Weed control in conservation agriculture systems of Zimbabwe: Identifying economical best strategies     

《Crop Protection》2013

Weed management under conservation agriculture (CA), especially when manually controlled is one of the major setbacks for the widespread adoption of CA in southern Africa. This study was conducted at three on-station and three on-farm sites: CIMMYT-Harare, Domboshawa Training Centre and Henderson Research Station (on-station sites), Hereford farm, Madziva communal area and Shamva communal area (on-farm sites). The evaluation focused on the effect of initial herbicide application and succeeding manual weeding whenever weeds were 10 cm tall or 10 cm in length for grasses with stoloniferous–rhizomatous growth habit. Weeds counts, weeding time and grain yields were collected at all on-station sites. At the on-farm sites, weed counts were done before weeding and a number of farmers were timed during weeding. The results showed that herbicides use reduced the weed density and time taken on weeding at all sites. Combining herbicides e.g. atrazine, glyphosate and metalachlor had the lowest weed density and weeding time at all sites. However, the treatments had no effect on maize grain yields suggesting that appropriate and timely manual weeding reduced crop/weed competition. Herbicides treatments had higher input costs than manual weeding due to the additional cost of herbicide but the treatment with manual weeding only had more overall labour days compared to the mixture of three herbicides. In order to achieve economic benefits, smallholder farmers may use the time for value addition e.g. expand cropped land area, use time for value addition, or sell new products on the market. Herbicides use reduces the manual labour needed to control weeds and minimise total crop failure due to untimely weeding hence, herbicides are an important but not the only weed control option under CA systems in Zimbabwe.  相似文献   

Effect of pre-emergence herbicide mixtures on cowpea (Vigna unguiculata (L.) Walp) at Samaru, in northern Nigeria     

D.B. Ishaya  P. Tunku  M.S. Yahaya 《Crop Protection》2008,27(7):1105-1109

Field experiments were conducted in the wet seasons of 2005 and 2006 to evaluate the effect of pre-emergence application of herbicides on cowpea. A mixture of metolachlor and prometryn at 1.25+0.08 kg a.i./ha was consistent in better growth and seed yield. However, application of mixtures of metolachlor and terbutryn at 0.99+0.50 kg a.i./ha and ametryn and terbutryn at 1.60+1.00 kg a.i./ha gave lower vigour score of the crop, higher crop injury, smaller canopy spread and lower seed yield. It can be concluded that the metolachlor and prometryn mixture gave good selective weed control and can be used instead of hand weeding in cowpea in northern Nigeria.  相似文献   

Weed control and sesame (Sesamum indicum L.) response to preplant incorporated herbicides and method of incorporation     

W. James Grichar  Peter A. Dotray 《Crop Protection》2007,26(12):1826-1830

Field studies were conducted at two sesame-growing regions of Texas in 2004 and 2005 to determine weed control and sesame response to four dinitroaniline herbicides and their method of incorporation. Ethalfluralin, pendimethalin (formulated as Prowl EC), and trifluralin were applied at the X, 1X, and 2X of the suggested label dose for Gossypium hirsutum L. Pendimethalin (formulated as Prowl H₂O) was applied at the X, 1X, and 1X rate. Two methods of incorporation included rolling cultivator mixing wheels and spring tooth harrow. With rolling cultivator mixing wheels, all herbicides controlled Amaranthus tuberculatus (Moq.) J.D. Sauer at least 74% regardless of dose. The X dose of ethalfluralin and pendimethalin (formulated as Prowl EC), or the X and 1X dose of pendimethalin (formulated as Prowl H₂O) controlled Brachiaria platyphylla (Griseb.) Nash no better than 73% while all other doses of the herbicides controlled B. platyphylla at least 80%. The use of mixing wheels to incorporate the herbicides resulted in better sesame stands and less stunting than the use of the spring tooth harrow; however, sesame stands were reduced as herbicide rate increased when using mixing wheels. Ethalfluralin at the 1X dose, pendimethalin (formulated as Prowl H₂O) at the X dose, and trifluralin at the X dose produced the highest sesame yield while ethalfluralin at the 2X dose produced the lowest yield.  相似文献   

不同除草剂与杀菌剂混用对小麦的安全性试验     

李培玲  冯文涛  宋梁栋 《陕西农业科学》2021,(6):79-81

为明确当地冬小麦田常用除草剂和杀菌剂混用的药效及对小麦的安全性,探索一次施药兼防兼治病虫杂草的目的, 通过设置7个除草剂与杀菌剂的混合使用,记载各处理对小麦有无药害,药害症状和程度;同时观察对小麦条锈病防治效果。结果表明,药剂混配使用有增效和扩大防治对象的作用,节省劳动力,但二甲唑草酮·双氟磺草胺和甲基二磺隆二者之间不能混配使用。  相似文献   

稻田除草剂对田埂显花植物的影响     

常向前  吕亮  余思策  张舒 《安徽农业科学》2014,42(36):13066-13069

[目的]了解稻田除草剂对田埂显花植物的影响,为稻田除草剂的应用提供参考。[方法]研究了稻田4种常用除草剂(五氟磺草胺、氰氟草酯、苄嘧磺隆、二氯喹啉酸)对田埂显花植物芝麻、大豆的影响。[结果]4种除草剂不论是土壤处理还是茎叶处理,均以二氯喹啉酸对芝麻的影响最大,对芝麻的生长抑制率均为0.834~1.000;土壤处理中,二氯喹啉酸对大豆的影响最大,生长抑制率为0.991~0.994,茎叶处理中,氰氟草酯对大豆的影响最大,生长抑制率为0.477~0.534。[结论]该研究结果为除草剂的安全性使用及稻田病虫害的综合防治提供了理论依据。  相似文献   

几种韭菜田除草剂大田防除效果及其安全性研究     

郭振营李梦姣  王振军 《安徽农业科学》2014,(25):8605-8607

[目的]筛选效果较好的韭菜田除草剂。[方法]通过大田试验研究了5种韭菜田除草剂的防效并评价了其对韭菜的安全性。[结果]对于单子叶杂草的防治效果,10%精喹禾灵EC+特殊助剂的综合防治效果最好,330 g/L二甲戊灵EC、200 g/L氯氟吡氧乙酸EC、10%乙羧氟草醚EC、56%2甲4氯钠SP较差;对于双子叶植物,除330 g/L二甲戊灵EC外,10%精喹禾灵EC+特殊助剂、200 g/L氯氟吡氧乙酸EC、10%乙羧氟草醚EC、56%2甲4氯钠SP都有较理想的防效,防治效果都可达90%以上。330 g/L二甲戊灵EC对韭菜田整个生长过程没有明显药害产生,其他药剂在使用初期不同程度地产生药害,尤其10%乙羧氟草醚EC产生触杀性药害,造成负的增产率,但药害程度会随韭菜的生长不断减轻。[结论]推荐使用10%精喹禾灵EC+特殊助剂防治韭菜田杂草。  相似文献   

高锰酸钾与粉末活性炭去除水中3,4-二氯三氟甲苯的研究     

杨智临  张鲁宁  陈海  张忠磊  杨琦 《安徽农业科学》2014,(34):12107-12110

利用高锰酸钾与粉末活性炭去除水中农药中间体3,4-二氯三氟甲苯（3,4-DCBTE）,并对反应影响因素进行了研究.结果表明,单独使用高锰酸钾的最佳反应条件为高锰酸钾0.5 mg/L、pH 3、温度30℃;单独使用粉末活性炭的最佳投加量为0.3 g/L;两者联用在高锰酸钾浓度为0.5 mg/L、粉末活性炭浓度为0.1 g/L时,5 min内可完全去除3,4-DCBTE.  相似文献   

宁夏地区羊草除草剂研究     

解艳玲  王奇  马文礼  杨刚  李宗泽 《宁夏农林科技》2014,(10):29-30

羊草苗期易受到杂草侵害,妨碍其生长。2012—2013年进行了一年生和两年生羊草除草剂的试验研究,结果表明:在一年生羊草的芽前封闭试验中,苄嘧·唑草酮、湖北地质大学除草剂处理1 m行长内有羊草61株、杂草28株,适合大田使用;咽嘧·莠去津1 m行长内有羊草23株,杂草195株,效果次于苄嘧·唑草酮和湖北地质大学除草剂。对两年生羊草来说,禾本科杂草,苄嘧·唑草酮360 g/hm2除草效果较好,且药效适当,湖北地质大学除草剂药效次之;对于阔叶杂草,2,4-D丁酯750 m L/hm2、烟嘧磺隆1 500 m L/hm2除草效果较好,且对两年生羊草危害较小,只有3%的羊草基部叶片变红。  相似文献   

除草剂混合标准溶液中标准物质稳定性研究   总被引：1，自引：0，他引：1  

梁旭锋  王岩  林黎明  孟祥红  李玉翠  陈楠 《山东农业科学》2014,(4):106-109

选取德国DR公司生产的28种除草剂标准物质,将其配制成混合标准溶液后转移至20 mL带聚四氟乙烯衬盖的棕色螺口样品瓶中,于-18℃避光贮存,采用液相色谱串联质谱法测试各组分量值随贮存时间的变化。结果表明:在90天内,标准物质各组分量值的标准偏差在12~73μg/L范围内,最大相对标准偏差为3.04%(n=5),测量结果的相对不确定度小于5.60%。在置信度为95%时,标准物质各组分量值在(1 000±113)μg/L范围内,测量的偏差不显著。在不超过标准物质的有效期内,稀释混合分装后的标准物质可保存90天。  相似文献   

除草剂污染堆肥用量对黄瓜生物有效性的影响     

王智中  吕潇  杜龙龙  李彦明  Fredrick C. Michel Jr. 《中国蔬菜》2013,1(18):67

化学除草已成为确保现代农业生产不可或缺的技术，但因除草剂会在非靶标植物中残留，进
而导致堆肥和有机肥料产品被除草剂污染，为避免堆肥及其产品在不合理应用时对后茬植物的生长产生不
良影响，造成不可挽回的损失，本试验采用市售基质、普通堆肥和受除草剂污染的堆肥为试材，设置无污
染堆肥处理（C1）、氯氨吡啶酸污染堆肥处理（C2）和二氯吡啶酸污染堆肥处理（C3）3 个处理，在0、5%、
10% 和20% 堆肥不同用量条件下，以黄瓜的出苗率和播种后45 d 时植株的节间距、株高、茎粗、植株干质量、
叶片数、叶面积、叶片卷曲情况和壮苗指数为评价指标。结果表明，受除草剂污染的堆肥对黄瓜种子的萌
发有抑制作用，且堆肥用量越大，出苗率越低，而且黄瓜幼苗表现出严重的除草剂药害症状，植株纤弱，
叶片狭小、卷曲。两种除草剂污染堆肥对黄瓜的影响呈现不同的规律，在堆肥用量相同的条件下，氯氨吡
啶酸比二氯吡啶酸对黄瓜的药害严重，这表明越高效的除草剂随堆肥或有机肥的施用对后茬敏感植物的药
害风险越大。  相似文献