Efficacy of Cyanazine·Atrazine 30%SE and Sulcotrione·Atrazine 30%SC on Weeds and their Selectivity to Maize

The weed control efficacy and selectivity of the herbicide mixtures cyanazine·atrazine 30% SE and sulcotrione· atrazine 30% SC were compared at different growth stages of maize with the standard herbicide atrazine 90% WG applied to soil between sowing and emergence in a field experiment. Both sulcotrione·atrazine 30% SC( 1 575 g a. i. / hm2) sprayed at the 3 ~ 7 leaf stage and cyanazine·atrazine 30% SE( 1 350 g a. i. / hm2) at 3 ~4 leaf stage not only provided adequate weed control but also increased corn yield by more than 10% over a control treatment with only water. Their effects weed in control and yields increase were better than those of atrazine 90% WG applied to soil between sowing and emergence. Cyanazine·atrazine at the same dose,however,was not safe to maize at 6 ~ 7 leaf stage,and both weed control and crop yield were inferior ro those achieved with 2 160 g a. i. / hm2atrazine.