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61.
阐述了农药对农业生产和农产品质量安全的重要性;并以目前农药市场存在的巨大隐患为前题,分析供销合作社对农药市场的规范化管理方面所承担的主渠道作用。 相似文献
62.
提出了环泵泡沫比例混合器和泡沫压力比例混合器在相应灭火系统中的应用、安装和操作中应注意的问题,对两种泡沫比例混合器组成的系统进行了对比,认为环泵比例混合泡沫灭火系统采用正压进水,可以克服负压进水方式存在的缺陷,比较适合油库火灾的扑救;压力比例混合泡沫灭火系统灵活性、匹配性较差,适用于泡沫混合液流量相对不变的火灾扑救。 相似文献
63.
冀东稻区防治主要螟虫的药剂筛选试验 总被引:2,自引:0,他引:2
2008年选择了4种杀虫剂进行防治水稻二化螟、稻纵卷叶螟的田间药剂试验,结果显示:20%康宽(CoregenTM)150 ml/hm2防效最好,其杀虫、保穗和保叶效果均超过95%,50%灵蛙1 200 ml/hm2、20%解千愁1 350 ml/hm2、15%阿维毒1 800 ml/hm2防治效果也较理想,其杀虫、保穗和保叶作用分别达90%左右。4种新型杀虫剂的防治效果显著优于常规药剂——90%杀虫单sp(900 g/hm2)、18%杀虫双(3 000 g/hm2),在试验剂量下,4种杀虫剂对水稻的正常生长无影响,安全性好。 相似文献
64.
甜菜使用甲基异柳磷拌种防治甜菜害虫,在用药量为种子量0.3%(ai)的情况下,最适用水土与种子重量之比为1:2,插后10天检测甜菜苗内含药量为最高,达0.91mg/kg;以上述用药量拌种,可在甜菜苗体内残留60天,使用不同药量拌种,对甜菜的出苗有不同的影响,并产生相应的药害,用药量与种子出苗率呈极显著的负相关(r=-0.9934),与药害则呈极显著的正相关(r=0.9938)。 相似文献
65.
66.
Consistent spray coverage that is evenly distributed throughout the canopy is necessary to control pest populations that can negatively affect yield. As applicators are switching to Coarser spray quality nozzles to reduce risk and liability of pesticide spray drift, concerns about efficacy loss are growing. Previous research has indicated that small droplets are the most effective at penetrating through crop canopies, but newer nozzle technologies have improved the effectiveness of larger droplet or Coarser sprays. Research was conducted to assess the canopy penetration of nozzles that produce Coarse, Very-Coarse and Extremely-Coarse spray qualities compared to nozzles that produce Fine and Medium spray qualities. Kromekote collectors were positioned in four configurations in an oat (Avena sativa L.) var. ‘Yarran’ (AusWest Seeds, Forbes, NSW, Australia) crop to quantify the coverage and droplet number densities (droplets cm−2) across three application carrier volume rates: 50, 75 and 100 L ha−1. Applications were made in the field in 30 cm tall, tillering oats, with collectors arranged in a randomised complete block design with three replications. The entire study was repeated on the following day. Results showed that droplet number densities were inversely related to the droplet size produced by the nozzles, yet coverage was increased more by application volume rate than droplet size. Thus, both spray drift reduction and improved canopy penetration can be achieved with proper nozzle selection and operation parameters for the control of agronomic pests. 相似文献
67.
Effects of charging voltage,application speed,target height,and orientation upon charged spray deposition on leaf abaxial and adaxial surfaces 总被引:1,自引:0,他引:1
Wastage of agricultural chemicals and ensuing environmental pollution is an issue, where ineffective spray deposition is a major concern with conventional pesticide application methods. Electrostatic spraying is known to be one of the most effective methods to improve leaf abaxial (underside) surface deposition, overall deposition, and distribution on the plant targets. Deposition of charged sprays on leaf abaxial and adaxial (upper) surfaces as influenced by the spray charging voltage (system), application speed (operational), target height and orientation (target) parameters was studied in the laboratory. An air-assisted electrostatic induction spray charging system attached to a moving carriage was used to apply charged spray at uniform application (ground) speeds. Spray deposition (101–71 μm NMD), determined using a fluorescent tracer technique increased with charging (0–5.5 mC kg−1) on leaf abaxial and decreased with charging on adaxial surface. The deposition was higher on abaxial (0.66–1.33 μg cm−2) at 30° below (horizontal plane) and on adaxial (0.78–1.79 μg cm−2) at 0° (horizontal) target orientation for lower (0.278 m s−1) application speed. At all target heights, abaxial deposition increased with charging voltage (0–4.0 kV) for medium application speed (0.417 m s−1) and adaxial deposition decreased with charging voltage for lower application speed (0.278 m s−1). The medium application speed with higher charging voltage was optimum for abaxial and adaxial deposition. The droplet velocity and charging voltage were the key factors for obtaining desired spray deposition on targets. All the selected factors including target orientation (O), application speed (S), target surface (L), and charging voltage (V), and their interactions except between O and S were significant at lower (0.35 m) and medium (0.65 m) target heights. All the factors and their interactions except between O and V were significant at higher (0.95 m) height. Electrostatically charged spray improved the underside (abaxial) and overall deposition. The deposition was substantially influenced by factors such as charging voltage, application speed, plant target height, and target orientation. 相似文献
68.
Grain legumes play an important role in community livelihood and in the national economy in Kenya. Unfortunately, in many African countries, production doesn't satisfy the demand in grains due to various constrains. Understanding farmers practices and behavior in the management of grain legume pests is a crucial step in the development of sustainable management strategies. A total of 216 farmers were surveyed in eight districts of eastern Kenya to evaluate farmers' knowledge and perceptions of grain legume pests; to examine current pest management practices, and to identify other production constraints. Grain legumes are grown by a wide age-group of farmers, with both genders equally represented. Chemical control remains the main pest management strategy, and, to ensure pesticide effectiveness, farmers also use increased application rates, chemical alternation, frequent application and mixtures of chemicals. While farmers used other control measures, they showed only limited interest in biological control. The majority of the farmers had experience in grain legume farming and were able to identify the major pests, which were the legume flower thrips Megalurothrips sjostedti Trybom, the cowpea aphid Aphis craccivora Koch and the legume pod borer Maruca vitrata Fabricius. Our survey revealed that education and proximity to extension services contributed significantly to farmers' knowledge of grain legume pests, suggesting the need to provide continuous training and capacity building on integrated pest management in grain legume farming. The study also suggests integration of other pest management strategies such as the use of early maturing varieties, biopesticides and biofertilizer to reduce the use of chemical for sustainable pest management. 相似文献
69.
Conservation value of the herbaceous vegetation in hedgerows - does organic farming make a difference? 总被引:1,自引:0,他引:1
The aim was to compare and test differences in the conservation value of hedge bottom vegetation on organic and conventional farms. The studied hedgerows (28 organic and 28 conventional) were on average 14 years old and established in the same way, except that organic hedgerows were established and managed without use of pesticides. We investigated three sample plots of 10 m2 in all hedgerows together with a set of 13 explanatory variables. There were no differences in soil texture between hedgerow types but organic farms had higher pH and lower conductivity. Organic farms had higher total N values, which are explained by a slightly higher content of organic matter. There was highly significant interaction between farming type and neighbouring crop type according to soil phosphate concentration. Significantly more plant species were found in the organic hedgerows. The species compositions in organic hedgerows appeared significantly more similar to semi-natural communities when compared with other plant communities. We conclude that organic farming is slightly superior with regard to conservation of herbaceous diversity of hedgerows in intensively cultivated agricultural landscapes. The possible reasons for this are discussed. 相似文献
70.
Zewei?Miao Laura?Padovani Carlo?Riparbelli Amy?M.?Ritter Marco?Trevisan Ettore?CapriEmail author 《Paddy and Water Environment》2003,1(3):121-132
Pesticides are very important in European rice production. For appropriate environmental protection, it is useful to predict the potential impact of pesticides after application, in paddy fields, in paddy runoff, and in the surrounding water, by calculating predicted environmental concentrations (PECs). In this paper, a joint simulation is described, coupling a field-scale pesticide fate model (RICEWQ) and a transportation model (RIVWQ) to evaluate the potential for predicting environmental concentrations of pesticides in the paddy field and adjacent surface water bodies and comparing the predicted values with the monitoring data. The results demonstrate that the application of the calibrated field-scale RICEWQ model is a conservative method to predict the PEC at the watershed level, overestimating the observed data; the coupled RICEWQ and RIVWQ models could be adequately used to predict PECs in the surrounding water at watershed level and in the higher tier risk assessment procedure. 相似文献