Evaluation of foramsulfuron-sodium + thiecarbazone-methyl + cyprosulfamide for post-emergence weed control in cassava (Bayer_2020)

Monsoon Active [foramsulfuron-sodium + thiecarbazone-methyl + cyprosulfamide ] was evaluated for post-emergence weed control cassava and cassava/maize intercrop for three years at six different sites across five States [Benue, Ogun, Osun, Oyo, and the Rivers States] in Nigeria. Monsoon was compared with Paraquat, a toxic herbicide already marked for de-registration in Nigeria. The evaluation included manual hoe weeding treatments. All post-emergence herbicides treatments in the assessment were applied under the canopy with a backpack spray fitted with a sprayhood. In 2020, a treatment where Monsoon was used under cassava canopy without a sprayhood was included in the assessment. All the trials were set up in a randomized complete block design and replicated four times. Cassava was monitored for injury. Treatment efficacy was assessed visually and from weed dry matter. Cassava and maize population at crop harvest and yield were assessed. The result showed that Monsoon was superior to Paraquat and manual hoe weeding in reducing weed pressure at most sites. Monsoon provided excellent control of major cassava weeds at all the sites. Monsoon did not affect crop stand negatively or depress cassava yield in both monocrop and intercropped plots. No crop injury was observed when Monsoon was applied under cassava canopy with or without a sprayhood at 7 to 8 weeks after planting cassava, indicating that Monsoon is suitable for post-emergence weed control in cassava and a potential replacement for Paraquat.

本研究针对复配除草剂Monsoon（有效成分：甲酰磺草隆钠<foramsulfuron-sodium>、噻酮磺隆甲酯<thiecarbazone-methyl>、解草啶<cyprosulfamide>）开展了为期三年的苗后杂草防控效果评价，试验在尼日利亚5个州（贝努埃州、奥贡州、奥孙州、奥约州及河流州）的6个不同试验点进行，涵盖单作木薯与木薯/玉米间作两种种植模式。试验将Monsoon与已在尼日利亚被列入撤销登记名录的高毒除草剂百草枯（Paraquat）进行对比，同时设置人工锄草处理组。所有苗后除草剂施药均采用加装喷雾防护罩的背负式喷雾器，在作物冠层下方施药。2020年新增了「木薯冠层下无喷雾防护罩施用Monsoon」的处理组。所有试验均采用随机完全区组设计（randomized complete block design），设置4次重复。试验期间定期监测木薯的药害发生情况，通过目视评估与杂草干物质重测定两种方式评价药剂防控效果；在作物收获期，分别调查木薯与玉米的种群密度及籽粒产量。试验结果表明，在绝大多数试验点中，Monsoon在降低杂草发生危害程度方面均优于百草枯与人工锄草处理；在所有试验点中，Monsoon均可对木薯田主要杂草实现优异防控效果。无论是单作还是间作模式下，Monsoon均未对作物立苗产生负面影响，亦未降低木薯产量。在木薯种植后7~8周施药时，无论是否加装喷雾防护罩，均未观察到木薯出现药害症状，这表明Monsoon适用于木薯田苗后杂草防控，具备作为百草枯替代药剂的潜力。