【摘要】 以草铵膦、百草枯和草甘膦3种灭生性除草剂进行桑园杂草防除试验,以及对家蚕的毒性试验,评价新一代除草剂草铵膦的药效和安全性。200 g/L草铵膦AS 150倍、100倍和75倍稀释药液对桑园杂草的田间防除效果与30%草甘膦AS150倍稀释药液相近(P>0.05),均优于200 g/L百草枯AS 100倍稀释药液(P<0.01),除草的速效性明显优于30%草甘膦AS150倍稀释药液,持效期在30 d以上,比200 g/L百草枯AS 100倍稀释药液明显延长。200 g/L草铵膦AS对家蚕3龄起蚕的24 h急性经口毒性(LC50)为421.366 2 mg/L,其毒性高于30%草甘膦AS(LC50>6 000 mg/L),低于200 g/L百草枯AS(LC50=194.828 2 mg/L)。用200 g/L草铵膦AS 150倍、100倍和75倍稀释药液直接喷洒桑叶后3 d左右采叶养蚕,家蚕仍表现出明显的药害症状;喷药后4~5 d桑树叶片枯黄,在桑叶上的残毒期>5 d。建议在桑园使用200 g/L草铵膦AS 150倍稀释药液,应定向对杂草茎叶部位均匀喷雾,避免喷洒到桑树枝干和叶片,喷药后5 d内勿采叶养蚕。更多还原

【Abstract】 The control efficacy and security of novel herbicide glufosinate was evaluated by comparing the control efficacy on weeds in mulberry field and its toxicity to silkworm( Bombyx mori) with two other sterilant herbicides,paraquat and glyphosate. The field control efficacy of 150 times,100 times and 75 times dilution of 200 g/L glufosinate aqueous solution( AS) were close to that of 150 times dilution of 30% glyphosate AS and were superior to that of 100 times dilution of 200 g/L paraquat AS( P<0. 01),and the quick acting weeding effect of glufosinate diluted solutions was much better than that of 150 times dilution of 30% glyphosate AS. The efficacy period of glufosinate diluted solutions lasted more than 30 days,which was longer than that of 100 times dilution of 200 g/L paraquat AS. Acute oral toxicity( LC50)of 200 g/L glufosinate AS to the 3rd instar newly exuviated silkworm larvae at 24 h was 421. 366 2 mg/L,which was higher than that of 30% glyphosate AS( LC50> 6 000 mg/L),but lower than that of 200 g/L paraquat AS( LC50=194. 828 2 mg/L). Apparent toxicity symptoms of silkworm larvae still occurred after being fed with mulberry leaves harvested at day 3 after directly spraying with 150 times,100 times and 75 times dilution of 200 g/L glufosinate AS.And yellow mulberry leaves appeared at day 4 to day 5 after spraying,showing that its residual toxicity period lasted more than 5 days in mulberry leaves. It is recommended to directly spray 150 times dilution of 200 g/L glufosinate AS onto stem and leaves of weeds evenly in mulberry field,avoid spraying herbicides onto mulberry branches and leaves,and not to harvest mulberry leaves to feed silkworm larvae within 5 days after spraying.更多还原