Safety and Weed Control Efficiency of Pyroxasulfone on Industrial Hemp
Laboratory bioassay and field experiments have been conducted by soil application test to determine the crops safety of pyroxasulfone and the weed control effects in industrial hemp ( Cannabis sa-tiva L.) field,and the impact of this herbicide on industrial hemp yield was evaluated. The results showed that:pyroxasulfone had high activity against barnyard grass ( Echinochloa crusgalli ) and Ama-ranth (Amaranthus retroflexus),GR50 were 20.51 g/hm2 and 27.05 g/hm2 respectively. Pyroxasulfone mainly inhibited the plant height and fresh weight of industrial hemp,barnyard grass and Amaranth,but promoted the elongation of roots. For industrial hemp,the selectivity index of pyroxasulfone to barnyard grass and Amaranth were 2.13 and 0.73. The results of the field experiment showed that the weed control effect in Fengyang,Xishuangbanna and Qinggang were 75.44％-90.37％ when the dosage of pyroxasul-fone was 75 g/hm2,and treated for 30 days. It also has a significant increase in yield of industrial hemp seed in all three areas,with an increase rate of 14.12％-22.41％. The above findings suggest that it is necessary to scientifically apply pyroxasulfone according to the species of weeds occurring in different are-as,and strictly control the dosage to prevent the occurrence of phytotoxicity.
pyroxasulfoneindustrial hempcrop safetyweed control effect
万方数据
维普
