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  Subjects -> ENGINEERING (Total: 1957 journals)
    - CHEMICAL ENGINEERING (150 journals)
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    - ENGINEERING (1124 journals)
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ENGINEERING (1124 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Nanoparticle Research     Hybrid Journal   (3 followers)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (11 followers)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (2 followers)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (5 followers)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (3 followers)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (7 followers)
Journal of Networks     Open Access   (3 followers)
Journal of Oceanography and Marine Science     Open Access   (1 follower)
Journal of Operations Management     Hybrid Journal   (12 followers)
Journal of Optics     Hybrid Journal   (2 followers)
Journal of Organizational Behavior     Hybrid Journal   (17 followers)
Journal of Petroleum Science Research     Open Access   (1 follower)
Journal of Phase Equilibria and Diffusion     Hybrid Journal  
Journal of Power Sources     Partially Free   (20 followers)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (8 followers)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (6 followers)
Journal of Quality and Reliability Engineering     Open Access  
Journal of Quality in Maintenance Engineering     Hybrid Journal   (3 followers)
Journal of Radiation Research and Applied Sciences     Open Access   (1 follower)
Journal of Rare Earths     Full-text available via subscription   (1 follower)
Journal of Real-Time Image Processing     Hybrid Journal   (5 followers)
Journal of Regional Science     Hybrid Journal   (6 followers)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (3 followers)
Journal of Research of NIST     Open Access   (1 follower)
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (1 follower)
Journal of Russian Laser Research     Hybrid Journal  
Journal of Safety Engineering     Open Access   (3 followers)
Journal of Safety Research     Hybrid Journal   (4 followers)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (1 follower)
Journal of Science and Technology Policy Management     Hybrid Journal   (2 followers)
Journal of Scientific Computing     Hybrid Journal   (3 followers)
Journal of Scientific Innovations for Development     Open Access   (1 follower)
Journal of Semiconductors     Full-text available via subscription   (2 followers)
Journal of Sensor Technology     Open Access   (2 followers)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (2 followers)
Journal of Solar Energy     Open Access   (1 follower)
Journal of Solar Energy Engineering     Full-text available via subscription   (13 followers)
Journal of Superconductivity and Novel Magnetism     Partially Free   (1 follower)
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques     Hybrid Journal   (1 follower)
Journal of Surveying Engineering     Full-text available via subscription   (6 followers)
Journal of Technology Management & Innovation     Open Access   (1 follower)
Journal of Telecommunications Management     Full-text available via subscription   (2 followers)
Journal of Testing and Evaluation     Full-text available via subscription   (9 followers)
Journal of the Air & Waste Management Association     Hybrid Journal   (2 followers)
Journal of the Chinese Institute of Engineers     Hybrid Journal  
Journal of the Chinese Institute of Industrial Engineers     Hybrid Journal   (1 follower)
Journal of the Franklin Institute     Full-text available via subscription   (2 followers)
Journal of the Institution of Engineers (India ): Series D     Hybrid Journal  
Journal of the Institution of Engineers (India) : Series B     Hybrid Journal   (1 follower)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal  
Journal of the Institution of Engineers (India): Series A     Hybrid Journal  
Journal of the Institution of Engineers (India): Series C     Hybrid Journal   (1 follower)
Journal of the National Science Foundation of Sri Lanka     Open Access   (1 follower)
Journal of the University of Ruhuna     Open Access  
Journal of Thermal Science and Engineering Applications     Full-text available via subscription   (1 follower)
Journal of Thermal Stresses     Hybrid Journal   (2 followers)
Journal of Transplantation     Open Access   (3 followers)
Journal of Transport and Supply Chain Management     Open Access   (4 followers)
Journal of Transportation Engineering     Full-text available via subscription   (13 followers)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (11 followers)
Journal of Tribology     Full-text available via subscription   (8 followers)
Journal of Turbomachinery     Full-text available via subscription   (6 followers)
Journal of Turbulence     Hybrid Journal  
Journal of Unmanned Vehicle Systems     Full-text available via subscription  
Journal of Urban and Environmental Engineering     Open Access  
Journal of Urban Planning and Development     Full-text available via subscription   (27 followers)
Journal of Urban Regeneration and Renewal     Full-text available via subscription   (9 followers)
Journal of Vibration and Acoustics     Full-text available via subscription   (19 followers)
Journal of Visualization     Hybrid Journal  
Journal of Volcanology and Seismology     Hybrid Journal   (1 follower)
Journal of Wuhan University of Technology-Mater. Sci. Ed.     Hybrid Journal  
Journal of X-Ray Science and Technology     Hybrid Journal  
Journal of Zhejiang University SCIENCE A     Hybrid Journal  
Journal on Chain and Network Science     Full-text available via subscription   (2 followers)
Jurnal Teknologi     Open Access   (1 follower)
Karaelmas Science and Engineering Journal     Open Access  
Kleio     Full-text available via subscription   (2 followers)
Landscape and Ecological Engineering     Hybrid Journal   (3 followers)
Langmuir     Full-text available via subscription   (35 followers)
Leadership and Management in Engineering     Full-text available via subscription   (8 followers)
Learning Technologies, IEEE Transactions on     Hybrid Journal   (9 followers)
Lighting Research and Technology     Hybrid Journal  
Logic and Analysis     Hybrid Journal  
Logica Universalis     Hybrid Journal  
Lubrication Science     Hybrid Journal  
Machines     Open Access  
Machining Science and Technology: An International Journal     Hybrid Journal   (3 followers)
Macromolecular Reaction Engineering     Hybrid Journal  
Magazine of Concrete Research     Hybrid Journal   (4 followers)
Magdeburger Journal zur Sicherheitsforschung     Open Access  
Magnetics Letters, IEEE     Hybrid Journal   (1 follower)
Management and Production Engineering Review     Open Access  
Management Science and Engineering     Open Access   (1 follower)
Manufacturing Engineer     Hybrid Journal   (5 followers)
Manufacturing Research and Technology     Full-text available via subscription   (5 followers)

  First | 4 5 6 7 8 9 10 11 | Last

Pest Management Science    [6 followers]  Follow    
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1526-498X - ISSN (Online) 1526-4998
     Published by John Wiley and Sons Homepage  [1594 journals]   [SJR: 0.99]   [H-I: 64]
  • Genetic structure of Bemisia tabaci Med populations from home range
           countries inferred by nuclear and cytoplasmic markers: impact on the
           distribution of the insecticide resistance genes
    • Authors: N. Gauthier; C. Clouet, A. Perrakis, D. Kapantaidaki, M. Peterschmitt, A. Tsagkarakou
      Pages: n/a - n/a
      Abstract: Background Insecticide Resistance Management in Bemisia tabaci is one of the main issues facing agricultural production today. An extensive survey was undertaken in five Mediterranean countries to examine the resistance status of Med B. tabaci species in its range of geographic origin and the relation between population genetic structure and the distribution of resistance genes. The investigation combined molecular diagnostic tests, sequence and microsatellite polymorphism studies and monitoring of endosymbionts. Results High frequencies of pyrethroid (L925I and T929V, VGSC gene) and organophosphate (F331W, ace1 gene) resistance mutations were found in France, Spain and Greece but not in Morocco and Tunisia. Sequence analyses of the COI gene delineated two closely related mitochondrial groups (Q1 and Q2), which were found either sympatrically (Spain) or separately (France). Only Q1 was observed in Greece, Morocco, and Tunisia. Bayesian analyses based on microsatellite loci revealed three geographically delineated genetic groups (France, Spain, Morocco / Greece / Tunisia) and high levels of genetic differentiation even between neighbouring samples. Evidence was also found for hybridization and asymmetrical gene flow between Q1 and Q2. Conclusions Med B. tabaci is more diverse and structured than reported so far. At a large geographic scale, resistance is affected by population genetic structure, whereas at local scale, agricultural practices appear to play a major role.
      PubDate: 2014-01-23T10:45:36.61826-05:0
      DOI: 10.1002/ps.3733
       
  • Aerosol Emitters Disrupt Codling Moth, Cydia pomonella, Competitively
    • Authors: Peter McGhee; Larry Gut
      Pages: n/a - n/a
      Abstract: Background Isomate® CM MIST aerosol emitters (Pacific BioControl Corp, Vancouver, WA) containing 36 grams of codlemone, (E, E)‐8,10‐dodecadien‐1‐ol, were deployed at various densities in a commercial apple orchard to generate dosage‐response profiles in order to elucidate the behavioral mechanism of disruption. Results Moth captures decreased asymptotically as Isomate® CM MIST densities increased. Data fit to Miller‐Gut and Miller‐de Lame plots yielded straight lines, with positive and negative slopes respectively. Catch of male moths decreased from 28 / trap in the control to 0.9 / trap at the highest emitter density. Disruption of > 90% was realized at emitter densities greater than 3 units per ac. Conclusion The resulting set of profiles explicitly matched the predictions for competitive rather than non‐competitive disruption. Thus, these devices likely disrupt by inducing false plume following rather than by camouflaging traps and females. Five MIST units per ha would be necessary to achieve the same level of CM control provided by a standard pheromone treatment with passive reservoir dispensers. The need for only a few aerosol emitters, 2.5 ‐ 5 units per ha, mitigates the cost of labor required to hand apply hundreds of passive reservoir dispensers; however, a potential weakness in using this technology is that the low deployment density may leave areas of little or no pheromone coverage where mate finding may occur. This technology is likely to benefit substantially from treatment of large contiguous blocks of crop.
      PubDate: 2014-01-23T10:42:02.314489-05:
      DOI: 10.1002/ps.3732
       
  • Indigenous American species of the Bemisia tabaci complex are still
           widespread in the Americas
    • Authors: Leonardo F Barbosa; Julio M Marubayashi, Bruno R De Marchi, Valdir A Yuki, Marcelo A Pavan, Enrique Moriones, Jesús Navas‐Castillo, Renate Krause‐Sakate
      Pages: n/a - n/a
      Abstract: Background Bemisia tabaci is a complex of at least 36 putative cryptic species. Since the late 1980s, the Middle East‐Asia Minor 1 species (MEAM1, formerly known as the B biotype), has emerged in many tropical and subtropical regions of the world and in some areas has displaced the indigenous populations of B. tabaci. Based on analysis of the mtCOI gene, two indigenous species native to America have been reported: New World (NW, formerly the A biotype) and New World 2 (NW2). Results Here, we highlight that NW is present at least in Argentina, Brazil, Martinique, Mexico, Texas and Venezuela, and NW2 in Argentina, Bolivia and Brazil. Wild plants (Euphorbia sp. and Ipomoea sp.) as well as important crops such as tomato, bean and cotton are still hosts for native B. tabaci populations in the Americas. Conclusion MEAM1 has not completely displaced the native B. tabaci from the Americas.
      PubDate: 2014-01-23T10:33:45.610571-05:
      DOI: 10.1002/ps.3731
       
  • Modelling the potential distribution of Bemisia tabaci in Europe
           considering climate change scenario
    • Authors: Gianni Gilioli; Sara Pasquali, Simone Parisi, Stephan Winter
      Pages: n/a - n/a
      Abstract: Background Bemisia tabaci is a serious pest of agricultural and horticultural crops in green house and in the field around the world. This paper deals with the distribution of the pest under field condition. In Europe, the insect currently is found in coastal regions of Mediterranean countries where it is subject to quarantine regulations. To assess the risk presented by B. tabaci for Europe, the area of potential establishment of this insect considering climate change scenario was assessed by a temperature‐dependent physiologically‐based demographic model (PBDM). Results The simulated potential distribution under current climate conditions has been successfully validated with the available field records of B. tabaci in Europe. Considering climate change scenarios of +1 and + 2°C, range expansion by B. tabaci is predicted particularly in Spain, France, Italy, Greece and along the Adriatic coast of the Balkans. Notwithstanding, even under the scenario of +2 °C, northern European countries are not likely at risk of B. tabaci establishment because of climatic limitations. Conclusion Model validation with field observations and evaluation of uncertainties associated to model parameters variability support the reliability of model results. The PBDM developed here can be applied to other organisms and offers significant advantages for assessing the potential distribution of invasive species.
      PubDate: 2014-01-23T10:31:46.751925-05:
      DOI: 10.1002/ps.3734
       
  • Nematicidal activity of fluensulfone against some migratory nematodes
           under laboratory conditions
    • Authors: Yuji Oka
      Pages: n/a - n/a
      Abstract: Background The fluoroalkenyl fluensulfone, known to have strong nematicidal activity against Meloidogyne spp. (root‐knot nematodes), was evaluated in vitro and in soil against the migratory nematodes Bursaphelenchus xylophilus, Aphelenchoides besseyi, Aphelenchoides fragariae, Ditylenchus dipsaci, Pratylenchus penetrans, Pratylenchus thornei and Xiphinema index. Results B. xylophilus and D. dipsaci were not immobilized by 48‐h in‐vitro exposure to up to 16 mg L‐1 fluensulfone. A. besseyi and A. fragariae were affected by 8 mg L‐1, the highest concentration used to these nematodes. More than 60% of P. penetrans and P. thornei were immobilized by 4 mg L‐1 fluensulfone; however, exposure of P. penetrans to the compound prior to inoculation did not affect their root‐penetration ability. Immobilization rate of X. index was increased by 48‐h exposure to even 1.0 mg L‐1 fluensulfone. Incorporation of over 2 mg L ‐1 fluensulfone into the soil reduced populations of P. penetrans and P. thornei before and after planting lettuce and chickpea, respectively. The efficacy of fluensulfone against the tested nematodes was the same or higher than that of fenamiphos in most cases. Conclusion A. besseyi, A. fragariae, B. xylophilus and D. dipsaci were tolerant to fluensulfone and fenamiphos. P. penetrans, P. thornei and X. index were affected by fluensulfone, but nematicidal activity was much lower than that reported for root‐knot nematodes.
      PubDate: 2014-01-22T10:46:45.76817-05:0
      DOI: 10.1002/ps.3730
       
  • Mechanisms of resistance to paraquat in plants
    • Authors: Timothy R Hawkes
      Pages: n/a - n/a
      Abstract: The aim of this brief review is to draw information from studies of the mechanism of evolved resistance in weeds, together with information from laboratory studies of paraquat tolerance in model plants. Plants having mutations that limit paraquat uptake into cytoplasm, that confer various stress tolerances or that have transgenes that co‐express two or more of the chloroplast Halliwell–Asada cycle enzymes can all exhibit enhanced tolerance to paraquat. However, none of these mechanisms correspond to the high‐level resistances that have evolved naturally in weeds. Most, but not all, of the evidence from studies of paraquat‐resistant biotypes of weeds can reasonably be reconciled with the proposal of a single major gene mechanism that sequesters paraquat away from chloroplasts and into the vacuole. However, the molecular details of this putative mechanism remain ill‐defined. © 2013 Society of Chemical Industry
      PubDate: 2014-01-21T10:55:53.131738-05:
      DOI: 10.1002/ps.3699
       
  • Market‐level assessment of the economic benefits of atrazine in the
           United States
    • Authors: Paul D Mitchell
      Pages: n/a - n/a
      Abstract: BACKGROUND Atrazine and other triazine herbicides are widely used in US maize and sorghum production, yet the most recent market‐level assessment of the economic benefits of atrazine is for market conditions prevalent in the early 1990s, before commercialization of transgenic crops. Grain markets have changed substantially since that time; for example, the size of the US maize market increased by 170% from 1990–1992 to 2007–2009. This paper reports a current assessment of the economic benefits of atrazine. RESULTS Yield increases and cost changes implied by triazine herbicides are projected to reduce maize prices by 7–8% and sorghum prices by 19–20%. Projected consumer benefits from lower prices range from $US 3.6 to 4.4 × 109 annually, with the net projected economic benefit for triazine herbicides to the US economy ranging from $US 2.9 to 3.4 × 109 annually because lower prices imply reduced producer income. Productivity gains from triazine herbicides maintain an estimated 270 000–390 000 ha of land in non‐crop uses that generate environmental benefits not accounted for in this analysis. CONCLUSION Even in the current era, with transgenic varieties dominating crop production, atrazine and the other triazine herbicides continue to be a key part of maize and sorghum production and generate substantial economic benefits. © 2013 The
      Authors . PestManagement Science published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2014-01-21T10:54:36.129575-05:
      DOI: 10.1002/ps.3703
       
  • Herbicides and plant hormesis
    • Authors: Regina G. Belz; Stephen O. Duke
      Pages: n/a - n/a
      Abstract: Herbicide hormesis is commonly observed at sub‐toxic doses of herbicides and other phytotoxins. The occurrence and magnitude of this phenomenon is influenced by plant growth stage and physiological status, environmental factors, the endpoint measured, and the timing between treatment and endpoint measurement. The mechanism in some cases of herbicide hormesis appears to be related to the target site of the herbicide, whereas, in other examples hormesis may be by overcompensation to moderate stress induced by the herbicides or a response to disturbed homeostasis. Theoretically, herbicide hormesis could be used in crop production, but this has been practical only in the case of the use of herbicides as sugarcane “ripeners” to enhance sucrose accumulation. The many factors that can influence the occurrence, the magnitude, and the dose range of hormetic increases in yield for most crops make it too unpredictable and risky as a production practice with the currently available knowledge. Herbicide hormesis can cause undesired effects in situations in which weeds are unintentionally exposed to hormetic doses (e.g., in adjacent fields, when shielded by crop vegetation). Some weeds that evolved herbicide resistance may have hormetic responses to recommended herbicide application rates. Little is known about such effects under field conditions. A more complete understanding of herbicide hormesis is needed to exploit its potential benefits and to minimize its potential harmful effects in crop production.
      PubDate: 2014-01-20T10:39:15.401715-05:
      DOI: 10.1002/ps.3726
       
  • Costs and effectiveness of on‐farm measures to reduce aquatic risks
           from pesticides in the Netherlands
    • Authors: M.M. Eerdt; J. Spruijt, A.J. Wal, H. Zeijts, A. Tiktak
      Pages: n/a - n/a
      Abstract: Background The European Union requires growers to implement the principles of Integrated Pest Management (IPM) by 2014. In this paper, we provide a quantitative overview of the costs and effectiveness of voluntary IPM measures in 15 crops in the Netherlands. We will focus on aquatic risks and define effectiveness as the potential to reduce the risks posed to aquatic organisms. We further identify which of these measures have actually been adopted by growers and why certain measures have not been adopted. Results Of the 105 measures evaluated, the most effective measures with respect to risk reduction were emission reduction and substitution of high‐risk pesticides (each up to 80% reduction). IPM measures directed towards lowering pesticide use generally showed a smaller risk reducing potential. However, 40% of these measures reduced the overall cost of pest management. About 60% of all 105 measures were voluntarily implemented by growers. The most commonly adopted measures were pest prevention, low‐dose spraying and spray drift reduction. Cost appeared to be an important incentive for adoption; however, other factors such as risk perception, education and practicability were equally important. Conclusions Voluntary IPM measures have significantly contributed to reducing aquatic risks (15‐50% risk reduction depending on crop type). Further risk reduction could be achieved when more growers adopt the most effective measures like spray drift reduction and substitution of high‐risk pesticides. However, IPM hardly reduced the number of pesticide applications and therefore the dependence on chemical crop protection continued to be high.
      PubDate: 2014-01-20T10:38:31.594384-05:
      DOI: 10.1002/ps.3729
       
  • Current State of Herbicides in Herbicide‐Resistant Crops
    • Authors: Jerry M. Green
      Pages: n/a - n/a
      Abstract: Current herbicide and herbicide trait practices are changing in response to the rapid spread of glyphosate‐resistant weeds. Growers urgently needed glyphosate when glyphosate‐resistant crops became available because weeds were becoming widely resistant to most commonly used selective herbicides, making weed management too complex and time consuming for large farm operations. Glyphosate made weed management easy and efficient by controlling all emerged weeds at a wide range of application timings. However, the intensive use of glyphosate over wide areas and concomitant decline in the use of other herbicides and eventually to the widespread evolution of weeds resistant to glyphosate. Today, weeds that are resistant to glyphosate and other herbicide types are threatening current crop production practices. Unfortunately, all commercial herbicide modes of action are over 20 years old and have resistant weed problems. The severity of the problem is renewing efforts to discover new weed management technologies. One technology will be a new generation of crops with resistance to glyphosate, glufosinate, and other existing herbicide modes of action. Other technologies will include new chemical, biological, cultural, and mechanical methods for weed management. From the onset of commercialization, growers must preserve the utility of new technologies by integrating their use with other weed management technologies in diverse and sustainable systems.
      PubDate: 2014-01-20T10:36:19.038882-05:
      DOI: 10.1002/ps.3727
       
  • Evolution of Resistance to Phytoene Desaturase and Protoporphyrinogen
           Oxidase Inhibitors – State of Knowledge
    • Authors: Franck E. Dayan; Daniel K. Owens, Patrick J. Tranel, Christopher Preston, Stephen O. Duke
      Pages: n/a - n/a
      Abstract: Two major classes of herbicides include inhibitors of protoporphyrinogen oxidase (PPO) and phytoene desaturase (PDS). Plants can evolve resistance to PPO and PDS inhibitors via several mechanisms that include physical changes resulting in reduced uptake, physiological changes resulting in compartmentalization or altered translocation, biochemical changes that result in enhanced metabolic degradation or alterations of protein structures resulting in loss of sensitivity to the herbicides. This review discusses the involvement of some of these mechanisms in the various cases of resistance to PDS and PPO inhibiting herbicides, and highlights unique aspects of target‐site resistance to these herbicides.
      PubDate: 2014-01-20T10:36:14.677495-05:
      DOI: 10.1002/ps.3728
       
  • Management of herbicide resistance in wheat cropping systems: learning
           from the Australian experience
    • Authors: Michael J Walsh; Stephen B Powles
      Pages: n/a - n/a
      Abstract: Herbicide resistance continues to escalate in weed populations infesting global wheat (Triticum aestivum L.) crops, threatening grain production and thereby food supply. Conservation wheat production systems are reliant on the use of efficient herbicides providing low‐cost, selective weed control in intensive cropping systems. The resistance‐driven loss of herbicide resources combined with limited potential for new herbicide molecules means greater emphasis must be placed on preserving existing herbicides. For more than two decades, since the initial recognition of the dramatic consequences of herbicide resistance, the challenge of introducing additional weed control strategies into herbicide‐based weed management programmes has been formidable. Throughout this period, herbicide resistance has expanded unabated across the world's wheat production regions. However, in Australia, where herbicide resources have become desperately depleted, the adoption of harvest weed seed control is evidence, at last, of a successful approach to sustainable weed management in wheat production systems. Growers routinely including strategies to target weed seeds during crop harvest, as part of herbicide‐based weed management programmes, are now realising significant weed control and crop production benefits. When combined with an attitude of zero weed tolerance, there is evidence of a sustainable weed control future for wheat production systems. The hard‐learned lessons of Australian growers can now be viewed by global wheat producers as an example of how to stop the continual loss of herbicide resources in productive cropping systems. © 2013 Society of Chemical Industry
      PubDate: 2014-01-20T04:10:20.194833-05:
      DOI: 10.1002/ps.3704
       
  • Biodegradable herbicide delivery systems with slow diffusion in soil and
           UV protection properties
    • Authors: Anne Chevillard; Hélène Angellier‐Coussy, Valérie Guillard, Cédric Bertrand, Nathalie Gontard, Emmanuelle Gastaldi
      Pages: n/a - n/a
      Abstract: BACKGROUND New herbicidal formulations were designed by combining wheat gluten (WG), two montmorillonites (MMTs) (unmodified and organically modified) and a model pesticide (ethofumesate), and their performances were assessed through an integrative study conducted in soil using an experimental methodology with data modelling. RESULTS All the WG formulations tested were effective in decreasing the apparent diffusivity of ethofumesate in soil in comparison with the non‐formulated active substance. The slow‐release effect was significantly more pronounced in the presence of the organically modified MMT, confirming the importance of sorption mechanisms to reduce ethofumesate diffusion. The bioassays undertaken on watercress to evaluate herbicidal antigerminating performances showed that all the WG formulations (with or without MMT) were more effective than both the commercial formulation and the non‐formulated ethofumesate, whatever the concentration tested. To explain such results, it was proposed that WG formulations would enable ethofumesate to be more available and thus more effective in inhibiting seed germination, as they would be less prone to be leached by water transport due to watering and also less subject to photodegradation. CONCLUSION The use of pesticide formulations based on wheat gluten and nanoclays appeared to be a promising strategy both to reduce the mobility of pesticides in soil and to protect UV‐photosensitive pesticides from photodegradation. © 2013 Society of Chemical Industry
      PubDate: 2014-01-20T04:10:13.558667-05:
      DOI: 10.1002/ps.3705
       
  • Biology, ecology and management of the invasive Parthenium weed
           (Parthenium hysterophorus L.)
    • Authors: Steve W. Adkins; Asad Shabbir
      Pages: n/a - n/a
      Abstract: Parthenium weed (Parthenium hysterophorus L.) is one of the most aggressive invasive weeds, threatening the natural and agro‐ecosystems in over 30 countries worldwide. Parthenium weed inflicts losses to crops and pastures, degrading the biodiversity of natural plant communities, causing human and animal health hazards and seriously inflicting economic losses to people and their interests in many countries around the globe. Several of its biological and ecological attributes contribute towards its invasiveness. Various management approaches (viz. cultural, mechanical, chemical and biological control) have been used to minimize losses caused by this weed but most of these approaches are ineffective, uneconomical and/or have limitations. Although, chemical control using herbicides and biological control utilizing exotic insects and pathogens has been found to contribute to the management of the weed, nevertheless the weed remains a significant problem. An integrated management approach has been proposed here for the effective management of parthenium weed on a sustainable basis.
      PubDate: 2014-01-15T10:35:05.048499-05:
      DOI: 10.1002/ps.3708
       
  • Delousing efficiency of farmed ballan wrasse (Labrus bergylta) against
           Lepeophtheirus salmonis infecting Atlantic salmon (Salmo salar)
           post‐smolts
    • Authors: Eric Leclercq; Andrew Davie, Hervé Migaud
      Pages: n/a - n/a
      Abstract: BACKGROUND Cleaner‐fish (wrasse, Labridae) are increasingly deployed within the Atlantic salmon (Salmo salar L.) industry as a biological control against sea‐lice (Lepeophtheirus salmonis Krøyer). Two tank‐based trials were performed to test the effect of farmed ballan wrasse (Labrus bergylta Ascanius) body mass and supplementary feeding on the delousing of Atlantic salmon post‐smolts with an initial infection level of ∼12 lice salmon−1 and a ∼5% wrasse:salmon ratio. RESULTS Sea‐louse levels below 0.5 lice salmon−1 were obtained within 84 h, and preferential preying upon larger motile stages was found. The wrasse body mass and the availability of fresh, opened blue mussels (Mytilus edulis L.) did not significantly affect delousing efficiency. The functional predator response was linear, showing no minimum prey density threshold for sea‐louse foraging and no satiation plateau, in spite of the high consumption rates measured. Sea‐louse infection levels declined following a one‐phase exponential decay model, with a standardised decline time constant of 0.8–1.3% h−1 for each wrasse stocked per 100 salmon. CONCLUSIONS Farmed ballan wrasse are confirmed as highly effective therapeutic and preventive biological controls against sea‐lice. The study supports the current minimum hatchery size target (10 mm total length) and the use of supplementary feeding to sustain the wrasse stocks in operation. The functional predator response and the standardised decline time constant of sea‐louse abundance are proposed as useful indicators of delousing efficiency. © 2013 Society of Chemical Industry
      PubDate: 2014-01-15T08:39:52.197715-05:
      DOI: 10.1002/ps.3692
       
  • Common vole (Microtus arvalis) ecology and management: implications for
           risk assessment of plant protection products
    • Authors: Jens Jacob; Phil Manson, Ralf Barfknecht, Timothy Fredricks
      Pages: n/a - n/a
      Abstract: Common voles (Microtus arvalis) are common small mammals in some European landscapes. They can be a major rodent pest in European agriculture and they are also a representative generic focal small herbivorous mammal species used in risk assessment for plant protection products. In this paper, common vole population dynamics, habitat and food preferences, pest potential and use of the common vole as a model small wild mammal species in the risk assessment process are reviewed. Common voles are a component of agroecosystems in many parts of Europe, inhabiting agricultural areas (secondary habitats) when the carrying capacity of primary grassland habitats is exceeded. Colonisation of secondary habitats occurs during multiannual outbreaks, when population sizes can exceed 1000 individuals ha−1. In such cases, in‐crop common vole population control management has been practised to avoid significant crop damage. The species' status as a crop pest, high fecundity, resilience to disturbance and intermittent colonisation of crop habitats are important characteristics that should be reflected in risk assessment. Based on the information provided in the scientific literature, it seems justified to modify elements of the current risk assessment scheme for plant protection products, including the use of realistic food intake rates, reduced assessment factors or the use of alternativee focal rodent species in particular European regions. Some of these adjustments are already being applied in some EU member states. Therefore, it seems reasonable consistently to apply such pragmatic and realistic approaches in risk assessments for plant protection products across the EU. © 2013 Society of Chemical Industry
      PubDate: 2014-01-15T08:39:10.136318-05:
      DOI: 10.1002/ps.3695
       
  • Global perspective of herbicide‐resistant weeds
    • Authors: Ian Heap
      Pages: n/a - n/a
      Abstract: Two hundred and twenty weed species have evolved resistance to one or more herbicides, and there are now 404 unique cases (species × site of action) of herbicide‐resistant weeds globally. ALS inhibitor‐resistant weeds account for about a third of all cases (133/404) and are particularly troublesome in rice and cereals. Although 71 weed species have been identified with triazine resistance, their importance has dwindled with the shift towards Roundup Ready® crops in the USA and the reduction of triazine usage in Europe. Forty‐three grasses have evolved resistance to ACCase inhibitors, with the most serious cases being Avena spp., Lolium spp., Phalaris spp., Setaria spp. and Alopecurus myosuroides, infesting more than 25 million hectares of cereal production globally. Of the 24 weed species with glyphosate resistance, 16 have been found in Roundup Ready® cropping systems. Although Conyza canadensis is the most widespread glyphosate‐resistant weed, Amaranthus palmeri and Amaranthus tuberculartus are the two most economically important glyphosate‐resistant weeds because of the area they infest and the fact that these species have evolved resistance to numerous other herbicide sites of action, leaving growers with few herbicidal options for their control. The agricultural chemical industry has not brought any new herbicides with novel sites of action to market in over 30 years, making growers reliant on using existing herbicides in new ways. In addition, tougher registration and environmental regulations on herbicides have resulted in a loss of some herbicides, particularly in Europe. The lack of novel herbicide chemistries being brought to market combined with the rapid increase in multiple resistance in weeds threatens crop production worldwide. © 2013 Society of Chemical Industry
      PubDate: 2014-01-15T08:38:00.675104-05:
      DOI: 10.1002/ps.3696
       
  • Molecular and Phenotypic Characterization of Als1 and Als2 Mutations
           Conferring Tolerance to ALS Herbicides in Soybean
    • Authors: Kay L. Walter; Stephen D. Strachan, Nancy M. Ferry, Henrik H. Albert, Linda A. Castle, Scott A. Sebastian
      Pages: n/a - n/a
      Abstract: Background Sulfonylurea (SU) herbicides are effective because they inhibit acetolactate synthase (ALS), a key enzyme in branch chain amino acid synthesis required for plant growth. A soybean line known as W4‐4 was developed through rounds of seed mutagenesis and was demonstrated to have a high degree of ALS‐based resistance to both post‐emergence and pre‐emergence applications of a variety of SU herbicides. This report describes the molecular and phenotypic characterization of the Als1 and Als2 mutations that confer herbicide resistance to SUs and other ALS inhibitors. Results The mutations are shown to occur in two different ALS genes that reside on different chromosomes: P178S on Als1 and W560L on Als2 (P197S and W574L in Arabidopsis thaliana). Conclusion Although the Als1 and Als2 genes are unlinked, the combination of these two mutations is synergistic for improved tolerance of soybeans to ALS‐inhibiting herbicides.
      PubDate: 2014-01-15T07:18:11.913655-05:
      DOI: 10.1002/ps.3725
       
  • Plant resistance to aphid feeding: behavioral, physiological, genetic and
           molecular cues regulate aphid host selection and feeding
    • Authors: C Michael Smith; Wen‐Po Chuang
      Pages: n/a - n/a
      Abstract: Aphids damage major world food and fiber crops through direct feeding and transmission of plant viruses. Fortunately, the development of many aphid‐resistant crop plants has provided both ecological and economic benefits to food production. Plant characters governing aphid host selection often dictate eventual plant resistance or susceptibility to aphid herbivory, and these phenotypic characters have been successfully used to map aphid resistance genes. Aphid resistance is often inherited as a dominant trait, but is also polygenic and inherited as recessive or incompletely dominant traits. Most aphid‐resistant cultivars exhibit constitutively expressed defenses, but some cultivars exhibit dramatic aphid‐induced responses, resulting in the overexpression of large ensembles of putative aphid resistance genes. Two aphid resistance genes have been cloned. Mi‐1.2, an NBS‐LRR gene from wild tomato, confers resistance to potato aphid and three Meloidogyne root‐knot nematode species, and Vat, an NBS‐LRR gene from melon, controls resistance to the cotton/melon aphid and to some viruses. Virulence to aphid resistance genes of plants occurs in 17 aphid species – more than half of all arthropod biotypes demonstrating virulence. The continual appearance of aphid virulence underscores the need to identify new sources of resistance of diverse sequence and function in order to delay or prevent biotype development. © 2013 Society of Chemical Industry
      PubDate: 2014-01-15T04:35:44.48692-05:0
      DOI: 10.1002/ps.3689
       
  • Degradation of three benzonitrile herbicides by Aminobacter MSH1 versus
           soil microbial communities: pathways and kinetics
    • Authors: Zuzana Frková; Nora Badawi, Anders Johansen, Nadja Schultz‐Jensen, Kai Bester, Sebastian Reinhold Sørensen, Ulrich Gosewinkel Karlson
      Pages: n/a - n/a
      Abstract: BACKGROUND The herbicide dichlobenil was banned in the European Union after its metabolite 2,6‐dichlorobenzamide (BAM) was encountered in groundwater. Owing to structural similarities, bromoxynil and ioxynil might be converted to persistent metabolites in a similar manner. To examine this, we used an indigenous soil bacterium Aminobacter sp. MSH1 which is capable of mineralizing dichlobenil via BAM and 2,6‐dichlorobenzoic acid (2,6‐DCBA). RESULTS Strain MSH1 converted bromoxynil and ioxynil to the corresponding aromatic metabolites, 3,5‐dibromo‐4‐hydroxybenzoic acid (BrAC) and 3,5‐diiodo‐4‐hydroxybenzoic acid (IAC) following Michaelis–Menten kinetics (adjusted R2 between 0.907 and 0.999). However, in contrast to 2,6‐DCBA, degradation of these metabolites was not detected in the pure‐culture studies, suggesting that they might pose an environmental risk if similar partial degradation occurred in soil. By contrast, experiments with natural soils indicated 20–30% mineralization of ioxynil and bromoxynil within the first week. CONCLUSION The degradation pathway of the three benzonitriles is initially driven by similar enzymes, after which more specific enzymes are responsible for further degradation. Ioxynil and bromoxynil mineralization in soil is not dependent on previous benzonitrile exposure. The accumulation of dead‐end metabolites, as seen for dichlobenil, is not a major problem. © 2013 Society of Chemical Industry
      PubDate: 2014-01-13T07:54:54.541716-05:
      DOI: 10.1002/ps.3697
       
  • Contribution of household herbicide usage to glyphosate & its
           degradate, AMPA, in surface water drains
    • Authors: Carmel T Ramwell; Melanie Kah, Paul D Johnson
      Pages: n/a - n/a
      Abstract: Background It is necessary to understand the extent to which different sources of pesticides contribute to surface water contamination in order to focus preventative measures appropriately. The extent to which glyphosate use in the home and garden sector may contribute to surface water contamination has not previously been quantified. The aim of this study was to quantify the widely‐used herbicide, glyphosate, and its degradation product, aminomethylphosphonic acid (AMPA) in surface water drains (storm drains) that could be attributed to amateur, non‐professional usage alone. Results Maximum glyphosate and AMPA concentrations in surface water drains were 8.99 and 1.15 µg/L respectively after the first rain event following the main application period, but concentrations rapidly declined to
      PubDate: 2014-01-11T13:35:32.491202-05:
      DOI: 10.1002/ps.3724
       
  • Activity of flonicamid on the sweet potato whitefly Bemisia tabaci
           (Homoptera: Aleyrodidae) and its natural enemies
    • Authors: Emmanouil Roditakis; Natasa Fytrou, Marianna Staurakaki, John Vontas, Anastasia Tsagkarakou
      Pages: n/a - n/a
      Abstract: Background Flonicamid is a novel systemic insecticide that acts as a feeding blocker with potential use against whiteflies within IPM control tactics. Flonicamid efficacy against Bemisia tabaci Mediterranean populations from Crete was examined, as well as side effects on selected beneficials used extensively in current IPΜ schemes. Results Low variability in adulticide activity was detected (< 10‐ fold), while there was no resistance compared to a reference susceptible population. Flonicamid exhibited low to no insecticidal activity on eggs, emerging crawlers and second instars nymphs at maximum Registered Label Rate (RLRmax). In long term cage experiments, flonicamid at maximum recommended label rate (RLRmax, 125 mg L‐1) caused 95% mortality to whiteflies 10 days after treatment, and delayed population growth by one generation (32 days). Flonicamid significantly delayed nymphal development by increasing development time (DT50) of treated insects by 7.2 days. Flonicamid did not affect the survival of Eretmocerus eremicus adults, while lethal effects of intermediate level were observed to Nesidiocoris tenuis adults and nymphs, Amblyseius swirskii adults and pre‐imaginal stages of E. eremicus. Flonicamid reduced the feeding activity (consumption of B. tabaci eggs) of Ν. tenuis and Α. swirskii by 28 and 37%, respectively. Moreover, the fecundity of A. swirskii was reduced by 36% after exposure to flonicamid. Conclusions Flonicamid is an effective tool for the management of B. tabaci populations from Crete and initial studies indicate that it could be combined with B. tabaci natural enemies.
      PubDate: 2014-01-09T11:16:44.441276-05:
      DOI: 10.1002/ps.3723
       
  • Anadenanthera colubrina (Vell.) Brenan produces steroidal substances that
           are active against Alternaria alternata (Fr.) Keissler and that may bind
           to oxysterol‐binding proteins
    • Authors: Viviane AC Campos; Fabiano J Perina, Eduardo Alves, Jaqueline Sartorelli, Amanda M Moura, Denilson F Oliveira
      Pages: n/a - n/a
      Abstract: Background In previous studies, the extract from Anadenanthera colubrina was active against Alternaria alternata in vitro and reduced the disease caused by this fungus on Murcott tangor fruits to levels that have been obtained using commercial fungicides. Therefore, the goal of the present work was to isolate and identify the active substances in this extract and identify in silico their protein target in the fungus. Results The bioguided fractionation of the methanol extract from the fruits of A. colubrina resulted in the isolation of β‐sitosterol and β‐sitosteryl linoleate, which had minimal inhibitory concentrations (MICs) of 250 and 500 μg mL‐1, respectively, against A. alternata. Under the same conditions, the MICs for two commercial fungicides were 1250 and 19μg mL‐1. In silico studies showed that these steroidal substances bind well to oxysterol‐binding proteins from Saccharomyces cerevisiae. Conclusion β‐sitosterol and β‐sitosteryl linoleate, produced by A. colubrina, are active against A. alternata. In silico studies suggest that these substances may act by binding to oxysterol‐binding proteins. Therefore, both substances and these proteins have potential use in the development of new steroidal structures and analogues to control the disease caused by A. alternata.
      PubDate: 2014-01-09T10:51:44.273332-05:
      DOI: 10.1002/ps.3722
       
  • Fluridone: a combination germination stimulant and herbicide for problem
           fields?
    • Authors: Danica E Goggin; Stephen B Powles
      Pages: n/a - n/a
      Abstract: Background Problem weeds in agriculture, such as Lolium rigidum Gaud., owe some of their success to their large and dormant seed banks, which permit germination throughout a crop‐growing season. Dormant weed seed banks could be greatly depleted by application of a chemical that stimulates early‐season germination and then kills the young seedlings. Fluridone, a phytoene desaturase‐inhibiting herbicide that can also break seed dormancy, was assessed for its efficacy in this regard. Results The germination of fluridone‐treated Lolium rigidum seeds was stimulated on soils with low organic matter and almost 100% seedling mortality was observed, whilst the treatment was only moderately effective on high organic matter potting mix. Seedlings from wheat, canola, common bean and chickpea seeds sown on fluridone‐treated sandy loam were bleached and did not survive, but lupins and field peas grew normally. Conclusion This proof‐of‐concept study with fluridone suggests that it may be possible to design safe and effective molecules that act as germination stimulants plus herbicides in a range of crop and soil types: a potentially novel way of utilising herbicides to stimulate seed bank germination and a valuable addition to an integrated weed management system.
      PubDate: 2014-01-09T10:38:19.860778-05:
      DOI: 10.1002/ps.3721
       
  • Dissipation rate of thiacloprid and its control effect against Bemisia
           tabaci in greenhouse tomato after soil application
    • Authors: Sa Dong; Kang Qiao, Hongyan Wang, Yukun Zhu, Xiaoming Xia, Kaiyun Wang
      Pages: n/a - n/a
      Abstract: BACKGROUND Thiacloprid is a chloronicotinyl insecticide that is quite effective against sucking insects. In this study, when thiacloprid was applied at two different rates (normal rate 15 kg ha−1, double rate 30 kg ha−1), the systemic distribution and residue of thiacloprid as well as its control effect against whitefly (Bemisia tabaci) were investigated in greenhouse tomato after soil application. RESULTS The results showed that thiacloprid was present in the tomato leaves until day 25, and then its amount was less than 0.005 mg kg−1 and could not be detected. Thiacloprid residue in the tomato stems basically remained at a stable low level throughout the experimental period. Thiacloprid in soil had half‐lives of 11.8 and 12.5 days for the normal treatment and the double treatment respectively. The control efficiency of whiteflies was about 90% from day 1 to day 10. This was followed by a slow decline, but efficiency was still higher than 50% until day 21. In addition, no significant differences were noted in the control effect of thiacloprid on whiteflies between the two different rates. CONCLUSION Soil application of thiacloprid at the normal rate can effectively control whiteflies, with high efficiency and long persistence. © 2013 Society of Chemical Industry
      PubDate: 2014-01-09T05:05:21.307127-05:
      DOI: 10.1002/ps.3690
       
  • The occurrence and abundance of two alien eucalypt psyllids in apple
           orchards
    • Authors: Rocío Rosa García; Aitor Somoano, Aranzazu Moreno, Daniel Burckhardt, Dalva Luiz de Queiroz, Marcos Miñarro
      Pages: n/a - n/a
      Abstract: BACKGROUND The arrival of alien insects is frequently associated with the introduction of alien plants. Two exotic Psylloidea native to Australia [Ctenarytaina eucalypti (Maskell, 1890) and Ctenarytaina spatulata Taylor, 1997] were recorded during a two‐year survey in five apple orchards located in Asturias, on the northern coast of Spain. Both species develop on Eucalyptus, but our results suggest that the adults feed also on apple. RESULTS The captures of adult Ctenarytaina, particularly C. spatulata (2191 individuals vs 100 of C. eucalypti) were higher than those of the psyllids that develop on apple. Both species occurred in all sites, including those most distant from the eucalypt plantations. Their abundance peaks matched with two crucial periods in the apple tree cycle: sprouting and leaf drop. The hypothesis that the adult eucalypt psyllids feed on apple is supported by the presence of a phytoplasma, the causal agent of the apple proliferation disease, in one specimen of each species. This phytoplasma can be only acquired after feeding on an infected apple tree. This is the first report of continuous captures of these psyllids in apple orchards. CONCLUSIONS This study suggests that adults of the two Ctenarytaina species feed in apple orchards in Asturias. © 2013 Society of Chemical Industry
      PubDate: 2014-01-07T05:05:26.55757-05:0
      DOI: 10.1002/ps.3701
       
  • Towards area‐wide control of Bactrocera invadens: prospects of the
           sterile insect technique and molecular entomology
    • Authors: Christian E Ogaugwu
      Pages: n/a - n/a
      Abstract: It is 10 years since the first detection of the invader fruit fly, Bactrocera invadens, in sub‐Saharan Africa. The pest continues to hamper fruit production and create barriers to trade. Strategies currently employed to control B. invadens are insufficient, and more effective area‐wide strategies are needed. The sterile insect technique and molecular entomology approaches have high potential and could help to bring about effective area‐wide control of the pest if adopted and used as components of area‐wide integrated pest management. © 2013 Society of Chemical Industry
      PubDate: 2014-01-07T04:58:04.672516-05:
      DOI: 10.1002/ps.3691
       
  • The basis for rootstock resilient to Capnodis species: screening for genes
           encoding δ‐endotoxins from Bacillus thuringiensis
    • Authors: Galina Gindin; Zvi Mendel, Bella Levitin, Pradeep Kumar, Tal Levi, Preeti Shahi, Vadim Khasdan, Dan Weinthal, Tatiana Kuznetsova, Monica Einav, Ariel Kushmaro, Alex Protasov, Arieh Zaritsky, Eitan Ben‐Dov
      Pages: n/a - n/a
      Abstract: BACKGROUND Conventional methods often fail to control the flatheaded borers Capnodis spp., major pests of stone fruit trees; the larvae are protected from insecticides and predation because they feed deep in the roots. A potential solution is transgenic trees producing in their roots toxic compounds such as Cry proteins of Bacillus thuringiensis (Bt). RESULTS Toxicities against Capnodis larvae were demonstrated by exploiting a recently designed artificial larval diet and an available collection of field isolated Bt. An isolate of Bt tenebrionis (Btt) from commercial bioinsecticide (Novodor) displayed LC50 and LC95 values of 3.2 and 164 mg g−1, respectively, against neonates of Capnodis tenebrionis, whereas values of the most toxic field isolate K‐7 were 1.9 and 25.6 mg g−1 respectively. Weights of surviving larvae after 1 month on diets containing low concentrations of K‐7 (0.1–1.0 mg g−1) were lower than on Btt or untreated larvae. K‐7 was also toxic against larvae of C. cariosa and C. miliaris and found to harbour genes encoding Cry9Ea‐like and Cry23Aa/Cry37Aa binary toxins. CONCLUSION Larvae of Capnodis spp. are susceptible to Bt Cry toxins. Expressing cry genes active against these pests thus seems a feasible solution towards production of transgenic rootstock trees resilient to the pest. © 2013 Society of Chemical Industry
      PubDate: 2014-01-02T05:24:13.031271-05:
      DOI: 10.1002/ps.3694
       
  • Seed treatments to control seedborne fungal pathogens of vegetable crops
    • Authors: Valeria Mancini; Gianfranco Romanazzi
      Pages: n/a - n/a
      Abstract: Vegetable crops are frequently infected by fungal pathogens, which can include seedborne fungi. In such cases, the pathogen is already present within or on the seed surface, and can thus cause seed rot and seedling damping‐off. Treatment of vegetable seeds has been shown to prevent plant disease epidemics caused by seedborne fungal pathogens. Furthermore, seed treatments can be useful in reducing the amounts of pesticides required to manage a disease, because effective seed treatments can eliminate the need for foliar application of fungicides later in the season. Although the application of fungicides is almost always effective, their non‐target environmental impact and the development of pathogen resistance have led to the search for alternative methods, especially in the past few years. Physical treatments that have already been used in the past and treatments with biopesticides, such as plant extracts, natural compounds and biocontrol agents, have proved to be effective in controlling seedborne pathogens. These have been applied alone or in combination, and they are widely used owing to their broad spectrum in terms of disease control and production yield. In this review, the effectiveness of different seed treatments against the main seedborne pathogens of some important vegetable crops is critically discussed. © 2013 Society of Chemical Industry
      PubDate: 2013-12-30T09:13:32.863782-05:
      DOI: 10.1002/ps.3693
       
  • Use of acoustics to deter bark beetles from entering tree material
    • Authors: Nicholas C Aflitto; Richard W Hofstetter
      Pages: n/a - n/a
      Abstract: Background Acoustic technology is a potential tool to protect wood materials and eventually live trees from colonization by bark beetles. Bark beetles such as the southern pine beetle Dendroctonus frontalis, western pine beetle D. brevicomis, and pine engraver Ips pini (Coleoptera: Curculionidae) use chemical and acoustic cues to communicate and to locate potential mates and host trees. In this study we tested the efficacy of sound treatments on D. frontalis, D. brevicomis, and I. pini entry into tree materials. Results Acoustic treatments significantly influenced whether beetles entered pine logs in the laboratory. Playback of artificial sounds reduced D. brevicomis entry into logs, and playback of stress call sounds reduced D. frontalis entry into logs. Sound treatments had no effect on I. pini entry into logs. Conclusion The reduction of bark beetle entry into logs using particular acoustic treatments indicates that sound could be used as a viable management tool.
      PubDate: 2013-12-28T08:29:04.462612-05:
      DOI: 10.1002/ps.3720
       
  • Desiccation and cold storage of Galleria mellonella cadavers and
           effects on in vivo production of Steinernema carpocapsae
    • Authors: Xin Wang; Huan Wang, Qing‐zhou Feng, Xi‐yang Cui, Ri‐yue Liu, Yan‐bo Sun, Guo‐chao Li, Hao Tan, Dong‐min Song, Wen Liu, Wei‐bin Ruan, Jeffrey A Harvey
      Pages: n/a - n/a
      Abstract: BACKGROUND Direct application of insect cadavers infected with entomopathogenic nematodes (EPN) can successfully control target pest insects. Little is known about the effects of environmental factors (desiccation and temperature) on the production process for infective juveniles (IJ) in insects. RESULTS We examined the effects of desiccation time and cold storage (6.7 °C) on IJ production of the nematode Steinernema carpocapsae in Galleria mellonella cadavers at 30.8 and 57% humidity. Under desiccation, the IJ yield in cadavers increased gradually and reached a maximum on day 5. IJ yield gradually declined from day 6 onwards and was almost zero by day 15. In general, cold storage at 6.7 °C caused negative effects on IJ production in desiccated cadavers. Approximately 56 h post infection was the time at which nematodes were most sensitive to low temperatures during development in cadavers. Five‐day desiccated cadavers generated higher mortality and more rapid death of Galleria mellonella larvae than using newly (day 0) desiccated cadavers. CONCLUSION This study describe methods of optimizing rearing techniques such as desiccation and cold storage to promote the mass production and application of EPN‐ infected host cadavers for the field control of insect pests. © 2013 Society of Chemical Industry
      PubDate: 2013-12-26T14:44:17.981452-05:
      DOI: 10.1002/ps.3685
       
  • Simplified analysis of glyphosate and aminomethylphosphonic acid in water,
           vegetation and soil by liquid chromatography–tandem mass
           spectrometry
    • Authors: LeEtta J Marek; William C Koskinen
      Pages: n/a - n/a
      Abstract: BACKGROUND There is a need for a simple, fast, efficient and sensitive method for analysis of glyphosate and its degradate aminomethylphosphonic acid (AMPA) in diverse matrices such as water, vegetation and soil. RESULTS Aqueous extracts from water, vegetation and soil were passed through reverse‐phase and cation‐exchange columns and directly injected into a tandem mass spectrometer using only a guard column for separation. Extraction efficiencies from the three matrices were >80% for both glyphosate and AMPA. The method reporting levels (MRLs) for glyphosate in water, vegetation and soil were 3.04 µg L−1, 0.05 mg kg−1 and 0.37 mg kg−1 respectively. AMPA MRLs were 5.06 µg L−1 for water, 0.08 mg kg−1 for vegetation and 0.61 mg kg−1 for soil. CONCLUSIONS A validated, simple and efficient liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for routine analysis of glyphosate and AMPA in water, vegetation and soil that uses minimal sample handling and clean‐up will facilitate the additional environmental research needed to address the continuing concerns related to increasing glyphosate use. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
      PubDate: 2013-12-26T14:43:53.283932-05:
      DOI: 10.1002/ps.3684
       
  • Different metabolic and genetic responses in citrus may explain relative
           susceptibility against Tetranychus urticae
    • Authors: Agut B; Gamir J, Jacas J.A, Hurtado M, Flors V
      Pages: n/a - n/a
      Abstract: Background Life history parameters of the phytophagous spider mite Tetranychus urticae in citrus depend on the rootstock where the cultivar is grafted. To unveil the mechanisms responsible of this effect, we have carried out comparative experiments of T. urticae performance on two citrus rootstocks, the highly T. urticae‐sensitive Cleopatra mandarin and the more tolerant sour orange. Results Sour orange showed reduced leaf damage symptoms, supported lower mite populations and reduced oviposition rates compared to Cleopatra mandarin. Hormonal, metabolomic and gene expression analyses of the main defence pathways suggest a relevant role of the oxylipin and the flavonoid pathways in the response against T. urticae. Sour orange showed an increased activity of the JA pathway which was hardly active in the most susceptible rootstock. Moreover, treatments with the LOX inhibitor Phenidone abolished the enhanced tolerance of sour orange. Therefore, oxylipin‐dependent defence seems to be rootstock‐dependent. The metabolome analysis showed the importance of the flavonoid pathway, which is implicated in the interaction between plants and their environment. Conclusion Our findings suggest that sour orange enhanced tolerance to spider mites can be sustained by a combination of pre‐existing and induced responses standing on high levels of flavonoids and a fast and effective activation of the oxylipin pathway.
      PubDate: 2013-12-26T11:01:55.094263-05:
      DOI: 10.1002/ps.3718
       
  • Combination of endophytic Bacillus and Beauveria for the management of
           Fusarium wilt and fruit borer in tomato
    • Authors: Prabhukarthikeyan S. R; Saravanakumar D, Raguchander T.
      Pages: n/a - n/a
      Abstract: Background Most of the approaches for biocontrol of pests and diseases have used single biocontrol agent as antagonists to a single pest or pathogen. This accounts for inconsistency in the performance of biocontrol agent. So the development of bioformulation possessing mixture of bioagents could be viable option for the management major pests and diseases in crop plants. Results A bioformulation containing mixture of Beauveria bassiana (B2) and Bacillus subtilis (EPC8) was tested against Fusarium wilt and fruit borer in tomato under glasshouse and field conditions. The bioformulation possessing B2 and EPC8 isolates effectively reduced the incidence of Fusarium wilt (Fusarium oxysporum f.sp. lycopersici) and fruit borer (Helicoverpa armigera) as that of chemical pesticides under glasshouse and field conditions compared to individual application of B2 and EPC8 isolates and control treatments. In vitro studies showed the higher larval mortality of H. armigera when fed with B2+EPC8 treated leaves. Further, plants treated with the B2+EPC8 combination showed a greater accumulation of defence enzymes like lipoxygenase, peroxidase and polyphenol oxidase against wilt pathogen and fruit borer pest than the other treatments. Further, a significant increase in growth parameters and yield was observed in tomato plants treated with B2+EPC8 compared to individual bioformulation and untreated control. Conclusion The combined application of Beauveria and Bacillus isolates viz B2 and EPC8 effectively reduced the wilt disease and fruit borer attack in tomato plants. The study offered the possibility of synchronous management of tomato fruit borer pest and wilt disease in a sustainable manner.
      PubDate: 2013-12-26T10:59:33.453624-05:
      DOI: 10.1002/ps.3719
       
  • Host suitability comparison between the MEAM1 and AsiaII 1 cryptic species
           of Bemisia tabaci in cotton growing zones of Pakistan
    • Authors: Muhammad Z. Ahmed; Muhammad Naveed, Muhammad Noor ul Ane, Shun‐Xiang Ren, Paul De Barro, Bao‐Li Qiu
      Pages: n/a - n/a
      Abstract: Background Bemisia tabaci, is a cyptic species complex. In Pakistan, members of the complex, MEAM1 and AsiaII 1 are the predominant species infesting cotton. The biology of the two on cotton, collard, cucumber and tomato was studied. Results In all cases there were significant interactions between species and host. MEAM1 developmental periods did not differ significantly across hosts whereas AsiaII_1 developed more slowly on vegetables than cotton. MEAM1 survival was highest on tomato (53.5 ± 1.1%) while AsiaII_1 survived best on cotton (67.3 ± 11.6%). MEAM1 longevity and fecundity was highest on tomato (14.7 ± 1.7 d and 82.4 ± 9.9 eggs), while AsiaII_1 was highest on cotton (23.7 ± 2.5 d and 135.2 ± 13.6 eggs). The MEAM1 intrinsic rate of increase (rm) on cotton and vegetable was similar (0.08‐0.10) whereas the AsiaII_1 rm on cotton (0.15) was higher than on vegetables (0.11‐0.13). The biology of MEAM1 from Pakistan was compared with published studies; it had a consistently slower rate of development, lower percentage survival, lower adult longevity, longer generation time, lower net reproductive rate and lower rm. Conclusions MEAM1 performed similarly across all hosts whereas AsiaII_1 was better on cotton. The comparison between the Pakistani MEAM1 with published studies suggests that the invasive MEAM1 may have higher performance.
      PubDate: 2013-12-24T12:14:16.144966-05:
      DOI: 10.1002/ps.3716
       
  • Comparative Susceptibility Of Bemisia Tabaci To Imidacloprid In
           Field‐ And Laboratory‐Based Bioassays
    • Authors: SJ Castle; Paul Merten, N Prabhaker
      Pages: n/a - n/a
      Abstract: Background Bemisia tabaci biotype B is a resistance‐prone pest of protected and open agriculture. Systemic uptake bioassays used in resistance monitoring programs have provided important information on susceptibility to neonicotinoid insecticides, but have remained decoupled from field performance. Simultaneous bioassays conducted in field and laboratory settings were compared and related to concentrations of imidacloprid in plant tissue for clearer interpretation of resistance monitoring data. Results Mean mortalities of adult whiteflies confined on cantaloupe leaves field‐treated with three rates of imidacloprid did not exceed 40% in two trials. In contrast, laboratory bioassays conducted on different subsets of the same whitefly populations yielded concentration‐response curves suggestive of susceptibility to imidacloprid in five populations (LC50s from 1.02 to 6.4) relative to a sixth population (LC50 = 13.8). In the field, densities of eggs and nymphs were significantly lower on the imidacloprid‐treated cantaloupes compared to the untreated control, but the margin of control was greater in 2006 than 2007. The potential impact of imidacloprid on whitefly eggs was explored in a greenhouse test that showed egg mortality occurring in both early (1 day) and late (3 day) eggs on cotton leaves systemically treated with imidacloprid. Quantification of imidacloprid residues in cotton leaves used routinely in systemic uptake bioassays revealed concentrations that greatly exceeded concentrations found in the field‐treated cantaloupe leaves, at least at the three highest solution concentrations used for uptake. Conclusion Systemic uptake bioassays have been widely used for monitoring B. tabaci resistance to imidacloprid, but without knowledge of imidacloprid concentrations that occur in test leaves relative to field concentrations. Higher mortality observed in systemic uptake bioassays relative to field‐treated cantaloupes in this study suggest that field rates of imidacloprid are only partially effective against B. tabaci adults, in contrast to systemic uptake bioassays that showed susceptibility to imidacloprid. The discrepancy between field‐ and laboratory‐based mortalities is likely due to extraordinarily high concentrations of imidacloprid that can occur in leaves of systemic uptake bioassays, potentially skewing perception of susceptibility to imidacloprid.
      PubDate: 2013-12-24T12:13:55.808701-05:
      DOI: 10.1002/ps.3717
       
  • Current European Corn Borer, Ostrinia nubilalis, Injury Levels in the
           Northeastern US and the Value of Bt Field Corn
    • Authors: Eric W. Bohnenblust; James A. Breining, John A. Shaffer, Shelby J. Fleischer, Gregory W. Roth, John F. Tooker
      Pages: n/a - n/a
      Abstract: Background Recent evidence indicates that some populations of European corn borer (ECB; Ostrinia nubilalis [Hübner]) have declined to historic lows due to widespread adoption of Bt corn hybrids. To understand current ECB populations in Pennsylvania field corn, we assessed larval damage in Bt and non‐Bt corn hybrids at 29 sites over three years. We also considered the influence of Bt adoption rates, land cover types, and moth activity on levels of ECB damage. Results Bt hybrids reduced ECB damage when compared to non‐Bt, but these differences inconsistently translated to higher yields and, due to higher seed costs, rarely improved profits. We did not detect relationships between land use or Bt adoption and ECB damage rates, but we did find positive relationships between plant damage and captures of Z‐race ECB moths in pheromone traps in the PestWatch network. Conclusions ECB damage levels were generally low and appear to be declining across Pennsylvania. In many locations, farmers may gain greater profits by planting competitive non‐Bt hybrids; however, Bt hybrids remain valuable control options, particularly in the parts of Pennsylvania where ECB populations persist. Moth captures from PestWatch appear to provide insight on where Bt hybrids are most valuable.
      PubDate: 2013-12-14T05:46:54.848029-05:
      DOI: 10.1002/ps.3712
       
  • Resistance to AHAS inhibitor herbicides: Current understanding
    • Authors: Qin Yu; Stephen B Powles
      Pages: n/a - n/a
      Abstract: Acetohydroxyacid synthase (AHAS) inhibitor herbicides currently comprise the largest site‐of‐action group (with 54 active ingredients across five chemistries) and have been widely used in world agriculture since they were first introduced in 1982. Resistance evolution in weeds to AHAS inhibitors has been rapid and identified in populations of many weed species. Often, evolved resistance is associated with point mutations in the target AHAS gene; however non‐target‐site enhanced herbicide metabolism occurs as well. Many AHAS gene resistance mutations can occur and be rapidly enriched due to a high initial resistance gene frequency, simple and dominant genetic inheritance, and lack of major fitness cost of the resistance alleles. Major advances in the elucidation of the crystal structure of the AHAS (Arabidopsis thaliana) catalytic subunit in complex with various AHAS inhibitor herbicides have greatly improved our understanding of the detailed molecular interactions between AHAS, cofactors and herbicides. Compared to target‐site resistance, non‐target‐site resistance to AHAS inhibitor herbicides is less studied and hence less understood. In a few well studied cases, non‐target‐site resistance is due to enhanced rate of herbicide metabolism (metabolic resistance), mimicking that occurring in tolerant crop species and often involving cytochrome P450 monooxyganases. However, the specific herbicide‐metabolising, resistance‐endowing genes are yet to be identified in resistant weed species. The current state of our mechanistic understanding of AHAS inhibitor herbicide resistance is reviewed and outstanding research issues outlined here.
      PubDate: 2013-12-14T03:57:06.002698-05:
      DOI: 10.1002/ps.3710
       
  • Bemisia tabaci nomenclature: Lessons learned
    • Authors: Laura M. Boykin
      Pages: n/a - n/a
      Abstract: Background The nomenclature used within the whitefly research‐community for different putative species within Bemisia tabaci (sensu Russell1) remains highly variable and confused. This was evident by the many different naming schemes researchers were using in their presentations at the 1st International Whitefly Symposium in Kolymbari, Crete, Greece (May 20‐24, 2013). I wanted to try and document how we, as a community, have arrived at such a state of confused nomenclature. This also included an investigation into the nomenclature used in the literature (from 2002 to 2012) using two online search tools (Web of Science and Scirus). Results Nomenclatural data were collected at the 1st International Whitefly Symposium based on oral presentations and posters. There were 17 different names used for the MED species and 12 different names used for the MEAM1 species of the B. tabaci species complex. The investigation into the literature revealed limited uptake of the intermediate names. Conclusion The use of the intermediate names for the various species in the B. tabaci species complex, MED, MEAM1, New World, etc., are not being used by the wider whitefly community. To move forward as a community we must work towards a formal revision of the B. tabaci complex.
      PubDate: 2013-12-14T02:50:27.853845-05:
      DOI: 10.1002/ps.3709
       
  • Potential use of ground based sensor technologies for weed detection
    • Authors: G. G. Peteinatos; M. Weis, D. Andújar, V. Rueda Ayala, R. Gerhards
      Pages: n/a - n/a
      Abstract: Site specific weed management (SSWM) is the part of Precision Agriculture (PA) that tries to effectively control weed infestations with the least economical and environmental burdens. This can be achieved with the aid of ground based or near range sensors in combination with decision rules and precise application technologies. Near range sensor technologies, developed for mounting on a vehicle, have been emerging for PA applications during the last three decades. These technologies focus on identifying plants and measuring their physiological status with the aid of their spectral and morphological characteristics. Cameras, spectrometers, fluorometers and distance sensors are the most prominent sensors for PA applications. The objective of this article is to describe ground based sensors that have the potential to be used for weed detection and measurement of weed infestation level . An overview of current sensor systems is presented, describing their concepts, results that have been achieved, already utilized commercial systems and problems that persist. A perspective for the development of these sensors is given.
      PubDate: 2013-11-06T21:21:52.861181-05:
      DOI: 10.1002/ps.3677
       
  • From integrated pest management to integrated pest eradication:
           technologies and future needs
    • Authors: David M Suckling; Lloyd D Stringer, Andrea EA Stephens, Bill Woods, David G Williams, Greg Baker, Ashraf M El‐Sayed
      Pages: 179 - 189
      Abstract: BACKGROUND With growing globalization and trade, insect incursions are increasing worldwide. A proportion of incursions involve pests of major economic crops (e.g. Mediterranean fruit fly), conservation value (e.g. tramp ants) or health significance (e.g. mosquitoes), and may be the targets of eradication programmes. Historically, such responses have included the use of broad‐spectrum insecticides. However, with increasing public awareness of the negative aspects of pesticides, new environmentally friendly and effective techniques are needed. Here, we review and evaluate a range of selective to broad‐spectrum tactical options for suppression which either have, or show potential for, integration within arthropod eradication programmes. RESULTS Most of the available technologies have their roots in pest management, but higher efficacy is required. Further refinement may be needed for use in eradication. Integration of several tactics is usually needed, as compatible tools can be used simultaneously to target different parts of the pest life cycle. However, not all technologies are fully compatible; for example, the simultaneous use of mass trapping and the sterile insect technique (SIT) may be suboptimal, although sequential application may still be effective. CONCLUSIONS Broad‐spectrum insecticides are generally incompatible with some biologically based technologies such as the SIT, but may be used to reduce the population so that density‐dependent tactics can be used. Several novel technologies with fewer nontarget impacts have been proposed in recent years, and need to be properly evaluated for their applicability to insect eradication. Overall, there are still major gaps in surveillance and selective eradication technologies for most insects. © 2013 Society of Chemical Industry
      PubDate: 2013-11-21T07:05:30.177543-05:
      DOI: 10.1002/ps.3670
       
  • Estimating economic thresholds for site‐specific weed control using
           manual weed counts and sensor technology: An example based on three winter
           wheat trials
    • Authors: Martina Keller; Christoph Gutjahr, Jens Möhring, Martin Weis, Markus Sökefeld, Roland Gerhards
      Pages: 200 - 211
      Abstract: BACKGROUND Precision experimental design uses the natural heterogeneity of agricultural fields and combines sensor technology with linear mixed models to estimate the effect of weeds, soil properties and herbicide on yield. These estimates can be used to derive economic thresholds. Three field trials are presented using the precision experimental design in winter wheat. Weed densities were determined by manual sampling and bi‐spectral cameras, yield and soil properties were mapped. RESULTS Galium aparine, other broad‐leaved weeds and Alopecurus myosuroides reduced yield by 17.5, 1.2 and 12.4 kg ha−1 plant−1 m2 in one trial. The determined thresholds for site‐specific weed control with independently applied herbicides were 4, 48 and 12 plants m−2, respectively. Spring drought reduced yield effects of weeds considerably in one trial, since water became yield limiting. A negative herbicide effect on the crop was negligible, except in one trial, in which the herbicide mixture tended to reduce yield by 0.6 t ha−1. Bi‐spectral cameras for weed counting were of limited use and still need improvement. Nevertheless, large weed patches were correctly identified. CONCLUSION The current paper presents a new approach to conducting field trials and deriving decision rules for weed control in farmers' fields. © 2013 Society of Chemical Industry
      PubDate: 2013-06-18T05:08:39.049376-05:
      DOI: 10.1002/ps.3545
       
  • Improving hybrid seed production in corn
           with glyphosate‐mediated male sterility
    • Authors: Paul C C Feng; Youlin Qi, Tommy Chiu, Martin A Stoecker, Christopher L Schuster, Scott C Johnson, Augustine E Fonseca, Jintai Huang
      Pages: 212 - 218
      Abstract: BACKGROUND Hybrid corn varieties exhibit benefits associated with heterosis and account for most of the corn acreage in the USA. Hybrid seed corn is produced by crossing a female parent which is male‐sterile and therefore incapable of self‐pollination with a male parent as the pollen donor. The majority of hybrid seed corn is produced by mechanical detasseling which involves physically removing the tassel, a process that is laborious and costly. RESULTS Glyphosate‐resistant corn was developed via expression of a glyphosate insensitive 5‐enolpyruvyl‐shikimate 3‐phosphate synthase enzyme (CP4‐EPSPS). Experimentation with molecular expression elements resulted in selective reduction of CP4‐EPSPS expression in male reproductive tissues. The resulting plant demonstrated sterile tassel following glyphosate application with little to no injury to the rest of the plant. Using 14C‐glyphosate as a marker, we also examined the translocation of glyphosate to the tassel via spray application in a track sprayer to simulate field application. The results allowed optimization of spray parameters such as dose, spray timing and target to maximize tassel delivery of glyphosate for efficient sterilization. CONCLUSION The Roundup hybridization system (RHS) is a novel process for hybrid seed production based on glyphosate‐mediated male sterility. RHS replaces mechanical detasseling with glyphosate spray and greatly simplifies the process of hybrid seed corn production. © 2013 Society of Chemical Industry
      PubDate: 2013-05-24T07:32:47.936529-05:
      DOI: 10.1002/ps.3526
       
  • Evaluation of sulfuryl fluoride as a soil fumigant in China
    • Authors: Aocheng Cao; Meixia Guo, Dongdong Yan, Liangang Mao, Qiuxia Wang, Yuan Li, Xiayu Duan, Peisheng Wang
      Pages: 219 - 227
      Abstract: BACKGROUND Root‐knot nematodes and soil‐borne diseases constrain the rapid development of protected agriculture in China, especially while phasing out methyl bromide (MB). The fumigant sulfuryl fluoride (SF) is currently used as an alternative to MB for the disinfestation of buildings and post‐harvest commodities. Our experiments aimed to evaluate a novel application of SF as a soil fumigant in greenhouses in China. RESULTS Dose–response experiments indicated that SF has good efficacy on root‐knot nematodes (Meloidogyne spp.) and moderate activity against Fusarium spp. and weeds (Digitaria sanguinalis (L.) Scop. and Abutilon theophrasti Medicus). The field trials indicates that SF has good efficacy, between 80 and 94%, on Meloidogyne spp., and Fusarium spp. at the rates of 25–50 g m−2 in tomato and cucumber in Beijing and Shandong Province. Marketable yield and plant vigour was not significantly different in SF and MB treatments. SF has lower emissions than MB during the fumigation operation. It is simple to apply, can be used at low temperature, and has a short plant‐back time. SF was found to be an economically feasible alternative to MB for nematode control in China. CONCLUSION SF can be used as a soil fumigant to control root‐knot nematodes and to reduce the levels of key soil pathogens. © 2013 Society of Chemical Industry
      PubDate: 2013-06-06T08:28:01.012956-05:
      DOI: 10.1002/ps.3535
       
  • Structure, bioactivity and implications for environmental remediation of
           complexes comprising the fungicide hexaconazole bound to copper
    • Authors: Jin‐Hao Zhao; Sheng‐Hong Lai, Lu‐Lu Ruan, Jing‐Li Cheng, Cheng‐Xia Tan, Guo‐Nian Zhu
      Pages: 228 - 233
      Abstract: Background In agricultural areas excessive amounts of toxic heavy metals are a growing threat to the environment and human health. Measures should be taken to minimise the risk of adverse health effects. Hence, we investigated the possibilities of hexaconazole (a commercial fungicidal) as a dual‐function ligand that has heavy metal ions chelating and fungicidal activities. Results Metal chelation and fungicidal activities were studied by UV, elemental analysis, IR, thermogravimetric study and biological assays. Results showed that hexaconazole had selective binding capability with Cu2+ over other ions such as Zn2+, Cd2+, Mn2+, Fe2+ and Co2+. Soil leaching experiments showed that soil type had a limited effect on heavy‐metal adsorption by hexaconazole; with decreasing pH, a notable rise of leaching effect was observed, which reached 22%. In addition, this complex exhibit better fungicidal activity against Blumeria graminis than the same dose of hexaconazole. Conclusion This study demonstrates that hexaconazole had notable capabilities to chelate heavy metals as well as excellent fungicidal activity as a metal chelator. Given the mutual influence between pesticides and heavy metals in adsorption–desorption processes, these phenomena must be taken into account if they are to be applied rationally. © 2013 Society of Chemical Industry
      PubDate: 2013-06-18T03:48:32.716905-05:
      DOI: 10.1002/ps.3536
       
  • Two pear accessions evaluated for susceptibility to pear psylla Cacopsylla
           bidens (Šulc) in Israel
    • Authors: Liora Shaltiel‐Harpaz; Victoria Soroker, Rika Kedoshim, Roy Hason, Tamar Sokalsky, Kamel Hatib, Irit Bar‐Ya'akov, Doron Holland
      Pages: 234 - 239
      Abstract: BACKGROUND The pear psylla, Cacopsylla bidens (Šulc), is one of the most damaging pests of commercial pear orchards in Israel. Psylla control is a major obstacle to efficient integrated pest management, necessitating research on cultivars with natural resistance to pear psylla. Recently, two pear accessions (Py.760‐261 and Py.701‐202) from the local Newe Ya'ar fruit tree live collection were identified as having apparent resistance to pear psylla. Our goal was to evaluate the resistance of these two accessions relative to the commercial cultivar Spadona Estiva, and to identify whether the resistance mechanisms in the former interfere with insect colonisation of the plant (antixenosis) or inhibit insect growth, development, reproduction and survival (antibiosis). RESULTS Settlement and development of C. bidens was evaluated under natural conditions (pear orchard), semi‐natural conditions (potted plants), and on detached branches and leaves (laboratory). Our results indicate that the selection Py.760‐261 is 10 times more resistant than Spadona while Py.701‐202 is five times more resistant. CONCLUSIONS The resistance mechanism in both accessions appears to be antibiosis affecting nymph survival. These resistant accessions may be used as rootstock or as a source of resistant genes in breeding programmes. © 2013 Society of Chemical Industry
      PubDate: 2013-07-04T10:26:26.940959-05:
      DOI: 10.1002/ps.3543
       
  • Effects of termiticide exposure on mutual interactions between the treated
           and untreated workers of the Asian subterranean termite Coptotermes
           gestroi
    • Authors: Kok‐Boon Neoh; Ching‐Chen Lee, Chow‐Yang Lee
      Pages: 240 - 244
      Abstract: BACKGROUND Mutual interactions, including reciprocal food sharing and grooming between chlorantraniliprole‐ and fipronil‐treated, and untreated Asian subterranean termites, Coptotermes gestroi (Wasmann), were examined using rubidium as a tracer. Two questions were addressed in this study: (1) After insecticide treatment, does the mutual interaction between termiticide‐treated termites and untreated nestmates increase? (2) Does the nutritional status of both termiticide‐treated termites and untreated nestmates affect the mutual interaction? RESULTS The comparative data suggested that chlorantraniliprole‐treated termites were more regularly attended by untreated termites than the fipronil‐treated termites. Mutual interaction between the chlorantraniliprole‐treated termites and untreated termites was not affected by their nutritional status. A high level of rubidium was present in the reciprocal exchange from fipronil‐treated termites to starved untreated termites, indicating that intoxication induced alimentary or anal fluids served as a food source for starved termites. CONCLUSION The results of the present study indicated that termites exposed to chlorantraniliprole were more likely to cease feeding and then undergo starvation. Thus, the treated termites were subject to intensive reciprocal food exchange and frequent attention from untreated nestmates. In the fipronil treatment, starvation status facilitated the reciprocal food exchange rate from treated termites to starved untreated termites. © 2013 Society of Chemical Industry
      PubDate: 2013-06-14T08:13:16.603833-05:
      DOI: 10.1002/ps.3544
       
  • Simultaneous quantification of alleles E198A and H6Y in the
           β‐tubulin gene conferring benzimidazole resistance in Monilinia
           fructicola using a duplex real‐time (TaqMan) PCR
    • Authors: Jinyan Fan; Yong Luo, Themis J Michailides, Liyun Guo
      Pages: 245 - 251
      Abstract: BACKGROUND The benzimidazole fungicide thiophanate‐methyl is commonly used for the control of brown rot of stone fruits. Low and high levels of resistance to this fungicide have been found in field isolates of the causal pathogen Monilinia fructicola. RESULTS The minor groove binding (MGB) TaqMan probes specific for alleles E198A and H6Y conferring the high and low levels of resistance in the β‐tubulin gene of M. fructicola were designed. A duplex real‐time PCR assay based on these probes was developed for simultaneous quantification of both mutations in a pathogen population. The specificity tests for the primers and probes were conducted using different fungal species of stone and pome fruit pathogens. Similar results were obtained between the duplex real‐time (TaqMan) PCR assay and the conventional method to quantify the frequencies of alleles E198A and H6Y of eight samples from different peach orchards. CONCLUSION The MGB TaqMan probe based duplex real‐time PCR provides a useful tool for simultaneous quantification of both alleles, E198A and H6Y, conferring high and low resistance, and has a potential in monitoring the benzimidazole‐resistance in M. fructicola populations in stone and pome fruit orchards. © 2013 Society of Chemical Industry
      PubDate: 2013-06-17T07:11:12.404052-05:
      DOI: 10.1002/ps.3549
       
  • Herbicidal activity of formulated sorgoleone, a natural product of sorghum
           root exudate
    • Authors: Md Romij Uddin; Sang Un Park, Franck E Dayan, Jong Yeong Pyon
      Pages: 252 - 257
      Abstract: Background The allelochemical sorgoleone, a major component of the hydrophobic root exudates of Sorghum bicolor, was formulated as a wettable powder [4.6 WP] and evaluated as a natural herbicide on several weed and crop species under different growth conditions. Results Formulated sorgoleone [4.6 WP] suppressed germination and shoot growth of weeds, with broadleaf species showing greater susceptibility than grass weed species. Germination and growth of broadleaf weed species were completely suppressed (100%) at 0.2 g a.i. L−1 sorgoleone in a growth chamber study. Post‐emergence applications of the wettable formulation of sorgoleone [4.6 WP] inhibited 20–25% higher growth of weeds than pre‐emergence applications under greenhouse conditions. Broadleaf weeds were more susceptible than grass species to both methods of application. In all studies, growth was suppressed in more than 90% of the broadleaf weeds and two species, in particular, Rumex japonicus and Plantago asiatica, were completely suppressed at 0.4 kg a.i. ha−1 sorgoleone. The crop species, on the other hand, were much more tolerant to sorgoleone, with 30% inhibition, at most, at the highest rate of 0.4 kg a.i. ha−1 sorgoleone. Conclusion The results of this study reveal that sorgoleone, after formulation as a WP, is more effective in inhibiting weed growth, and crop species are tolerant to it. The strong weed suppressive ability of formulated sorgoleone therefore offers interesting possibilities as an effective natural environment‐friendly approach for weed management. © 2013 Society of Chemical Industry
      PubDate: 2013-06-20T04:35:54.389831-05:
      DOI: 10.1002/ps.3550
       
  • Integrated biological and chemical control of rice sheath blight by
           Bacillus subtilis NJ‐18 and jinggangmycin
    • Authors: Di Peng; Shandong Li, Jianxin Wang, Changjun Chen, Mingguo Zhou
      Pages: 258 - 263
      Abstract: BACKGROUND Sheath blight caused by Rhizoctonia solani Kühn is a major disease of rice that greatly reduces yield and grain quality and jinggangmycin is the most widely used fungicide to control this disease in China. Bacillus subtilis NJ‐18 has broad antimicrobial activity to many phytopathogenic bacteria and fungi; it is especially effective against Rhizoctonia solani. Laboratory, greenhouse and field tests were conducted to determine the effect of combining the biological control agent Bacillus subtilis NJ‐18 with the fungicide jinggangmycin for control of rice sheath blight. RESULTS Growth of NJ‐18 in vitro was not affected by jinggangmycin. In a greenhouse experiment, disease control was greater with a mixture of NJ‐18 and jinggangmycin than with either alone; a mixture of NJ‐18 at 108 cfu mL−1 and jinggangmycin at 50 or 100 mg L−1 reduced lesion length by 35% and 20%, respectively, and the combinations showed a synergistic action. In three field trials, disease control was significantly greater with a mixture of NJ‐18 at 108 cfu mL−1 and jinggangmycin at 75 or 150 g a.i. ha−1 than with either component alone. CONCLUSION The results of the study indicate that, when Bacillus subtilis NJ‐18 strain was combined with jinggangmycin, there was an increased suppression of rice sheath blight, and thus could provide an alternative disease control option. © 2013 Society of Chemical Industry
      PubDate: 2013-06-18T05:08:44.065269-05:
      DOI: 10.1002/ps.3551
       
  • An improved bioassay facilitates the screening of repellents against cat
           flea, Ctenocephalides felis (Siphonaptera: Pulicidae)
    • Authors: Li‐Chong Su; Chin‐Gi Huang, Shang‐Tzen Chang, Shu‐Hui Yang, Shan‐hui Hsu, Wen‐Jer Wu, Rong‐Nan Huang
      Pages: 264 - 270
      Abstract: BACKGROUND Repellents are a common method for preventing flea bites, making an effective system for flea repellent screening advantageous. We describe an improved technique to facilitate repellent activity screening of numerous plant‐based Ctenocephalides felis (cat flea) repellents. RESULTS Two long strips of filter paper were impregnated with test compounds (dissolved in ethanol) and ethanol only, respectively. After drying, the two filter papers were glued together along the long side and inserted into a glass tube containing non‐fed cat fleas. The distribution of cat fleas in each half of the filter paper was recorded after 30 min to calculate repellency. Results showed that the essential oil of Cinnamomum osmophloeum (from leaf), Taiwania cryptomerioides (from heartwood) and Plectranthus amboinicus (from leaf) exhibits repellent activity against cat fleas in a dose dependent manner. Moreover, the repellent activities against cat fleas of 2% trans‐cinnamaldehyde (the main constituent of Ci. osmophloeum essential oil) and 0.5% thymol (the main constituent of P. amboinicus essential oil) are 97.6% and 90.6%, and can persist for up to 4 and 8 h, respectively. These results are comparable to those of 15% DEET. CONCLUSION The proposed screening technique can facilitate the pre‐screening of numerous flea repellents for further evaluation on animal or human subjects. © 2013 Society of Chemical Industry
      PubDate: 2013-06-25T07:57:22.13347-05:0
      DOI: 10.1002/ps.3554
       
  • Ant control efficacy of pyrethroids and fipronil on outdoor concrete
           surfaces
    • Authors: Weiying Jiang; Andrew Soeprono, Michael K Rust, Jay Gan
      Pages: 271 - 277
      Abstract: BACKGROUND Urban and residential concrete surfaces are often treated with pesticides to control ants. Run‐off from irrigation/rainfall can remove pesticides from concrete and contaminate urban waterways. Recent regulations and mitigations in regions such as California aim to reduce insecticide run‐off (e.g. pyrethroids), but are often proposed without adequate consideration of their impact on ant control efficacy. METHODS We carried out an outdoor study with a side‐by‐side comparison between pesticide run‐off potential and residual ant toxicity after exposing treated concrete to summer conditions and simulated precipitations. RESULTS Treatments with bifenthrin, permethrin or fipronil all showed fast ant knockdown initially, and over 50% of ants were killed within 16 h after 1‐min contact with the treated surfaces. Shorter ant median lethal time (LT50) was observed on concrete treated with over‐the‐counter (OTC) granule/dust formulations than OTC liquid or professional formulations. However, the treated surfaces rapidly lost ant control efficacy after outdoor exposure and repeated precipitations. Except for OTC solid permethrin treatment, the ant toxicity disappeared after 20 days for all other formulation treatments. In contrast, pesticides were detected in run‐off water from simulated precipitations even 89 days after the treatment, with levels above 0.5 µg L−1 for bifenthrin, 30 µg L−1 for permethrin and 0.15 µg L−1 for fipronil. Pyrethroid run‐offs from OTC solid formulations were >10 times higher than the other two formulations. CONCLUSIONS The results suggested viable options for run‐off mitigation include decreasing use on concrete such as using crack/spot treatments instead of broadcast applications, limiting pesticide use on hardscapes away from water contact, and avoiding using dust/granule formulations on hardscapes. © 2013 Society of Chemical Industry
      PubDate: 2013-06-27T09:55:54.72786-05:0
      DOI: 10.1002/ps.3555
       
  • Identification of a new PSII target site psbA mutation leading to D1 amino
           acid Leu218Val exchange in the Chenopodium album D1 protein and comparison
           to cross‐resistance profiles of known modifications at positions 251
           and 264
    • Authors: Heike Thiel; Mark Varrelmann
      Pages: 278 - 285
      Abstract: BACKGROUND Resistance of Chenopodium album to triazinones and triazines can be caused by two amino acid exchanges, serine‐264‐glycine (Ser264Gly) and alanine‐251‐valine (Ala251Val), in the chloroplast D1 protein. This paper describes the identification of a biotype with a leucine‐218‐valine (Leu218Val) switch found in German sugar beet fields with unsatisfactory weed control. A greenhouse experiment has been performed to compare the resistance profile of the newly identified biotype with biotypes that carry the Ser264Gly and Ala251Val mutations. RESULTS Application rate–response curves obtained from the greenhouse experiment showed that the Leu218Val exchange induced significant resistance against the triazinones but not against terbuthylazine. The level of resistance against the triazinones was higher in the Ser264Gly and Ala251Val biotypes compared with the Leu218Val biotype. All biotypes tested were more resistant to metribuzin than to metamitron. Following terbuthylazine treatment, Ser264Gly displayed a high level of resistance, Ala251Val showed moderate resistance. A PCR‐RFLP assay for Ser264Gly has been extended to include detection of Ala251Val and Leu218Val mutations. CONCLUSION The D1 Leu218Val substitution in C. album confers significant resistance to triazinones. This suggests that Leu218Val is involved in the binding of triazinones. First establishment of the resistance profiles of the three psbA mutations suggests that these mutations have been independently selected. © 2013 Society of Chemical Industry
      PubDate: 2013-07-01T08:32:14.884165-05:
      DOI: 10.1002/ps.3556
       
  • Lactones 43. New biologically active lactones: β‐cyclocitral
           derivatives
    • Authors: Marcelina Mazur; Witold Gładkowski, Magdalena Podkowik, Jacek Bania, Jan Nawrot, Agata Białońska, Czesław Wawrzeńczyk
      Pages: 286 - 294
      Abstract: BACKGROUND In our previous studies bicyclic γ‐lactones with cyclohexane ring exhibited high antifeedant activity against storage pests. The activity was correlated with the type and number of substituents in the cyclohexane ring. One of the most potent group of antifeedant agents was δ‐iodo‐γ‐lactones. RESULTS We present the synthesis of new bicyclic γ‐lactones with the cyclohexane ring containing different halogen atoms. To determine the impact of halogen type on biological activity the lactone without halogen atom was also synthesized. The lactones were tested for their antifeedant activity toward the granary weevil beetle (Sitophilus granarius L.), the khapra beetle (Trogoderma granarium Everts) and the confused flour beetle (Tribolium confusum Du Val.). The results of the tests proved that the highest activity was observed for chlorolactone (7) towards larvae and adults of Tribolium confusum. Antibacterial activity of new lactones was also evaluated. Lactone without halogen atom (8) was active against Staphylococcus aureus and Listeria monocytogenes. CONCLUSIONS Studies on the biological activity of synthesised lactones revealed high selectivity towards insect pests as well as bacterial strains. Only the halolactones exhibited significant antifeedant activity. In contrast, antibacterial activity was shown only by the lactone (8) without halogen. © 2013 Society of Chemical Industry
      PubDate: 2013-07-01T08:39:01.683608-05:
      DOI: 10.1002/ps.3557
       
  • Multiple glutathione S‐transferase genes: identification and
           expression in oriental fruit fly, Bactrocera dorsalis
    • Authors: Fei Hu; Wei Dou, Jing‐Jing Wang, Fu‐Xian Jia, Jin‐Jun Wang
      Pages: 295 - 303
      Abstract: Background The oriental fruit fly, Bactrocera dorsalis (Hendel), is widely distributed in Asia–Pacific regions, where it is a serious pest of a wide range of tropical and subtropical fruit and vegetable crops. In this study, 17 cDNA encoding glutathione S‐transferases (GSTs) in B. dorsalis were sequenced and characterised. Results Phylogenetic analysis revealed that 16 GSTs belonged to five different cytosolic classes, including four in delta, eight in epsilon, two in omega, one in theta, and one in zeta. The remaining GST (BdGSTu1) was unclassified. RT‐qPCR assay showed that the relative expression levels of five GST genes were significantly higher in larval stages than in adulthood. Tissue‐specific expression analysis found that BdGSTe3, BdGSTe9 and BdGSTd5 were expressed highly in the midgut, BdGSTe4, BdGSTe6, BdGSTd6 and BdGSTz2 were higher in the fat body, and six GSTs were higher in Malpighian tubules. RT‐qPCR confirmed that the expressions of nine GST genes were increased by malathion exposure at various times and doses, while BdGSTe4, BdGSTe9 and BdGSTt1 were increased by β‐cypermethrin exposure. Conclusion The increases in GST gene expression levels after malathion and β‐cypermethrin exposure in B. dorsalis might increase the ability of this species to detoxify other insecticides and xenobiotics. © 2013 Society of Chemical Industry
      PubDate: 2013-06-27T06:15:22.507049-05:
      DOI: 10.1002/ps.3558
       
  • Automated locomotor activity monitoring as a quality control assay for
           mass‐reared tephritid flies
    • Authors: Bernard C Dominiak; Benjamin G Fanson, Samuel R Collins, Phillip W Taylor
      Pages: 304 - 309
      Abstract: BACKGROUND The Sterile Insect Technique (SIT) requires vast numbers of consistently high quality insects to be produced over long periods. Quality control (QC) procedures are critical to effective SIT, both providing quality assurance and warning of operational deficiencies. We here present a potential new QC assay for mass rearing of Queensland fruit flies (Bactrocera tryoni Froggatt) for SIT; locomotor activity monitoring. We investigated whether automated locomotor activity monitors (LAMs) that simply detect how often a fly passes an infrared sensor in a glass tube might provide similar insights but with much greater economy. RESULTS Activity levels were generally lower for females than for males, and declined over five days in the monitor for both sexes. Female activity levels were not affected by irradiation, but males irradiated at 60 or 70 Gy had reduced activity levels compared with unirradiated controls. We also found some evidence that mild heat shock of pupae results in adults with reduced activity. CONCLUSION LAM offers a convenient, effective and economical assay to probe such changes. © 2013 Society of Chemical Industry
      PubDate: 2013-07-11T07:24:30.317728-05:
      DOI: 10.1002/ps.3559
       
  • Multi‐generational effects of rice harboring Bph15 on brown
           planthopper, Nilaparvata lugens
    • Authors: Jie Li; Keke Shang, Jia Liu, Tingru Jiang, Dingbang Hu, Hongxia Hua
      Pages: 310 - 317
      Abstract: BACKGROUND The brown planthopper (BPH), Nilaparvata lugens, is one of the most devastating rice pests in Asia. Resistant cultivars are an effective way of managing BPH. Bph15 is a BPH resistance gene and has been introgressed into rice variety Minghui 63 (MH63). The multi‐generational effects of rice line MH63::15 (harboring Bph15) on BPH were investigated and compared with its parental line MH63. RESULTS U‐test analysis indicated that, over seven generations, the developmental duration of BPH nymphs was significantly prolonged by MH63::15. The results of a two‐way analysis indicated that, over seven generations, MH63::15 had significant negative effects on the hatchability, emergence rate, copulation rate, weight of adults and fecundity of BPH, but no significant effects on the survival rate of nymphs or female ratio of BPH. In addition, the development of ovary was significantly retarded by MH63::15, and the expression of oogenesis genes were either down‐regulated (three genes) or up‐regulated (one genes) by MH63::15 compared with MH63. CONCLUSIONS After being reared continuously on MH63::15 for seven generations, most of the life parameters of BPH were negatively affected by MH63::15, especially fecundity and ovary development. These results indicate that MH63::15 rice has potential for use in the control of BPH. © 2013 Society of Chemical Industry
      PubDate: 2013-07-09T04:39:00.016568-05:
      DOI: 10.1002/ps.3560
       
  • Metalized polyethylene mulch to repel Asian citrus psyllid, slow spread of
           huanglongbing and improve growth of new citrus plantings
    • Authors: Scott D. Croxton; Philip A. Stansly
      Pages: 318 - 323
      Abstract: BACKGROUND Greening or huanglongbing (HLB) is a debilitating disease of citrus caused by Candidatus Liberibactor asiaticus and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. HLB now occurs worldwide in all major citrus growing regions except the Mediterranean and Australia. Management relies principally on insecticidal control of the ACP vector, but is insufficient, even for young trees which are most susceptible to the disease. We tested the ability of metalized polyethylene mulch to repel adult ACP as well as effects on incidence of HLB and early tree growth. RESULTS Metalized mulch significantly reduced ACP populations and HLB incidence compared to whiteface mulch or bare ground. In addition, metalized mulch, together with the associated drip irrigation and fertigation system, increased soil moisture, reduced weed pressure, and increased tree growth rate. CONCLUSION Metalized mulch slows spread of ACP and therefore HLB pressure on young citrus trees. Metalized mulch can thereby augment current control measures for young trees based primarily on systemic insecticides. Additional costs could be compensated for by increased tree growth rate which would shorten time to crop profitability. These advantages make a compelling case for large‐scale trials using metalized mulch in young citrus plantings threatened by HLB. © 2013 Society of Chemical Industry
      PubDate: 2013-07-17T02:50:16.954712-05:
      DOI: 10.1002/ps.3566
       
  • A four‐component synthetic attractant for Drosophila suzukii
           (Diptera: Drosophilidae) isolated from fermented bait headspace
    • Authors: Dong H Cha; Todd Adams, Christopher T Werle, Blair J Sampson, John J Adamczyk, Helmuth Rogg, Peter J Landolt
      Pages: 324 - 331
      Abstract: BACKGROUND A mixture of wine and vinegar is more attractive than wine or vinegar to spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), and ethanol and acetic acid are considered key to that attractiveness. In addition to ethanol and acetic acid, 13 other wine and vinegar volatiles are antennally active to D. suzukii and might be involved in food finding. RESULTS Out of the 13 antennally active chemicals, acetoin, ethyl lactate and methionol increased fly response to a mixture of acetic acid and ethanol in field trapping experiments. A five‐component blend of acetic acid, ethanol, acetoin, ethyl lactate and methionol was as attractive as the starting mixture of wine and vinegar in field tests conducted in the states of Oregon and Mississippi. Subtracting ethyl lactate from the five‐component blend did not reduce the captures of flies in the trap. However, subtracting any other compound from the blend significantly reduced the numbers of flies captured. CONCLUSION These results indicate that acetic acid, ethanol, acetoin and methionol are key olfactory cues for D. suzukii when attracted to wine and vinegar, which may be food‐finding behavior leading flies to fermenting fruit in nature. It is anticipated that this four‐component blend can be used as a highly attractive chemical lure for detection and management of D. suzukii. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
      PubDate: 2013-07-22T05:37:19.767912-05:
      DOI: 10.1002/ps.3568
       
  • Clearance of ingested neonicotinoid pesticide (imidacloprid) in honey bees
           (Apis mellifera) and bumblebees (Bombus terrestris)
    • Authors: James E Cresswell; François‐Xavier L Robert, Hannah Florance, Nicholas Smirnoff
      Pages: 332 - 337
      Abstract: BACKGROUND Bees in agricultural landscapes are exposed to dietary pesticides such as imidacloprid when they feed from treated mass‐flowering crops. Concern about the consequent impact on bees makes it important to understand their resilience. In the laboratory, the authors therefore fed adult worker bees on dosed syrup (125 μg L−1 of imidacloprid, or 98 μg kg−1) either continuously or as a pulsed exposure and measured their behaviour (feeding and locomotory activity) and whole‐body residues. RESULTS On dosed syrup, honey bees maintained much lower bodily levels of imidacloprid than bumblebees (
      PubDate: 2013-08-09T09:15:35.290654-05:
      DOI: 10.1002/ps.3569
       
  • Activity of chlorantraniliprole and thiamethoxam seed treatments on life
           stages of the rice water weevil as affected by the distribution of
           insecticides in rice plants
    • Authors: Srinivas K Lanka; Michael J Stout, Julien M Beuzelin, James A Ottea
      Pages: 338 - 344
      Abstract: BACKGROUND The systemic insecticides chlorantraniliprole (CAP) and thiamethoxam (TMX), applied to rice as seed treatments, may affect multiple life stages of the rice water weevil, Lissorhoptrus oryzophilus. Effects of CAP and TMX on adult survival, egg‐laying and first‐ and late‐instar survivals were determined by infesting plants treated as seeds with different rates of insecticides. The biological activity was related to insecticidal concentrations in leaves, shoots and roots. RESULTS CAP did not affect adult survival but decreased egg numbers and reduced the survival of the first and late instars. The greatest reduction in weevil population occurred in late instars feeding on roots. In contrast, TMX reduced adult survival and egg and larval numbers. The high biological activity of CAP on root‐feeding stages was consistent with the accumulation of CAP in roots, whereas in TMX‐treated plants the high activity on adults correlated with high concentrations of TMX in leaves and stems. CONCLUSIONS The differential activity of insecticides on adults suggests poor inherent potency of CAP as an adulticide and/or its limited systemicity in foliage. The distribution of insecticide in specific plant parts can be attributed to the different physicochemical properties of CAP and TMX. The field implications of this research on management of L. oryzophilus are discussed. © 2013 Society of Chemical Industry
      PubDate: 2013-07-29T08:06:31.677975-05:
      DOI: 10.1002/ps.3570
       
  • Environmental fungicides and triazole resistance in Aspergillus
    • Abstract: Fungal diseases are problematic in both human health and agriculture. Treatment options are limited and resistance may emerge. The relatively recent recognition of triazole resistance in Aspergillus fumigatus has prompted questioning of the origin of resistance. While multiple mechanisms are described in clinical isolates from triazole‐treated patients, some de novo resistance is also recognised, especially attributable to TR34/L98H. Such strains probably arose in the environment, and, indeed, multiple studies have now demonstrated TR34/L98H triazole resistance strains of A. fumigatus from soil. Docking and other in vitro studies are consistent with environmental resistance induction through exposure to certain triazole fungicides, notably difenoconazole, propiconazole, epoxiconazole, bromuconazole and tebuconazole. This article addresses the potential implications of this issue for both human health and food security. © 2013 Society of Chemical Industry
       
  • Quantification of Fusarium oxysporum in fumigated soils by a newly
           developed real‐time PCR assay to assess the efficacy of fumigants
           for Fusarium wilt disease in strawberry plants
    • Abstract: Background Two soil fumigants, chloropicrin (CP) and dimethyl disulfide (DMDS), were used to control Fusarium wilt disease (FWD) which caused large economic losses on strawberries. The fumigants were evaluated alone and in combination in a laboratory study and in strawberry greenhouses. Results Laboratory tests found that the combinations of CP and DMDS indicated a positive synergistic activity on Fusarium oxysporum. A newly developed quantitative assay for F. oxysporum involving real‐time PCR was used successfully for evaluating F. oxysporum control by the fumigants; it provided similar results as the selective medium but was less time consuming and less labor intensive. Greenhouse trials revealed that the combination of CP and DMDS successfully suppressed the incidence of FWD and sharply reduced the population density of F. oxysporum, which significantly increased the fruit branch number and maintained a good strawberry yield, higher than MB treatment. All of the treatments provided significantly better results than the non‐treated control. Conclusion This study confirms that the newly developed real‐time PCR quantitative assay for F. oxysporum was suitable for the control‐efficacy evaluation of soil fumigants and that the novel fumigant combination of CP and DMDS offers a promising effective alternative to methyl bromide for the control of F. oxysporum in strawberry greenhouses.
       
 
 
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