影响烟嘧黄隆药效的因素

室内盆栽试验表明，烟嘧黄隆的药效受要草叶龄、助主施药与降不间隔时间的影响。从玉米田马唐防除的生态经济阈值和不同叶龄防产的综合结果看，以马唐３叶期后至５叶期前喷３６ｇ／ｈｍ＾２ 嘧黄隆效果最好。非离子型表面活性剂吐温２０、ＯＰ－１０、平平加１５和阴离子型表面活性剂洗衣粉都能显著提高烟嘧黄隆对马唐的防效，增效幅度在２８．６－５２．７％。渗透剂Ｔ和ＹＺ－９０１不能显著提高烟嘧黄隆的药效。施药后与降水的间

FACTORS INFLUENCING EFFICACY OF NICOSULFURON ON CRABGRASS (DIGITARIA SANGVINALIS)

Experiments conducted in greenhouse showed that the efficacy of nicosul-furon on crabgrass was affected by weed size, surfactants and rain interval. Results indicated that crabgrass control decreased dramatically at 7-leaf stage. According to the eco - economic threshold of crabgrass control in corn, treatment with nicosulfuron should be carried out under the dosage rate of 36g/hm2 during 3 through 5 leaf stage. The activity of nicosulfuron varied with surfactant. Tween20, OP-10, APE-15 and washing powder increased control efficacy on crabgrass, and the increment ranged from 28. 6% to 52. 7%, but Penetrator-T and YZ-901 did not affect the efficacy. To achieve higher efficacy must not be shorter than 8 hours after treatment, the rain interval after treatment influenced nicosulfuron activity.