10%异噁草松·异丙甲草胺·扑草净颗粒剂防除莲藕田杂草田间药效试验

Field Efficacy Test of Clomazone-Metolachlor-Prometryne 10% GR Formulation in Controlling Weeds in Lotus Root Fields

为明确10%异噁草松·异丙甲草胺·扑草净颗粒剂防除莲藕田杂草的效果、使用剂量以及莲藕安全性,为大面积推广应用提供科学依据。试验以鄂莲5号为供试莲品种,设9个处理,4次重复,采用随机区组设计,在莲藕立叶高出水面20～30cm时撒施。结果发现,10%异噁草松·异丙甲草胺·扑草净颗粒剂可有效防除浮萍(Lemna minor)、水绵(Spirogyra sp.)、双穗雀稗(Paspalum distichum L.)、水苋菜(Ammannia baccifera L.)和丁香蓼(Ludwigia prostrata)等杂草,用药量分别为450～1 080 g/hm2。药后45 d对水绵、浮萍的覆盖度防效,双穗雀稗、水苋菜和丁香蓼综合鲜质量防效为84. 90%～98. 74%,显著高于对照药剂480 g/L异噁草松乳油189 g/hm2、72%异丙甲草胺乳油110 g/hm2和40%扑草净可湿性粉剂500 g/hm2。药后15 d目测观察,10%异噁草松·异丙甲草胺·扑草净颗粒剂各浓度处理区莲藕浮水叶片枯斑数量明显高于空白对照,但立叶高出水面莲藕叶片茎杆生长正常,无褪绿、畸形、扭曲等药害症状。根据测产结果 10%异噁草松·异丙甲草胺·扑草净颗粒剂4个剂量处理区莲藕产量较空白对照区增加20%左右。其中,630 g/hm2处理小区增产较空白对照区增产36. 51%,与人工除草没有显著差异。10%异噁草松·异丙甲草胺·扑草净颗粒剂在莲藕立叶高出水面20～30 cm时撒施除草效果显著,其经济有效用量为630 g/hm2。

A field experiment was conducted by using E-lian 5 as the tested lotus roots variety,with 9 treatments and 4 replicationsin a randomized block design. Clomazone-metolachlor-prometryne 10% GR was applied when the lotus leaves were above the water level for 20~30 cm to determine its efficacy on weeds infesting the lotus-root fields,its selectivity to lotus roots,and its use dosage, as the basis for its possible application at large scale. At 450~ 1 080 g/hm^2 the formulated herbicide mixture effectively controlled Lemna minor,Spirogyra sp., Paspalum distichum L., Ammannia baccifera L. and Ludwigia prostrate.Its control level of Spirogyra sp.,and L. minor ,based on coverage,and that of P. distichum,A. baccifera and L. prostrata ,based on fresh weight,reached 84.9%~98.7% at 45 days after application. This was significantly higher than the control obtained with 189 g/hm^2 clomazone 480 g/L EC,110 g/hm^2 metolachlor 720g/L EC or 500 g/hm^2 prometryn 40% WP. Necrotic spots from drift of the applied mixture to lotus leaves at the different application concentrations were obvious more than the control by visual measurement 15 days after application. But no obvious phytotoxicity symptoms such as chlorosis,malformation or organ distortion on the standing lotus leaves and stems developed. The yield increased by over 20% when the herbicide mixture was used under 4 dosages compared with the black control treatment. The yield of 630 g/hm^2 in the clomazone-metolachlor-prometryne treated area increased by 36.5% compared with the black control,and was not different to that obtained when manual weeding was used. The weed control efficacy of the herbicide mixture was significant when the lotus leaves were above the water for 20~30 cm,and its economic and effective dosage was 630 g/hm^2.