A method for the estimation of 1,2-dibromoethane in vegetables

Residues of 1,2-dibromoethane (EDB) were readily estimated in treated vegetables down to levels of 0.2 mg/kg. Clean-up was effected by steam distillation into a toluene trap. This was followed by X-ray fluorescence determination of the collected EDB in the toluene. Good recoveries of added EDB were obtained at 0.5, 2, 5 and 20 mg/kg in cucumbers, pumpkins and zucchinis.     

Residual fumigant effect of 1,2-dibromoethane (EDB) in fumigations against queensland fruit fly,Dacus tryoni (froggatt), infestations in mangoes

A residual fumigant effect is demonstrated for fruit held 1 to 3 days within its cardboard carton after fumigation with 1,2-dibromoethane (EDB). This residual fumigant effect reduces significantly the dosage required for a specified level of control when compared with that required for fruit removed from the carton immediately after airing when fumigation is completed. The effect is due to the slow release of gas sorbed during fumigation and to the slow dispersion of this gas from the carton.     

A study of 1,2-dibromoethane residues in wheat and milled products

A method is described for determining residues of 1,2-dibromoethane (EDB) in milled wheat products. The residues are first extracted with benzene, then recovered azeotropically for reaction with alkali and subsequent determination of liberated bromide ion by a Volhard titration. Freshly milled flours from wheat fumigated with 65.0 and 325 mg EDB/litre at 37°C were found to contain 10.6 to 39.4 mg EDB/kg and the bran contained from 51.4 to 153 mg EDB/kg.     

Influence of liquid manure application method on weed control in spring cereals

Summary Injection of liquid manure (slurry) into the soil is an alternative to the traditional surface application. By the injection method, it is possible to place nutrients closer to the crop sown, thus offering the crop a competitive advantage over weeds. This study compares the response in crop yield, weed density and weed biomass to injection vs. surface application of liquid manure through three growing seasons in barley and oats. The manure applications were combined with treatments of weed harrowing or herbicide spraying or no treatment at all. The levels of weed control and crop yield obtained by harrowing and herbicides were larger when slurry was injected compared with surface application. Without any weed control treatments, the injection method decreased the final weed biomass in barley. The influence of nutrient injection on yield and weed control seemed to be modulated by the time of emergence and the early growth rate of the crop relative to weeds. Thus, because of its early root growth and development, barley responded more quickly to the injection treatment than oats. Consequently, barley became a more competitive crop.     

PROGEB—a model-aided forecasting service for pest management in cereals and potatoes1

PROGEB integrates forecasting models for the main pests of potatoes and cereals in Germany: PHYTEB for Phytophthora infestans, SIMLEP for Leptinotarsa decemlineata, SIMCERC for Pseudocercosporella herpotrichoides, SIMERY for Erysiphe graminis. All models follow the same philosophy, and have been implemented on PCs following a uniform design. The system is illustrated by the example of P. infestans control.     

Efficacy of vaporised ethyl formate/carbon dioxide formulation against stored‐grain insects: effect of fumigant concentration,exposure time and two grain temperatures

BACKGROUND: The ethyl formate/carbon dioxide (CO₂) formulation Vapormate? is a rapid‐acting fumigant being developed for the control of stored‐grain insects. The effects have been investigated of concentration, exposure times of 1, 3, 24 and 72 h and two grain temperatures, 15 and 25 °C, on its efficacy against mixed‐stage cultures of Sitophilus oryzae (L.) Tribolium castaneum (Herbst) and strongly phosphine‐resistant Rhyzopertha dominica (F.) strain QRD569. RESULTS: High mortalities (≥92%) of mixed‐stage cultures of all three species were obtained when grain was fumigated with the formulation (193 g m^?3 ethyl formate) for 1 h. Complete control of R. dominica QRD569 and T. castaneum was achieved with 63 and 76 g m^?3 ethyl formate respectively, with exposure for 24 h, whereas mean mortality of S. oryzae was 86% under the same conditions. Mortalities of S. oryzae juvenile stages were significantly lower than adults under the conditions tested, which was due to pronounced tolerance of mid‐stage pupae to the fumigant. Reducing grain temperature from 25 to 15 °C had no effect on insect mortality. CONCLUSION: Ethyl formate/CO₂ formulation is highly effective against stored‐grain insects over a range of concentrations and exposure times. Efficacious fumigations were conducted in as little as 1 h, and a strongly phosphine‐resistant R. dominica strain was readily controlled with the fumigant. Copyright © 2009 CSIRO, Australia. Published by John Wiley & Sons, Ltd     

Estimation of thresholds for weed control in Australian cereals

A non-linear model relating crop yield to the density of weeds was fitted to nine Victorian weeds to evaluate their competitive abilities. The weeds were: Acroptilon repens (L.) DC. (creeping knapweed), Chondrilla juncea L. (Skeleton weed, Raphanus raphanistrum L. (Wild radish), lolium rigidum Gaud. (Annual ryegrass), Lithospermum arvense L. (White iron weed), Brassica tournefortii Gouan (Wild turnip), Lamium amplexicaule L. (Deadnettle), Fumaria parviflora Lam. (White fumitory) and Amsinckia hispida (Ruiz & Pav.) I.M. Johnston (Amsinckia). Where more than one experiment was available for a weed, the net return for a herbicide treatment over a range of weed densities was calculated to obtain the economic threshold density. Generally, the economic threshold densities within a weed species were the same order of magnitude, except for the perennial Chondrilla Juncea L., For this species data were collected in years of contrasting rainfall. The model used here is discussed in view of the threshold approach currently used in continental Europe.     

Microwave treatment for pest control: the case of Rhynchophorus ferrugineus in Phoenix canariensis

Rhynchophorus ferrugineus (red palm weevil) is currently one of the major threats to palms in the Mediterranean area. No single technique developed up to now seems able to completely eradicate this pest. This paper introduces microwave treatment as an effective tool to help the control of this insect; the effect of microwave radiation on palm tissues and on the curculionid is described and discussed. The main advantage of microwaves is their eco‐compatibility, and preliminary results of their application to Rhynchophorus ferrugineus control are very promising.     

高温控温处理防治害虫的研究及应用进展

高温控温处理方法具有环境友好、杀虫效率高、无残留等优点,已经用于商品闪热处理、检疫热处理防治害虫。但是高温控温处理可能会存在破坏商品质量,热量分布不均导致热利用效率较低,不能有效杀灭商品以及工厂中的害虫等问题。本文综述了高温控温处理方法在害虫防治中的研究及应用进展,讨论了高温控温处理所面临的问题以及今后发展方向。     

Characteristics of pyrethroids for insect pest control in agriculture

Pyrethroid insecticides are characterised by high knockdown and lethal activity, a wide spectrum, good residual activity, together with repellent and antifeeding activity. With these characteristics, pyrethroid insecticides have become widely used for plant protection. Their major use has been for the control of bollworms and leafworms in cotton but they have also achieved widespread use for controlling various species of lepidopterous pests in fruits and vegetables, aphids in cereals, and many other minor outlets. Although the early synthetic pyrethroids suffered from a lack of activity against mites and soil pests, later additions, such as fenpropathrin, have combined high acaricidal activity with insecticidal activity and further pyrethroids are being introduced for use in soil. The extent of pyrethroid use has increased progressively since the first of the ‘photostable’ pyrethroids was registered. In 1986, the market share of pyrethroids reached 25 % of the total insecticide market for plant protection; this figure can be increased in the future.     

Prevention methods for pest control and their use in Poland

Prevention methods can still be a cost‐effective and efficient tool for pest control. Rational use of prevention methods is a feasible way to reduce dependency on chemical protection in agriculture. Costs, workload and farmers' awareness are key issues, however. In Poland, crop rotation is used as a method for pest control only to a limited extent owing to the high share of cereals in the crop structure. The choice of resistant varieties is satisfactory, but farmers should make use of qualified seed material more often. Liming is recommended on the majority of farms on account of widespread soil acidity. Favourable aspects as regards the prevention of pest development are biodiversity and the popularity of prevention cultivation techniques. © 2014 Society of Chemical Industry     

A rapid method for the determination of liquid fumigant residues in food commodities using automated headspace analysis

An automated gas chromatographic headspace method capable of detecting halogenated compounds in cereals, nuts and seeds at levels down to μg kg^?1 or less has been developed and evaluated. Commodities were analysed directly without extraction or clean-up and a simple calibration technique offers a rapid screening quantitative analytical method. Comparison of results obtained using an established solvent extraction method with those obtained using the method described showed good quantitative agreement. Minimum detectable quantities were lower using the headspace method for every fumigant residue/commodity studied. The recommended analytical conditions are suitable for examination of further commodities for the fumigant residues examined and for other volatile halocarbons.     

黄色灯防治害虫的研究与应用进展

黄色灯防治害虫的原理是利用蛾类昆虫对绿黄波段(500~590nm)光敏感的特性,通过干扰蛾类害虫的日节律达到降低其种群密度的目的。本文简述了黄色灯防治技术在国内外发展及应用状况、黄色灯防治效果的影响因素,以及黄色灯在防治蛾类害虫过程中对植物生理的影响,分析了黄色灯应用中存在的问题,并且对未来黄色灯的发展和应用进行了展望。     

植物精油应用于害虫防治研究进展

从植物精油对害虫的生物活性(驱避、拒食、引诱、触杀、熏蒸、抑制生长发育)、植物精油的增效研究,以及植物精油对害虫的作用机理方面综述了植物精油用于植物保护领域防治害虫的研究进展,并展望了植物精油在植物保护中的应用前景。     

土壤熏蒸剂棉隆防治土传病害研究进展及未来发展趋势

棉隆对病原细菌、真菌、根结线虫及杂草均有较高防效,而且作为固体微颗粒剂具有使用简单、安全的特性,被广泛用于作物种植前熏蒸土壤以防治土传病虫害。施用过程中,土壤环境因素（包括土壤类型、土壤温湿度、土壤有机质及pH等）、施药方式、施药季节和施药剂量均会对棉隆的熏蒸效果产生显著影响,不正确的使用方式常会导致熏蒸效果不理想或产生药害问题。该文系统综述土壤熏蒸剂棉隆的使用概况（包括作用机制、适用作物、施用方式和施用效果等）、存在的问题及原因分析（包括施用深度、水分、温度对棉隆有效成分含量的影响及其熏蒸对土壤微生物群落结构的影响等）、解决对策（包括改善施药方式、优化土壤环境和活化熏蒸后土壤微生物等）以及未来发展趋势,以期为棉隆的高效应用提供借鉴。     

我国火龙果病虫害绿色防控技术研究进展

随着火龙果种植面积的不断扩大,火龙果病虫害问题也随之增加,极大地影响了火龙果的产量和品质。传统的化学防控技术手段已适应不了现代化农业的需求,绿色防控技术的研究与应用对火龙果的产量和品质具有重要意义。为此,本文对提高火龙果病虫害绿色防控技术中农业防控技术、物理防控技术和生物防控技术三大技术的研究与应用进展进行了综述和展望。     

Variation in the effects of take-all disease on grain yield and quality of winter cereals in field experiments

Relationships between take-all intensity and grain yield and quality were determined in field experiments on cereal crops using regression analyses, usually based on single-point disease assessments made during anthesis or grain-filling. Different amounts of take-all were achieved by different methods of applying inoculum artificially (to wheat only) or by using different cropping sequences (in wheat, triticale or barley) or sowing dates (wheat only) in crops with natural inoculum. Regressions of yield or thousand-grain weight on take-all intensity during grain filling were similar to those on accumulated disease (area under the disease progress curve) when these were compared in one of the wheat experiments. Regressions of yield on take-all intensity were more often significant in wheat than in the less susceptible crops, triticale and barley, even when a wide range of disease intensities was present in the latter crops. The regressions usually had most significance when there were plots in the severe disease category. Thousand-grain weight and hectolitre weight usually responded similarly to total grain yield. Decreased yield was often accompanied by a significant increase in the percentage of small grains. When severe take-all was present in wheat, regressions showed that nitrogen uptake was usually impaired. This was sometimes accompanied, however, by increased percentage nitrogen in the grain as a consequence of smaller grain size with decreased endosperm. Significant effects of take-all, both positive and negative, on Hagberg falling number in wheat sometimes occurred. Significant regressions of yield on take-all assessed earlier than usual, ie during booting rather than grain-filling in wheat and triticale and during anthesis/grain-filling rather than ripening in barley, had steeper slopes. This is consistent with observations that severe disease that develops early can be particularly damaging, whilst the crops, especially barley, can later express tolerance by producing additional, healthy roots. The regression parameters, including maximum potential yield (y-axis intercept) and the extrapolated maximum yield loss, also varied according to the different growing conditions, including experimental treatments and other husbandry operations. These differences must be considered when assessing the economic potential of a control measure such as fungicidal seed treatment.     

The use of entomogenous fungi for pest control and the role of toxins in pathogenesis

Fungi have been suggested as agents for the biological control of insects for over a century, but their use remains extremely limited. This paper examines the biology of entomogenous fungi, highlighting their need for moisture, and reviews studies on the Entomophthoraceae, Beauveria bassiana, Beauveria brongniartii, Metarhizium anisopliae and Verticillium lecanii. It is suggested that current studies should be directed towards the control of pests living in humid micro-climates and that moisture-retaining formulations should be developed to reduce the reliance of fungi on moisture. Many entomogenous fungi produce insecticidal toxins in submerged culture and these compounds are of interest as a source of new toxophores. The most extensively studied toxins are the cyclic depsipeptides from M. anisopliae, termed destruxins, and their possible role in pathogenesis is discussed. Beauveria bassiana also produces the cyclic peptides termed beauvericin, beauverolides, and bassianolide. Toxins produced by V. lecanii, and the Entomophthoraceae are also described.