9: Diversity of Maize Kernels from a Breeding
           Program for Protein Quality III: Ionome Profiling

    • Authors: Abdullah Jaradat, Walter Goldstein
      First page: 9
      Abstract: Densities of single and multiple macro- and micronutrients were estimated in the mature kernels of 1348 accessions in 13 maize genotypes. The germplasm belonged to stiff stalk (SS) and non-stiff stalk (NS) heterotic groups (HGs) with one (S1) to four (S4) years of inbreeding (IB), or open pollination (OP), and with opaque or translucent endosperm (OE and TE, respectively). Indices were calculated for macronutrients (M-Index), micronutrients (m-Index) and an index based on Fe and Zn densities (FeZn-Index). The objectives were to (1) build predictive models and quantify multivariate relationships between single and multiple nutrients with physical and biochemical constituents of the maize kernel; (2) quantify the effects of IB stages and endosperm textures, in relation to carbon and nitrogen allocation, on nutrients and their indices; and (3) develop and test the utility of hierarchical multi-way classification of nutrients with kernel color space coordinates. Differences among genotypes and among IB stages accounted for the largest amount of variation in most nutrients and in all indices, while genotypic response to IB within HGs explained 52.4, 55.9, and 76.0% of variation in the M-Index, m-Index, and FeZn-Index, respectively. Differences in C and N allocation among HGs explained more variation in all indices than respective differences in allocation among endosperm (E) textures, while variation decreased with sequential inbreeding compared to OP germplasm. Specific color space coordinates indicated either large macronutrient densities and M-Index, or large micronutrient densities, m-Index, and FeZn-Index. These results demonstrated the importance of genotypes and the C:N ratio in nutrient allocation, as well as bivariate and multiple interrelationships.
      Citation: Agronomy
      PubDate: 2018-01-23
      DOI: 10.3390/agronomy8020009
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 10: On-Farm Demonstrations with a Set of Good
           Agricultural Practices (GAPs) Proved Cost-Effective in Reducing
           Pre-Harvest Aflatoxin Contamination in Groundnut

    • Authors: Vijayaraju Parimi, Vijay Kotamraju, Hari Sudini
      First page: 10
      Abstract: Aflatoxin contamination in groundnut is an important qualitative issue posing a threat to food safety. In our present study, we have demonstrated the efficacy of certain good agricultural practices (GAPs) in groundnut, such as farmyard manure (5 t/ha), gypsum (500 kg/ha), a protective irrigation at 90 days after sowing (DAS), drying of pods on tarpaulins after harvest in farmers’ fields. During 2013–2015, 89 on-farm demonstrations were conducted advocating GAPs, and compared with farmers’ practices (FP) plots. Farmers’ awareness of GAPs, and knowledge on important aspects of groundnut cultivation, were also assessed during our experimentation in the selected villages under study. Pre-harvest kernel infection by Aspergillus flavus, aflatoxin contamination, and pod yields were compared in GAPs plots, vis-à-vis FP plots. The cost of cultivation in both the plots was calculated and compared, based on farmer’s opinion surveys. Results indicate kernel infections and aflatoxins were significantly lower, with 13–58% and 62–94% reduction, respectively, in GAPs plots over FP. Further, a net gain of around $23 per acre was realized through adoption of GAPs by farmers besides quality improvement of groundnuts. Based on our results, it can be concluded that on-farm demonstrations were the best educative tool to convince the farmers about the cost-effectiveness, and adoptability of aflatoxin management technologies.
      Citation: Agronomy
      PubDate: 2018-01-24
      DOI: 10.3390/agronomy8020010
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 11: Utilizing Process-Based Modeling to Assess the
           Impact of Climate Change on Crop Yields and Adaptation Options in the
           Niger River Basin, West Africa

    • Authors: Uvirkaa Akumaga, Aondover Tarhule, Claudio Piani, Bouba Traore, Ado Yusuf
      First page: 11
      Abstract: Climate change is estimated to substantially reduce crop yields in Sub-Saharan West Africa by 2050. Yet, a limited number of studies also suggest that several adaptation measures may mitigate the effects of climate change induced yield loss. In this paper, we used AquaCrop, a process-based model developed by the FAO (The Food and Agriculture Organization, Rome, Italy), to quantify the risk of climate change on several key cereal crops in the Niger Basin. The crops analyzed include maize, millet, and sorghum under rain fed cultivation systems in various agro-ecological zones within the Niger Basin. We also investigated several adaptation strategies, including changes in the sowing dates, soil nutrient status, and cultivar. Future climate change is estimated using nine ensemble bias-corrected climate model projection results under RCP4.5 and RCP8.5 (RCP—Representative Concentration Pathway) emissions scenario at mid future time period, 2021/25–2050. The results show that on average, temperature had a larger effect on crop yields so that the increase in precipitation could still be a net loss of crop yield. Our simulated results showed that climate change effects on maize and sorghum yield would be mostly positive (2% to 6% increase) in the Southern Guinea savanna zone while at the Northern Guinea savanna zone it is mostly negative (2% to 20% decrease). The results show that at the Sahelian zone the projected changes in temperature and precipitation have little to no impact on millet yield for the future time period, 2021/25–2050. In all agro-ecological zones, increasing soil fertility from poor fertility to moderate, near optimal and optimal level significantly reversed the negative yield change respectively by over 20%, 70% and 180% for moderate fertility, near optimal fertility, and optimal fertility. Thus, management or adaptation factors, such as soil fertility, had a much larger effect on crop yield than the climatic change factors. These results provide actionable guidance on effective climate change adaptation strategies for rain fed agriculture in the region.
      Citation: Agronomy
      PubDate: 2018-01-27
      DOI: 10.3390/agronomy8020011
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 12: Grassland Establishment of Dwarf Napiergrass
           (Pennisetum purpureum Schumach) by Planting of Cuttings in the Winter

    • Authors: Satoru Fukagawa, Yasuyuki Ishii
      First page: 12
      Abstract: We investigated a new method for the establishment of dwarf Napiergrass by covering stem cuttings with soil in the winter season analogously to summer establishment in sugarcane. Three experiments were conducted, including measuring the labor involved in plant establishment, and an extension study was applied to livestock producers’ fields in two locations. Using this technique, we obtained an emerged plant density of over two plants/m2. Moreover, this proved a simple and labor-saving method compared with manual or mechanical transplanting. Sowing of Italian ryegrass at the same time as covering cuttings of dwarf Napiergrass with soil could control spring weed growth without disturbing the emergence of dwarf Napiergrass, suggesting the feasibility of a double-cropping forage production system in the region.
      Citation: Agronomy
      PubDate: 2018-01-28
      DOI: 10.3390/agronomy8020012
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 13: Cultivar Variety and Added Potassium Influence
           the Nutraceutical and Antioxidant Content in Hydroponically Grown Basil
           (Ocimum basilicum L.)

    • Authors: Lilia Salas-Pérez, Tiziana Fornari-Reale, Pablo Preciado-Rangel, José García-Hernández, Esteban Sánchez-Chávez, Enrique Troyo-Diéguez
      First page: 13
      Abstract: The potential impact of increased levels of potassium (K+) in hydroponic solution on the production of bioactive compounds, which provide added value to products, is relevant for local economy and human health. This research pursues assessing different levels of K+ on the nutrition of basil, an important aromatic crop in the arid region of La Laguna, northern México, where water scarcity demands the conversion from open-field agriculture to hydroponics. A randomized complete block design with a factorial arrangement (3 × 4) was used to determine the content of nutraceutical components, including polyphenolic compounds, flavonoids, anthocyanins, vitamin C, chlorophylls, and the antioxidant capacity of three varieties of hydroponic basil, with four doses of K+ in the nutrient solution, 7, 9, 11 and 13 mmol L−1. The analysis of variance showed significant differences (p ≤ 0.001) in most of the response variables, caused by the genotype and doses of K+. The antioxidant capacity of assessed cultivars was improved when doses of K+ were increased in the nutrient solution. Furthermore, the antioxidant capacity was positively correlated to the content of flavonoids (r = 0.621), anthocyanins (r = 0.655) and total phenolic compounds (r = 0.549). In conclusion, the nutraceutical content was increased in basil when controlling K+ in the nutrient solution.
      Citation: Agronomy
      PubDate: 2018-01-30
      DOI: 10.3390/agronomy8020013
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 14: Effects of Climate Change on Grassland
           Biodiversity and Productivity: The Need for a Diversity of Models

    • Authors: Marcel van Oijen, Gianni Bellocchi, Mats Höglind
      First page: 14
      Abstract: There is increasing evidence that the impact of climate change on the productivity of grasslands will at least partly depend on their biodiversity. A high level of biodiversity may confer stability to grassland ecosystems against environmental change, but there are also direct effects of biodiversity on the quantity and quality of grassland productivity. To explain the manifold interactions, and to predict future climatic responses, models may be used. However, models designed for studying the interaction between biodiversity and productivity tend to be structurally different from models for studying the effects of climatic impacts. Here we review the literature on the impacts of climate change on biodiversity and productivity of grasslands. We first discuss the availability of data for model development. Then we analyse strengths and weaknesses of three types of model: ecological, process-based and integrated. We discuss the merits of this model diversity and the scope for merging different model types.
      Citation: Agronomy
      PubDate: 2018-02-02
      DOI: 10.3390/agronomy8020014
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 15: Autonomous Mower vs. Rotary Mower: Effects on
           Turf Quality and Weed Control in Tall Fescue Lawn

    • Authors: Michel Pirchio, Marco Fontanelli, Christian Frasconi, Luisa Martelloni, Michele Raffaelli, Andrea Peruzzi, Monica Gaetani, Simone Magni, Lisa Caturegli, Marco Volterrani, Nicola Grossi
      First page: 15
      Abstract: Autonomous mowers are battery-powered machines designed for lawn mowing that require very low human labour. Autonomous mowers can increase turf quality and reduce local noise and pollution compared with gasoline-powered rotary mowers. However, very little is known about the effects of autonomous mowing on encroaching weeds. The aim of this research was to compare the effects of an autonomous mower and an ordinary gasoline-powered mower on weed development in an artificially infested tall fescue (Festuca arundinacea Schreb.) turf with different nitrogen (N) rates. A three-way factor experimental design with three replications was adopted. Factor A consisted of three N rates (0, 75, and 150 kg ha−1), factor B consisted of two mowing systems (autonomous mower vs. walk-behind gasoline rotary mower equipped for mulching), and factor C which consisted of four different transplanted weed species: (a) Bellis perennis L., (b) Trifolium repens L.; (c) Trifolium subterraneum L.; and (d) Lotus corniculatus L. Of these, B. perennis is a rosette-type plant, while the other three species are creeping-type plants. The interaction between mowing system and transplanted weed species showed that the four transplanted weed species were larger when mowed by the autonomous mower than by the rotary mower. The autonomous mower yielded larger weeds probably because the constant mowing height caused the creeping weed species to grow sideways, since the turfgrass offered no competition for light. N fertilization increased turf quality and mowing quality, and also reduced spontaneous weed infestation. Autonomous mowing increased turf quality, mowing quality, but also the percentage of spontaneous weed cover.
      Citation: Agronomy
      PubDate: 2018-02-06
      DOI: 10.3390/agronomy8020015
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 16: Towards Remote Estimation of Radiation Use
           Efficiency in Maize Using UAV-Based Low-Cost Camera Imagery

    • Authors: Andreas Tewes, Jürgen Schellberg
      First page: 16
      Abstract: Radiation Use Efficiency (RUE) defines the productivity with which absorbed photosynthetically active radiation (APAR) is converted to plant biomass. Readily used in crop growth models to predict dry matter accumulation, RUE is commonly determined by elaborate static sensor measurements in the field. Different definitions are used, based on total absorbed PAR (RUEtotal) or PAR absorbed by the photosynthetically active leaf tissue only (RUEgreen). Previous studies have shown that the fraction of PAR absorbed (fAPAR), which supports the assessment of RUE, can be reliably estimated via remote sensing (RS), but unfortunately at spatial resolutions too coarse for experimental agriculture. UAV-based RS offers the possibility to cover plant reflectance at very high spatial and temporal resolution, possibly covering several experimental plots in little time. We investigated if (a) UAV-based low-cost camera imagery allowed estimating RUEs in different experimental plots where maize was cultivated in the growing season of 2016, (b) those values were different from the ones previously reported in literature and (c) there was a difference between RUEtotal and RUEgreen. We determined fractional cover and canopy reflectance based on the RS imagery. Our study found that RUEtotal ranges between 4.05 and 4.59, and RUEgreen between 4.11 and 4.65. These values are higher than those published in other research articles, but not outside the range of plausibility. The difference between RUEtotal and RUEgreen was minimal, possibly due to prolonged canopy greenness induced by the stay-green trait of the cultivar grown. The procedure presented here makes time-consuming APAR measurements for determining RUE especially in large experiments superfluous.
      Citation: Agronomy
      PubDate: 2018-02-06
      DOI: 10.3390/agronomy8020016
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 17: Molecular Markers Improve Breeding Efficiency
           in Apomictic Poa Pratensis L.

    • Authors: B. Bushman, Alpana Joshi, Paul Johnson
      First page: 17
      Abstract: Kentucky bluegrass (Poa pratensis L.) is a highly adapted and important turfgrass species in cool-season climates. It has high and variable polyploidy, small and metacentric chromosomes, and a facultative apomictic breeding system. As a result of the polyploidy and apomixis, identifying hybrids for Mendelian selection, identifying fixed apomictic progeny of desirable hybridizations for cultivar development, or differentiating among cultivars with subtle phenotypic differences is challenging without the assistance of molecular markers. Herein, we show data and review previous research showing the uses and limitations of using molecular markers for hybrid detection, apomixis assessment, and cultivar discrimination. In order to differentiate among different apomictic offtypes, both molecular markers and flow cytometry are necessary. For assessing similarity among progeny of hybridizations, as well as discriminating among cultivars, sets of markers are necessary and cryptic molecular variation must be considered. High throughput genotyping platforms are critical for increased genotyping efficiency.
      Citation: Agronomy
      PubDate: 2018-02-10
      DOI: 10.3390/agronomy8020017
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 18: Quantifying Variability in Maize Yield
           Response to Nutrient Applications in the Northern Nigerian Savanna

    • Authors: Bello Shehu, Roel Merckx, Jibrin Jibrin, Alpha Kamara, Jairos Rurinda
      First page: 18
      Abstract: Diagnostic on-farm nutrient omission trials were conducted over two cropping seasons (2015 and 2016) to assess soil nutrients related constraints to maize yield in the northern Nigerian savanna agro-ecological zone and to quantify their variability. Two sets of trials were conducted side by side, one with an open pollinated maize variety (OPV) and the other one with a hybrid maize variety and each set had six equal treatments laid out in 198 farmers’ fields. The treatments comprised (i) a control, (ii) a PK (‘−N,’ without N), (iii) an NK (‘−P,’ without P), (iv) an NP (‘−K,’ without K), (v) an NPK and (vi) an NPK + S + Ca + Mg + Zn + B (‘+SMM,’ NPK plus secondary macro- and micro-nutrients). Moderate to a large variability in most soil characteristics was observed in the studied fields. Consequently, cluster analysis revealed three distinct yield-nutrient response classes common for the two types of maize varieties. These define classes were fields that have (i) no-response to any nutrient, (ii) a large response to N and P and (iii) a large response to N alone. Although overall yield performance of OPV and hybrid varieties was similar, a distinct fourth class was identified for the hybrid variety, (iv) fields with a large response to N and secondary macro- and micro-nutrients. The results indicate that the large variability in soil nutrients related constraints need to be accounted for to optimize maize yield in the northern Nigerian savanna. The development of field- and area-specific fertilizer recommendations is highly needed, using simple decision support tools that consider variable soil fertility conditions and yield responses as obtained from this study.
      Citation: Agronomy
      PubDate: 2018-02-10
      DOI: 10.3390/agronomy8020018
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 19: Cropping Systems and Climate Change in Humid
           Subtropical Environments

    • Authors: Ixchel Hernandez-Ochoa, Senthold Asseng
      First page: 19
      Abstract: In the future, climate change will challenge food security by threatening crop production. Humid subtropical regions play an important role in global food security, with crop rotations often including wheat (winter crop) and soybean and maize (summer crops). Over the last 30 years, the humid subtropics in the Northern Hemisphere have experienced a stronger warming trend than in the Southern Hemisphere, and the trend is projected to continue throughout the mid- and end of century. Past rainfall trends range, from increases up to 4% per decade in Southeast China to −3% decadal decline in East Australia; a similar trend is projected in the future. Climate change impact studies suggest that by the middle and end of the century, wheat yields may not change, or they will increase up to 17%. Soybean yields will increase between 3% and 41%, while maize yields will increase by 30% or decline by −40%. These wide-ranging climate change impacts are partly due to the region-specific projections, but also due to different global climate models, climate change scenarios, single-model uncertainties, and cropping system assumptions, making it difficult to make conclusions from these impact studies and develop adaptation strategies. Additionally, most of the crop models used in these studies do not include major common stresses in this environment, such as heat, frost, excess water, pests, and diseases. Standard protocols and impact assessments across the humid subtropical regions are needed to understand climate change impacts and prepare for adaptation strategies.
      Citation: Agronomy
      PubDate: 2018-02-14
      DOI: 10.3390/agronomy8020019
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 20: The ALMT Gene Family Performs Multiple
           Functions in Plants

    • Authors: Jie Liu, Meixue Zhou
      First page: 20
      Abstract: The aluminium activated malate transporter (ALMT) gene family is named after the first member of the family identified in wheat (Triticum aestivum L.). The product of this gene controls resistance to aluminium (Al) toxicity. ALMT genes encode transmembrane proteins that function as anion channels and perform multiple functions involving the transport of organic anions (e.g., carboxylates) and inorganic anions in cells. They share a PF11744 domain and are classified in the Fusaric acid resistance protein-like superfamily, CL0307. The proteins typically have five to seven transmembrane regions in the N-terminal half and a long hydrophillic C-terminal tail but predictions of secondary structure vary. Although widely spread in plants, relatively little information is available on the roles performed by other members of this family. In this review, we summarized functions of ALMT gene families, including Al resistance, stomatal function, mineral nutrition, microbe interactions, fruit acidity, light response and seed development.
      Citation: Agronomy
      PubDate: 2018-02-14
      DOI: 10.3390/agronomy8020020
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 21: Dynamic Carbohydrate Supply and Demand Model
           of Vegetative Growth: Response to Temperature, Light, Carbon Dioxide, and
           Day Length

    • Authors: Martin P. N. Gent
      First page: 21
      Abstract: Predicting the growth response of seedlings from the environmental responses of photosynthesis and metabolism may be improved by considering the dynamics of non-structural carbohydrate (NSC) over a diurnal cycle. Attenuation of growth metabolism when NSC content is low could explain why some NSC is conserved through the night. A dynamic model, incorporating diurnal variation in NSC, is developed to simulate growth of seedlings hour-by-hour. I compare predictions of this model to published growth and NSC data for seedlings that varied according to temperature, light, day length, or CO2. Prolonged-darkness experiments show a temperature dependent upper limit on the respiration capacity. Respiration is attenuated as NSC is depleted. Furthermore, when NSC is high at dawn, inhibition of photosynthesis could attenuate the accumulation of NSC under low temperature, high light, or high CO2. These concepts are used to simulate plant metabolism and growth rates and diurnal variation of NSC in tomato seedlings under two light levels and various temperatures. Comparison of other results using the same model parameters show the dynamic model could predict results for starch and starch-less plants, and when growth was affected by CO2 enrichment and day length.
      Citation: Agronomy
      PubDate: 2018-02-16
      DOI: 10.3390/agronomy8020021
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 22: Effect of Digestate and Biochar Amendments on
           Photosynthesis Rate, Growth Parameters, Water Use Efficiency and Yield of
           Chinese Melon (Cucumis melo L.) under Saline Irrigation

    • Authors: Mohammed M. A. Elbashier, Shao Xiaohou, Albashir A. S. Ali, Alnail Mohmmed
      First page: 22
      Abstract: Despite the recent interest in biochar and digestate as soil amendments for improving soil quality and increasing crop production, there is inadequate knowledge of the effect of the combination of biochar and digestate, particularly under saline irrigation conditions. A pot experiment with Chinese melon was conducted in a greenhouse, biochar (5%) and digestate (500 mL/pot) were used with and without the recommended mineral NPK (Nitrogen, Phosphorus and Potassium) fertilizer dose (120-150-150 Kg ha−1). The plants were irrigated with tap water (SL0) and 2 dS/m (SL1) NaCl solution. The growth, photosynthesis rate, water use efficiency (WUE) and yield of Chinese melon were affected positively when biochar was combined with digestate amendment, particularly under saline irrigation water with and without mineral NPK fertilizer. The maximum yield under normal water was obtained by digestate (SL0: 218.87 t ha−1) and biochar amendment combined with digestate (SL1: 118.8 t ha−1) under saline water. The maximum WUE values were noticed with the biochar and digestate combination under all water treatments (SL0: 32.2 t ha−1 mm−1 and SL1: 19.6 t ha−1 mm−1). It was concluded that digestate alone was more effective than the use of biochar, particularly with normal water. The combination of biochar with digestate had a significant effect on the Chinese melon growth, photosynthesis rate, water use efficiency and yield under saline irrigation, and it can be used as an alternative fertilizer for mineral NPK fertilizer.
      Citation: Agronomy
      PubDate: 2018-02-20
      DOI: 10.3390/agronomy8020022
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 23: A Tool for the Evaluation of Irrigation Water
           Quality in the Arid and Semi-Arid Regions

    • Authors: Lucia Bortolini, Carmelo Maucieri, Maurizio Borin
      First page: 23
      Abstract: In the Mediterranean arid and semi-arid regions, large amounts of low quality waters could be used for crop irrigation, but the adoption of articulated classifications with too rigid quality limits can often reduce the recoverable quantities of water and make the monitoring of water quality too much expensive. Therefore, an evaluation of irrigation water quality based on only a few crucial parameters, which consider the crop species to be irrigated and the type of irrigation system and management adopted, can be an easy and flexible method for maximizing the reuse of wastewater and low-quality water for agricultural purposes. In this view, an irrigation water quality tool (IWQT) was developed to support farmers of arid and semi-arid regions on evaluating the use of low quality water for crop irrigation. The most significant and cheapest parameters of irrigation water quality were identified and clustered in three quality classes according to their effects on crop yield and soil fertility (agronomic quality indicators), human health (hygiene and health quality indicators), and irrigation systems (management quality indicators). According to IWQT parameters, a tool reporting a series of recommendations, including water treatment types, was implemented to guide farmers on the use of low quality irrigation water.
      Citation: Agronomy
      PubDate: 2018-02-22
      DOI: 10.3390/agronomy8020023
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 24: Protein, Calcium, Zinc, and Iron Contents of
           Finger Millet Grain Response to Varietal Differences and Phosphorus
           Application in Kenya

    • Authors: Wekha Wafula, Nicholas Korir, Henry Ojulong, Moses Siambi, Joseph Gweyi-Onyango
      First page: 24
      Abstract: This study was carried out to investigate the influence of phosphorus fertilizers on the concentrations of nutrients, particularly calcium, protein, zinc, and iron in finger millet grains grown in different agro-ecologies in Kenya. The on-station experiments were carried out at Kiboko (Eastern Kenya), Kakamega, and Alupe (Western Kenya) in 2015 during the short and long rainy seasons. The trials were laid out in a randomized complete block design (RCBD) in a 4 × 3 factorial arrangement with three replicates. The treatments comprised of four levels of phosphorus (0, 12.5, 25.0 and 37.5 kg ha−1 P2O5) and three finger millet varieties (U-15, P-224 and a local variety). Application of phosphorus significantly (p ≤ 0.05) increased the protein content of finger millet grain in varieties in all the three sites. Variety U-15 had the highest protein content (11.0%) at 25 kg ha−1 P2O5 with the control (zero P) on variety P-224 eliciting the lowest (4.4%) at Kiboko. At Kakamega, the 25 kg ha−1 P2O5 treatment with U-15 variety had the highest protein content (15.3%) while the same variety at 12.5 kg ha−1 P2O5 rate elicited the highest protein content (15.0%) at Alupe. Phosphorus application significantly enhanced the nutritional quality of finger millet grains specifically protein, calcium, iron, and zinc. Variety P-224 had the highest calcium content in all sites and highest iron content at Kakamega while the local varieties had the highest zinc content in all sites. The varieties responded differently to each quality component but generally, based on the protein content, the 25 kg ha−1 P2O5 is recommended.
      Citation: Agronomy
      PubDate: 2018-02-24
      DOI: 10.3390/agronomy8020024
      Issue No: Vol. 8, No. 2 (2018)
  • Agronomy, Vol. 8, Pages 4: Archaeological Starch

    • Authors: Les Copeland, Karen Hardy
      First page: 4
      Abstract: This article reviews evidence of how starch granules associated with archaeological artefacts provide an insight into the use of plants by our ancestors for food, medicines and cultural activities. The properties of starch relevant to archaeological contexts, methods for examining ancient starch and the types of environmental conditions that would promote survival of starch granules over hundreds of thousands of years as part of the archaeological record, are considered. Starch granules identified in dental calculus are clear indicators of the individual having consumed starchy food as part of the diet. However, surviving starch granules may be only a tiny fraction of those consumed over a lifetime and not necessarily representative of foods that were in the diet. A hypothesis, based on a combination of archaeological, physiological and genetic evidence, that plant foods containing high quantities of digestible starch were essential for the evolution of the modern human phenotype, is discussed.
      Citation: Agronomy
      PubDate: 2018-01-04
      DOI: 10.3390/agronomy8010004
      Issue No: Vol. 8, No. 1 (2018)
  • Agronomy, Vol. 8, Pages 5: Functional Analogues of Salicylic Acid and
           Their Use in Crop Protection

    • Authors: Lydia Faize, Mohamed Faize
      First page: 5
      Abstract: Functional analogues of salicylic acid are able to activate plant defense responses and provide attractive alternatives to conventional biocidal agrochemicals. However, there are many problems that growers must consider during their use in crop protection, including incomplete disease reduction and the fitness cost for plants. High-throughput screening methods of chemical libraries allowed the identification of new compounds that do not affect plant growth, and whose mechanisms of action are based on priming of plant defenses, rather than on their direct activation. Some of these new compounds may also contribute to the discovery of unknown components of the plant immune system.
      Citation: Agronomy
      PubDate: 2018-01-09
      DOI: 10.3390/agronomy8010005
      Issue No: Vol. 8, No. 1 (2018)
  • Agronomy, Vol. 8, Pages 6: Acknowledgement to Reviewers of Agronomy in

    • Authors: Agronomy Editorial Office
      First page: 6
      Abstract: Peer review is an essential part in the publication process, ensuring that Agronomy maintains high quality standards for its published papers.[...]
      Citation: Agronomy
      PubDate: 2018-01-22
      DOI: 10.3390/agronomy8010006
      Issue No: Vol. 8, No. 1 (2018)
  • Agronomy, Vol. 8, Pages 7: Climate Change and Pest Management:
           Unanticipated Consequences of Trophic Dislocation

    • Authors: R. Taylor, Daniel Herms, John Cardina, Richard Moore
      First page: 7
      Abstract: The growth of plants and insects occurs only above a minimum temperature threshold. In insects, the growth rate depends on the temperature above the threshold up to a maximum. In plants the growth rate above the threshold generally depends on the availability of sunlight. Thus, the relative growth rates of crops and insect phytophages are expected to differ between temperature regimes. We should therefore expect insect pest pressure at a location to change with climate warming. In this study, we used actual and simulated climate data developed for the IPCC 4th Assessment Report to drive linked plant and insect growth models to examine likely changes in insect-crop interaction. Projections of insect-crop dynamics through the 21st century suggest increases in pest pressure over much of the American Midwest, which could result in substantial increases in pesticide use to maintain productivity. Thus, climate warming could cause an increase in agriculture’s carbon footprint.
      Citation: Agronomy
      PubDate: 2018-01-17
      DOI: 10.3390/agronomy8010007
      Issue No: Vol. 8, No. 1 (2018)
  • Agronomy, Vol. 8, Pages 8: Responses of Different Panicum miliaceum L.
           Genotypes to Saline and Water Stress in a Marginal Mediterranean

    • Authors: Caterina Caruso, Carmelo Maucieri, Andrea Berruti, Maurizio Borin, Antonio Barbera
      First page: 8
      Abstract: The aims of this study were to evaluate: (1) the effect of sodium chloride (NaCl) and mannitol at different osmotic pressures on the germination of three proso millet (Panicum miliaceum L.) genotypes (VIR 9181, Unikum, and Kinelskoje) under controlled laboratory conditions; and (2) the effects of irrigation water salinity, maximum crop evapotranspiration (ETm) restitution regimes, and arbuscular mycorrhizal fungi (AMF) inoculation on forage production in a marginal Mediterranean soil for the genotypes that showed the highest and lowest seed germination. In the laboratory experiment, the Unikum genotype showed the highest seed germination (95.1%), whereas the lowest was found for Kinelskoje (80.4%). Regardless of the osmoticum type, germination was significantly reduced by osmotic pressure increases. Unikum showed a higher fresh biomass yield (FBY) (620.4 ± 126.3 g m−2) than Kinelskoje (340.0 ± 73.5 g m−2). AMF inoculation did not influence FBY under salt conditions, while in the absence of salt conditions it significantly increased the Unikum FBY (+50.7%) as compared to the uninoculated treatment (552.5 ± 269 g m−2). The 25% ETm significantly reduced FBY in both genotypes (−86.2% and −84.1% for Unikum and Kinelskoje, respectively) sd compared to the 100% ETm treatments (1090.3 ± 49.7 g m−2 in Unikum and 587 ± 72.2 g m−2 in Kinelskoje). The obtained results give novel information about proso millet forage production in low-input agriculture in marginal semi-arid Mediterranean land.
      Citation: Agronomy
      PubDate: 2018-01-18
      DOI: 10.3390/agronomy8010008
      Issue No: Vol. 8, No. 1 (2018)
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