Study On Herbicide Mixing And Synergistic Adjuvant In Corn Field

In order to reduce the damage of weeds to corn yield and quality,and reduce the useage of herbicides in corn fields,field experiment to evaluate the application of pre-emergence herbicide mixed of reduction techniques in maize fields,indoor and field experiments were conducted to screen post-emergence herbicides nicosulfuron and mesotrione synergistic adjuvant and study the synergistic mechanism.The main findings are as followings:1.Application of Pre-emergence herbicides mixture can increase the control of weeds.In different application schedules,s-metolachlor 1152 g a.i./hm²+prometryne 450 g a.i./hm² and isoxaflutole 86.4 g a.i./hm²+atrazine 450 g a.i./hm²+acetochlor 562.5g a.i./hm² application had better control effect on weeds and increased yield of corn.Compared with the control atrazine-acetochlar of 2100 g a.i./hm²,the control effect of fresh weight of weeds increased from 2.52%to 56.13%on 28 days.the increase rate increased by 3.59%to 45.20%.2.The control efficacy of nicosulfuron and mesotrione on weed control were obviously increased by adding adjuvant.Nicosulfuron and mesotrione added rosin adjuvant and coconut oil adjuvant,compared with other adjuvant,can significantly increase the control effect on crabgrass and amaranthus retroflexus,and can reduce nicosulfuron and mesoquinone the ED₅₀ of crabgrass and amaranthus retroflexus,reduction rate is 22.48%⁵1.10%.3.Different additives had different effects on the efficacy of nicosulfuron and mesotrione on weed control and corn yield.In the field experiments,the addition of different adjuvant to nicosulfuron showed that the addition of coconut oil adjuvant was better than the addition of rosin adjuvant.The degree of synergism of mesotrione was opposite.Among them,under the condition of reducing the herbicide by 1/4,compared with the non-additive treatment,the growth rate of the fresh weight of the weeds treated with rosin and coconut oil was 1.12%²3.44%.The increase rate of nicosulfuron-added coconut oil adjuvant was 7.70%to 11.36%,and the increase rate of nigroxanthine-added rosin adjuvant was 0.72%to 16.47%.4.Additives improve the physical characteristics of herbicide solutions.Adding rosin adjuvant and coconut oil adjuvant can reduce the surface tension of nicosulfuron and mesotrione solutions,and increase the extended diameter,agument leaf retention of herbicide solution in a certain range.After the addition of rosin adjuvant and coconut oil adjuvant,the surface tension of the liquid decreased by 37.96%to 47.47%,the expanded diameterof the liquid increased by 46.15%to 59.09%,the agument leaf retention of herbicide solution increased by 72.72%to 132.95%.