共查询到20条相似文献，搜索用时 500 毫秒
1.
2.
3.
近年来，随着种植业结构的调整，棉田间套种蔬菜面积逐步扩大，提高了土地利用率和单位面积经济效益，但化工产品在农田的投入也日趋增多，农产品的污染问题愈加突出，特别是残留在蔬菜上的高毒农药，酿成的中毒事故屡有发生。同时，由于经济的发展，生活水平的提高，人们的消费观念也在逐渐改变，对“绿色食品”、“有机食品”的需求量逐年增加。为解决棉田套种蔬菜质量与产量的矛盾，我们对棉田间套种蔬菜农药污染及其治理进行了初步探讨。１ 农药污染原因１．１ 直接污染——防治蔬菜病虫使用农药。棉田间套种蔬菜病害发生种类较多，西… 相似文献
4.
新疆棉田农药药害类型及补救措施 总被引：1，自引：0，他引：1
近年来,在新疆地区棉花生产中,使用除草剂、生长调节剂、杀虫剂等农药已成为棉花高产栽培必不可少的技术措施.但在棉田使用农药过程中,由于农药品种选择错误、使用浓度过大、使用方法不当等原因常造成棉花药害,导致品质下降、减产甚至绝收.根据多年对棉田各种农药药害情况的观察,结合生产实践,现提出对棉田农药药害进行以下四种综合分类: 相似文献
5.
棉田多次施用农药后,对棉花产量的效应涉及到农药的经济效益。对此,各地反映颇多,众说不一。为了研究不同类型的农药在棉田上多次施用后对棉花产量的效应以及治虫的效果如何?我们于1982年组织7个县11个单位进行试验。今将各类农药对棉红 相似文献
6.
7.
长期以来棉田使用农药的品种单一、过于集中 ,造成棉田害虫抗性增强 ,并有可能出现导致部分害虫大发生的灾害现象 ,还造成使用中人体中毒和使用后环境中毒。1棉田使用化学杀虫剂的现状及后果棉田主要害虫有 :地老虎、棉蚜、棉蓟马、盲蝽象、玉米螟、红铃虫、红蜘蛛、棉铃虫、斜纹夜蛾、造桥虫等。棉花从播种到收获 ( 2 0 0多天 )都受到害虫危害。因而在棉田使用化学杀虫剂时间长、次数多、用量大 ,用药种类目前还过于集中。使用的农药品种主要有 :有机磷类、拟除虫菊酯类及其混剂等。近几年我国由于采用以化学防治为主的综合防治 ,每年挽回… 相似文献
8.
棉田化学除草剂的应用王延琴，潘学标中国农科院棉花所安阳４５５１１２１国外对除草剂的应用国外采用化学除草的历史较早。６０年代，化学除草得到迅速发展。１９６０年除草剂的销售额为１．７亿美元，仅占世界农药销售总额的２０％，至１９７０年上升到３４．８％；８０... 相似文献
9.
针对2008年因棉铃虫大暴发造成植棉成本投入增加的现象,2009年新疆兵团农八师八十三团及时调整了棉花种植品种。该团的6666.7hm2棉田全部推广种植了“冀棉958、标杂A1”等抗虫棉品种,与2008年相比,每公顷仅农药费用就减少了900元,为全团职工省下了400万元的农药支出。同时,该团还推广了高衣分的棉花新品种,98%的棉田运用了新产品,推广种植了1466.7hm2的超宽膜棉田,节水灌溉面积占棉花播种面积的90%以上。 相似文献
10.
农药防治棉花害虫注意的问题王安源新疆巴楚兵团农三师五十二团农技站３４３８０６正确使用农药防治棉花害虫是确保棉花丰产丰收的重要手段，但农药也能杀伤天敌，破坏棉田生态平衡，致使害虫加重危害。因此，重于调查益害虫情动态，改进防治措施，合理制定防治指标，发挥... 相似文献
11.
Textile fibers were obtained from secondary polyethylene terephtalate (PET) and its mixtures with primary PET at initial orientation of 18000–33000 %, rate of additional orientation drawing 3.5–6.5 times and temperature of thermal fixation 363–413 K. The fibers’ tensile strength was found to decrease and elongation at break to increase with the decrease of their linear density under the conditions of fibers formation. For the fibers based on polymer mixtures, the presence of oxidized fragments in the secondary PET limited the compatibility of the two polymers which resulted in deteriorated tensile properties. The linear density (4–16 dtex), tensile strength (30–50 cN/tex) and elongation at break (20–60 %) of the PET fibers obtained were close to these for the industrially produced polymer fibers. The values of the average diameter of the fibers formed and oriented under laboratory conditions allows classifying them between the fine and the coarse textile fibers which makes them suitable for the textile industry. 相似文献
12.
Gas-exchange characteristics of potato (Solanum tuberosum L.) canopies were determined with crop enclosures under condition of optimal water supply, during soil water depletion, and during recovery from drought-stress. The plants were grown under a rainshelter in large containers with 2-m2 surface area. Control plants received water throughout the growth period. In Expt. 1, transient drought was imposed by interrupting water supply completely for 22 days. During the 33-day period of drought treatment in Expt. 2, the stressed plants received half the amount of water that was given to the control plants (irrigations 2–3 times per week).
During soil water depletion, stomatal conductance of the canopy was reduced earlier and more than photosynthesis. This resulted in a lower internal carbon dioxide concentration in the leaves of stressed plants and a higher ratio between photosynthesis and stomatal conductance. The value of that ratio increased as soil water potential dropped.
Water-use efficiency ( ) increased during drought stress. The cultivar Bintje showed a larger ratio between photosynthesis and stomatal conductance of the canopy and a higher than cv. Saturna, both for optimal water supply and during drought stress.
Photosynthesis and conductance of the canopy started to recover immediately upon rewatering, even when relative values had declined to 20–30% during the preceding stress period. After release from stress, the leaves in the top layer of the canopy had a higher stomatal conductance in treated plants than in control plants. 相似文献
13.
14.
2017—2018年,在同安镇粮食产能区示范推广水稻病虫害绿色防控与统防统治融合技术模式,取得了显著成效。融合技术示范区比常规区减少用药2~3次,用药量减少37.6%,防治成本降低400元/hm^2;水稻产量增加12.8%,收益增加2 835元/hm^2。 相似文献
15.
《Journal of Crop Improvement》2013,27(1):313-324
Summary Arbuscular mycorrhizae were inoculated into phosphorus-deficient soil fertilized with either organic or chemical fertilizer with cucumber (Cucumis sativus L.) as the first crop and lettuce (Lactu-ca sativa L.) as the second crop but without additional fertilization and AM inoculation. AM increased dry matter and fruit yield of cucumber significantly in the unfertilized, organic-fertilized and P-deficient plants compared with the fully chemical-fertilized plants. AM inoculation increased the available phosphorus in plant and soil by around 30% for all treatments except for those chemically-fertilized. The rate of AM infection did not differ significantly among the fertilization treatments, but the infection intensity was higher in unfertilized, organic-fertilized and phosphorus-deficient treatments than chemical-fertilized treatment. The residual effects of AM-inoculated to cucumber were evident for lettuce in all pre-treatments that were unfertilized and un-inoculated for the second cropping. Without P-fertilization, neither crop could grow optimally even when the soil was inoculated with AM, suggesting that AM could not serve as a substitute for phosphorus fertilizer. However, the other beneficial effects of AM on crop growth and yield could not be fulfilled with phosphorus fertilizer. 相似文献
16.
17.
18.
生物质能作物——甘薯开发利用现状及趋势 总被引：13，自引：0，他引：13
甘薯是世界上重要的粮食、饲料、工业原料及新型能源用块根作物，在我国乃至世界再生能源开发中起到重大作用，其分布地域广，适应性强，沙荒地、岗坡地均可种植。生物产量高，而且种植栽培容易。甘薯含淀粉15％～30％，晒干率20％～35％，世界各国以薯干或淀粉为原料生产乙醇有着悠久的历史。随着全球能源的日趋紧张，乙醇作为一种可再生的环保燃料．将快速步入全球成品油市场，在替代汽油供应方面起到越来越大的作用。各国正在推行或制定燃料乙醇计划，并着眼于生物燃料乙醇应用方案，认为甘薯可能是摆脱将来粮食和能源危机的“最后一张王牌”。 相似文献
19.
百香果是海南省的新兴产业,也是我国多个省区扶贫攻坚的重要产业。病虫害是影响百香果产业的重要因素,随着海南百香果种植面积越来越大,病虫害对百香果产业的不利影响越来越凸显。由于缺乏百香果病虫害种类调查鉴定的基础性研究,许多种植户对田间发生的病虫害种类识别不足,从而影响了百香果病虫害的防控效果。为了摸清海南百香果种植区的病虫害种类,于2019—2021年对海南省儋州市、乐东县、屯昌县、文昌市、三亚市、东方市、保亭县、白沙县、海口市等百香果种植区的病虫害进行了系统调查与鉴定,并对其发生危害特点进行了研究。鉴定发现海南百香果种植区的病害有11种,分别是病毒病、茎基腐病、炭疽病、疮痂病、疫病、灰霉病、果腐病、褐斑病、烟煤病、藻斑病和缺镁。重要病害为病毒病和茎基腐病,危害程度分别为4级和3级,炭疽病和疮痂病危害也较重,危害程度均为2级,其他病害危害较轻。害虫有28种,分别是黄胸蓟马、茶黄蓟马、红带蓟马、美洲棘蓟马、普通大蓟马、咖啡木蠹蛾、美洲斑潜蝇、橘小实蝇、斜纹夜蛾、双线盗毒蛾、绿丽刺蛾、白带锯蛱蝶、烟粉虱、温室白粉虱、柑橘粉蚧、木槿曼粉蚧、藤壶蜡蚧、茶角盲蝽、樟颈曼盲蝽、稻绿蝽、中稻缘蝽、茶小绿叶蝉、丽球瓢蜡蝉、绿鳞象甲、眼斑芫菁、白条豆芫菁、甘薯梳龟甲和朱砂叶螨。重要害虫为黄胸蓟马和咖啡木蠹蛾,危害程度均为3级,茶黄蓟马和美洲斑潜蝇的危害也较重,危害程度均为2级,其他害虫危害较轻。软体动物3种,分别是灰巴蜗牛、同型巴蜗牛和一种尚未鉴定的蛞蝓。本研究明确了海南百香果种植区病虫害具体种类,新发现百香果病害1种和害虫24种,为海南百香果病虫害的精准防控提供技术支撑。 相似文献