2012-2016年稻田农药科学减量试验分析

Analysis on the scientific pesticide reduction trial in paddy field during 2012-2016

为了科学使用农药,采用Zisman图法测定不同生育期稻叶的临界表面张力,同时从喷洒次数、农药投入量、喷洒药液的表面张力、农药投入量毒性系数、病虫害的防治效果及水稻产量等角度比较了2012-2016年稻田喷施植物保护部门推荐的农药组(A)和实验室推荐的农药组(B)的差异性。结果表明,分蘖期至乳熟期稻叶正面和反面临界表面张力的平均估值分别为29. 94 m N/m和31. 01 m N/m,A组药液的表面张力均大于稻叶的临界表面张力; B组药液的表面张力均小于稻叶的临界表面张力。与A组相比,B组每年用药次数减少2～3次;总投入量每年减少38.96%～81.30%;有效成分用量减少58.75%～87. 10%;投入量毒性系数总和减少46.97%～93. 77%。田间防治效果表明,B组对稻纵卷叶螟、稻曲病和稻瘟病的防治效果相对较好,2种农药施用组对稻飞虱和纹枯病的防治效果相当;除稻瘟病发生年份外,2种农药施用组间水稻产量无显著差异。

In order to use pesticides scientificatly,the critical surface tension(CST)of rice leaf in different growth stage was determined by Zisman method.On the basis of spray times,total input of pesticides,surface tension of pesticides liquild sprayed in paddy field,actute toxicity coefficient of pesticide input,pest and disease control effect and rice yield,the differences between pesticide recommended by plant protection department(group A)and pesticide recommended by laboratory(group B)during 2012-2016 were compared.Results showed that the mean CST values of the abaxial and adaxial rice leaf surface from tillering stage to milk stage were 29.94 mN/m and 31.01 mN/m,respectively.The surface tension values of rice leaf in group A were more than the mean CST values of rice leaves.On the contrary,the surface tension values of rice leaf in group B were less than the mean CST values of rice leaves.Compared with those in group A,the spraying times in group B were reduced by two to three times per season in paddy field.At the same time,total input of pesticide formulations and pesticide active ingredient dosage in group B were decreased by 38.96%-81.30%and 58.75%-87.10%,respectively.The total actute toxicity coefficient of group B was 46.97%-93.77%less than that of group A.The control effect in group B against rice leaf folder,rice false smut and rice blast was relatively better than that in group A,and the two pesticide application groups had same effect on the control of rice planthoppers and rice sheath blight.Except for the year happened rice blast,there was no significant difference in rice yield between the two pesticide application groups.