共查询到19条相似文献,搜索用时 360 毫秒
1.
2.
3.
4.
生物农药是指从动、植物体内提取的各种防病、杀虫、除草的活性物质和微生物及其代谢产物来防治病虫害和调节植物生长,它包括植物源农药、动物源农药和微生物源农药三大类. 相似文献
5.
6.
7.
8.
9.
10.
11.
12.
T. Sibanda H. M. Dobson J. F. Cooper W. Manyangarirwa W. Chiimba 《Crop Protection》2000,19(8-10):807-815
Smallholder vegetable production is expanding rapidly in Zimbabwe both for local sale in urban markets and for export. Pest management practices of 12 small-scale vegetable farmers in two areas of Zimbabwe were surveyed over a five-month period to gather information on crops, pests, diseases and crop protection methods. A range of serious pests and diseases affects non-indigenous vegetables such as Brassicas, tomatoes, onions and cucurbits. Although farmers use some cultural control methods and occasionally botanical pesticides, pest control is predominantly by the use of conventional synthetic pesticides. These are usually applied through lever operated knapsack sprayers although some less orthodox application methods are occasionally used. Results are variable and there are concerns about risks to sprayer operators, consumers and the environment (including natural enemies) due to shortcomings in protective clothing, large deviations from recommended doses and excessive run-off to the soil. Field trials were carried out to evaluate a modified sprayer lance which directs the spray upwards rather than downwards in an attempt to place more of the spray under the leaves where most of the arthropod pests are found. The ‘V lance’ as it is called improved the uniformity of spray coverage on the upper and lower leaf surfaces and is expected to improve efficacy of spraying and/or offer the opportunity to reduce doses or spray frequencies. Farmers who tested the device reported good results and gave constructive feedback for future improvements. The smallholder vegetable sector requires support in the form of improved access to existing pest management information (in an appropriate form) and focused research targeted at the knowledge gaps which currently impede implementation of sustainable IPM. 相似文献
13.
近年来,我国部分茶区茶网蝽暴发成灾,缺乏高效安全防治技术。以低水溶性化学农药、植物源农药为对象,从施药方法、药剂种类、药剂浓度、农药残留等方面,研究了茶网蝽药剂防治技术。结果表明,背负式机动弥雾机施药的防效显著高于背负式电动喷雾器,且防效随施药用水量增加显著提高。8种低水溶性化学农药单剂中,联苯菊酯、高效氯氰菊酯、甲氰菊酯对茶网蝽具有很好的防效,其有效成分用量分别在1.31、22.50、11.25 g·hm-2时,施药后7 d防效可达90%以上,且干茶中的农药残留量均低于中国、欧盟等规定的最大残留限量标准;唑虫酰胺效果次之,施药后7 d防效为60%~70%;而虫螨腈、乙基多杀菌素、茚虫威、噻嗪酮等低水溶性农药的防治效果均不理想。3种复配化学农药中,高氯·吡丙醚效果最好,施药后7 d防效可达89%。3组植物源农药中,除虫菊素效果最好,其有效成分用量在45.00 g·hm-2时,施药后7 d防效可达90%;印楝素与藜芦碱混配、印楝素与苦参碱混配,对茶网蝽的防治效果均不理想。综上所述,通过背负式机动弥雾机施用拟除虫菊酯类化学农药和除虫菊素,是一种高效安全防治茶网蝽的方法。 相似文献
14.
Vázquez-de-Aldana García-Ciudad Pérez-Corona & García-Criado 《Grass and Forage Science》2000,55(3):209-220
From 1987 to 1996, the nutritional quality of the main botanical components (grasses, legumes and forbs) in semi-arid grasslands in the dehesa ecosystem in western Spain was analysed. Herbage samples were collected at the end of spring, in 30 locations, at two different topographic positions (upper and lower slope zones). Herbage mass over 2 cm and proportion of botanical components were estimated and samples were analysed for crude protein, neutral-detergent fibre (NDF), hemicellulose, cellulose, lignin and in vitro dry matter digestibility (DMD). Analysis of variance revealed a significant effect of sampling year on the herbage mass, proportion of botanical components and their nutritional quality. The three botanical groups, grasses, legumes and forbs, followed similar year-to-year trends in their crude protein, cellulose and lignin contents and in vitro DMD. Herbage mass was not significantly related to any meteorological variables, suggesting that interannual variation in biomass production of botanically complex pastures cannot be explained by a single factor. However, annual precipitation was significantly related to the proportion of the botanical group that was dominant at each slope zone: grasses in the lower zone and forbs in the upper zone. In the upper zone, spring precipitation explained part of the interannual variation in the NDF, cellulose, lignin contents and in vitro DMD of the botanical components. 相似文献
15.
为了筛选出植物源杀菌剂防治水稻稻瘟病的最佳用药剂量,2011年做了药效对比试验。结果表明,植物源杀菌剂处理30 ml/667 m2药剂量防治效果最好,但其防治效果仍低于富士一号处理。 相似文献
16.
化学杀虫剂对弱筋小麦籽粒安全性和品质的影响 总被引:1,自引:1,他引:0
为了探索弱筋小麦优质、高效、安全生产的杀虫剂使用方法,以扬麦13为材料,采用二因素随机区组设计,评价了三种化学杀虫剂在不同时期喷施对籽粒安全性和品质的影响。结果表明,三种化学杀虫剂在不同时期施用,均对小麦生长安全,不影响小麦的食用安全性。喷施化学杀虫剂后,显著降低籽粒蛋白质含量,显著提高淀粉含量,极显著提高蛋白质产量、淀粉产量和千粒重,RVA粘度特性大多数参数值上升,出粉率和弱化度显著提高,形成时间、稳定时间、评价值降低,而对拉伸仪参数无显著影响;吡虫啉和氧化乐果对品质改善的作用略大于毒死蜱。在抽穗开花期至花后7 d喷施,可获得较高的千粒重、蛋白质产量和淀粉产量,同时蛋白质含量较低,淀粉含量较高,粉质参数中形成时间、稳定时间较低,弱化度较高,更有利于弱筋小麦品质的形成;喷施时期对扬麦13直链淀粉含量、总淀粉含量和RVA粘度特性参数、拉伸仪参数的影响较小,均未达到显著水平。药剂和喷施时期之间互作不显著。 相似文献
17.
寻找和开发安全有效的植物性杀虫剂,以丰富植物源农药的来源,填补化学农药禁限用留下的空白。甲醇冷浸提取法制备辽细辛、石楠藤、金狮藤等16种中草药的提取物,采用无限量取食法,测定了对家蝇成虫的活性,采用幼虫浸液法,测定了对埃及伊蚊四龄幼虫的活性。结果表明:在10mg/mL浓度下,处理家蝇48h后,辽细辛、石楠藤、金狮藤、单叶细辛校正死亡率分别为100%、100%、100%和98.33%,LC50值分别为0.1483、0.1544、3.5277和2.4292mg/mL,三叶鱼藤LC50值为0.9080 mg/mL;在0.5 mg/mL浓度下处理埃及伊蚊四龄幼虫48 h,辽细辛、石楠藤、金狮藤、单叶细辛、厚朴校正死亡率分别为100%、100%、100%、100%和100%,LC50值分别为0.0046、0.0094、0.0570、0.0658和0.0504 mg/mL,三叶鱼藤为0.1194 mg/mL。辽细辛、石楠藤、单叶细辛、金狮藤对两种试虫均表现出优良的杀虫活性,均优于或接近三叶鱼藤活性。 相似文献
18.
花生种质资源的综合评价 总被引:16,自引:4,他引:12
对5700份花生种质资源的植物学性状和经济性状、抗病性和种子品质性状进行了鉴定评价,筛选出高抗锈病种质92份,高抗早斑病种质77份,高抗晚斑病种质53份,高抗根结线虫资源3份,高抗青枯病资源102份,抗锈病兼抗早斑病资源58份,抗锈病兼抗晚斑病资源49份,抗锈病兼抗早、晚斑病资源45份,抗青枯病兼抗根结线虫资源2份,抗青枯病兼抗锈病资源1份。蛋白质含量达34%以上的33份,含油量达58%以上的24份,油酸含量达67%以上的18份,亚油酸含量达47%以上的15份。不同类型不同来源的花生品种的植物学性状、经济性状、抗病性和种子品质性状均有显著差异。 相似文献
19.
2015~2018年对东北中西部春玉米区玉米病虫草害防治用药情况进行调查。结果表明,该区域玉米田化学农药的使用量占农药总使用量的99%以上。吉林省玉米田农药年均用量为3 216.45 g a.i./hm~2,内蒙玉米田化学农药年均用量为1 133.44 g a.i./hm~2。各类化学农药按照使用量排序依次为除草剂杀虫剂杀菌剂,除草剂使用量占农药总用量的75%以上。苗后除草剂用量显著低于苗前除草剂用量,选择苗后除草的农户比例和应用面积逐年增加,各类苗后除草剂存在不同程度的超量应用现象。提出通过以草优化配方,减少长残留除草剂用量、明确苗后施药关键时期、升级施药器械、开展技术培训等措施、结合病虫害绿色防控技术,集成农药减施综合技术模式。 相似文献