除草剂土壤处理对旱直播稻田杂草的防除效果

目的]筛选对旱直播稻田杂草具有较好防除效果的土壤封闭除草荆。方法]研究了4种除草剂土壤封闭处理对旱直播稻田阔叶草、禾本科杂草、莎草的防除效果。结果]除360g／L异嗯草松CS（广灭灵）对秧苗前期生长有点影响外，50％二·苄·异WP、35％丙·苄WP、42％丁·恶EC对水稻安全性较好。4种药剂对旱直播稻田杂草有较好的防效，药后45d，50％二·苄·异WP1500、1800g／hm^2 2个处理对禾本科杂草的株防效为92．31％～94．51％，对阔叶草的株防效为93．48％^-97．19％，对莎草的株崎效为97．44％～97．68％；35％丙·苄WP1200g／hm。对莎草的株防效为97．4‘4％；42％丁·恶Ec1650ml／hm^2对禾本科杂草的株防效为97．80％；360g／L异嗯草松CS750ml／hm^2对禾本科杂草的株防效为98．90％，但对阔叶草和莎草只有抑制作用。结论]为旱直播稻田杂草的有效防除提供了理论依据。

Control Effect of Soil-applied Herbicides to Weeds in Paddy Field of Dry Direct Seeding

Objective ] The aim was to screen out soil-applied herbicides which had good control effects to weeds in paddy field of dry direct seeding. Method] Control Effects of four kinds of soil-applied herbicides to weeds （ bread-leaf weeds, monocotyledonous weeds and sedges） in paddy field of dry direct seeding were studied. Result] Except that 360 g/L Clomazone CS had certain effect on the growth of seedlings at early stage, 50% Pendimethalin ~ bensulfuron methyl ~ isoproturon WP, 35% Pretilachlor bensulfuron methyl WP and 42% Butachlor-oxadia- zon mixture EC were safe to rice. The four herbicides had good control effects to weeds in paddy field of dry direct seeding. After 45 days, 1 500 and 1 800 g/hm2 treatments of 50% Pendimethalin ~ bensulfuron methyl ~ isoproturon WP had 92.31% -94.51% of stem control effect on monocotyledonous weeds, 93.48% -97.19% of stem control effect on broad-leaf weeds and 97.44%-97.68% of stem control effect on sedges, respectively ; the 1 200 g/hm2 treatment of 35% Pretilachlor bensulfuron methyl WP had 97.44% of stem control effect on sedges ; the 1 650 ml/hm2 treatment of 42% Butachlor-oxadiazon mixture EC had 97.80% of stem control effect on monocotyledonous weeds; the 750 ml/hm2 treatment of 360 g/L Clomazone CS had 98.90% of stem control effect on monocotyledonous weeds, but had inhibition to broad-leaf weeds and sedges. Conclusion] The research results provide theoretical basis for the coefficient controi of weeds in paddy field of dry direct seeding.