氰氟草酯使用技术对双穗雀稗防除效果的影响

摘要

为明确氰氟草酯防除双穗雀稗的最佳使用技术,采用室内试验和田间试验相结合的方法,明确氰氟草酯在不同施药情况下对双穗雀稗的防除效果.室内试验结果表明,氰氟草酯对双穗雀稗具有较好的防除效果,LD50为有效剂量26.15 g/hm2;田间试验结果表明,在全株受药情况下,施用10％氰氟草酯乳油有效剂量90～270 g/hm2对苗期至营养生长盛期双穗雀稗均具有较好的防除效果,防除效果接近100％.室内和田间不均匀施药试验结果表明,双穗雀稗喷施氰氟草酯部分防除效果较理想,未施药部分防除效果随着施药部分剂量的增加而增加.总体来讲,施药不均匀是导致防除效果波动的一个主要原因.在施药均匀、全株施药的情况下,10％氰氟草酯乳油有效剂量90 g/hm2对双穗雀稗具有很好的防除效果,在不能保证均匀全株受药的情况下,10％氰氟草酯乳油防除双穗雀稗的使用剂量应该提高到有效剂量270 g/hm2.%To clarify the control efficacy of cyhalofop-butyl on Paspalum distichum,laboratory experiments and field trials were carried out under different treatment conditions.Laboratory experiment results indicated that cyhalofop-butyl presented good control effect on P.distichum with the LD50 values of 26.15 g/hm2 effective dosage.Field trials demonstrated that from seedling stage to vegetative growth peak stage,spraying of herbicide on whole plant at effective dosage of 90 to 270 g/hm2 had approximate 100％ control effect.Non-uniform application in both laboratory and field showed good control efficacy in sprayed area,but control effect in non-sprayed area is dose-dependent.In general,non-uniform application was one of the main reasons for control efficacy decreasing.10％ cyhalofop-butyl EC with the effective dosage of 90 g/hm2 would achieve significant control effect on P.distichum under uniform spray on the whole plants,while the dosage should be increased to 270 g/hm2 when proper spraying can not be guaranteed.