硫双威在棉花和土壤中的残留动态研究

为了制订硫双威在棉花上安全使用标准，采用田间试验方法研究了硫双威在棉叶上和土壤中的残留动态，应用ＧＬＣ法测定了棉叶、棉籽和土壤中的残留量。试验结果表明，硫双威在棉叶和土壤中的半衰期分别为３ｄ和９ｄ。施药量（有效成分）为６７５ｇ／ｈｍ２和３３７．５ｇ／ｈｍ２，施药３次，末次施药距采样间隔３０ｄ，硫双威在棉籽中残留量分别为０．０７５－０．１０３ｍｇ／ｋｇ和０．０５５－０．０６９ｍｇ／ｋｇ，在土壤中残留量分别为０．１５６－０．１８７ｍｇ／ｋｇ和０．０３０－０．０４５ｍｇ／ｋｇ。硫双威属易降解农药（Ｔ１／２＜３０ｄ），按推荐计量（３３７．５ｇ／ｈｍ２）使用３次是安全的

Study on the Residual Dynamics of Thiodicarb in Cotton and Soil.

In order to make up the standards for safe use of thiodicarb on cotton,a field experiment was conducted to study the residual dynamics of thiodicarb in soil and leaves of cotton.The residues of thiodicarb in soil,cotton seed and leaves of cotton were determined by GLC.The trial results showed that the half lives of thiodicarb in soil and leaves of cotton were 9 and 3 days,respectively.The cotton was sprayed three times with thiodicarb(37 5%MPC)at the rate of 675g a .i/hm 2 and 337.5 g/hm 2.At 30th day after the last application,the final residues of thiodicarb in cotton seed were 0.075 0.103 mg/kg and 0.055 0.069mg/kg respectively.The final residues of thiodicarb in soil were 0.0156 0.187mg/kg and 0.030 0.054mg/kg respectively. Thiodicarb is a pesticide of easy dissipation (T 1/2 <30d). It is safe if applied 3 times at a recommended rate(337.5g a .i/hm 2)