单季晚稻机插田化学除草技术

Chemical Weed-control Technique in Machine-transplanted Fields of Single Late Rice

[目的]随着小苗机插稻田面积的扩大,机插田草害发生也日益严重,为有效控制机插田杂草的危害,2008—2009年在浙江省桐庐县单季晚稻机插田进行不同施药时期和施药剂量对主要杂草防效试验。[结果]5%丁草胺GR 750 g a.i./hm2＋10%苄嘧磺隆WP 30 g a.i./hm2和20%乙.苄WP 90 g a.i./hm2在插后3 d施药,插后50 d对总草鲜质量防效极显著高于插后7 d的防效。53%苄嘧.苯噻酰WP 318、477、636 g a.i./hm2于插后5 d施药,药后30、50 d,对异型莎草、阔叶草、总杂草的防效有差异;而50%苄.丁.异丙隆WP 450、600 g a.i./hm2的防效差异均不显著;药后50 d对总草株防效均达93%以上、鲜质量防效99%以上,且增产8.2%~14.4%。上述处理除20%乙.苄WP 90 g a.i./hm2在药后15 d内对机插稻有一定影响外,其余均较安全。[结论]在小苗机插后3~5 d,使用5%丁草胺GR 750 g a.i./hm2＋10%苄嘧磺隆WP 30 g a.i./hm2或53%苄嘧.苯噻酰WP 318~636 g a.i./hm2,或50%苄.丁.异丙隆WP 450~600 g a.i./hm2拌肥或拌土150 kg/hm2能有效控制机插田杂草的为害,且对机插稻安全。

[Aims]With the increase of area of machine-transplanted rice fields,occurrence of weeds was also increasingly serious.Field efficacy of different spraying time and spraying doses to major weeds was evaluated in machine-transplanted fields in Tonglu county of Zhejiang province during the years of 2008 to 2009 in order to effectively control the damage of weeds.[Results] Field efficacy of the mixture of butachlor 5% GR 750 g a.i./ha and bensulfuron methyl 10% WP 30 g a.i./ha,and acetochlor·bensulfuron-methyl 20% WP 90 g a.i./ha sprayed on the 3rd day after machine-transplanting on fresh weight of total weeds were significantly higher than those on the 7th day after machine-transplanted for 50 days after machine-transplanting.On the 5th day spraying after machine-transplanted,control efficacy of bensulfuron methyl·mefenacet 53% WP at different doses（318,477,636 g a.i./ha） to C.difformis,broadleaved weeds and total weeds were different for 30 and 50 days after herbicide-spraying.While control effects of bensulfuron methyl·butachlor·isoproturon 50% WP at different doses（450,600 g a.i./ha） had no obvious difference to E.crusgalli,C.difformis,broadleaved and total weeds.Stem and fresh-weight control effect of the two herbicides treated with different doses to total weeds was more than 93 and 99% for 50 days after spraying respectively,and the increase of rice yield was 8.2-14.4%.Other herbicides above were safety to machine-transplanted rice plants,except acetochlor·bensulfuron-methyl 20% WP 90 g a.i./ha had some negative effect on rice for 15 days after spraying.[Conclusions] On the 3rd to 5th day after machine-transplanting,butachlor GR 750 g a.i./ha＋bensulfuron methyl WP 30 g a.i./ha,or bensulfuron methyl·mefenacet WP 318-636 g a.i./ha,or bensulfuron methyl·butachlor·isoproturon WP 450-600 g a.i./ha applied using toxic clay could effectively control the damage of weeds in machine-transplanting rice fields,and be safety to machine-transplanted rice plants.