Preliminary Study of 4 Spray-adjuvants on The Reduction of Herbicide Application in Cotton Fields of Early Maturing Cotton Region in Northern Xinjiang

【Objective】 To study the reduction and synergistic effects of spray-adjuvants on herbicide, in the hope of providing theoretical support for reducing the dosage of herbicide in the field. 【Method】 Field plot experiments were conducted to reduce the amount of soil-applied herbicides 50% Flumioxazin WP and 33% Pendimethalin EC by 20% and 30% respectively, and then 4 kinds of spray-adjuvants such as Jijian, Anrongle, Maisi and Zengxiaowang were added to compare the control effects on weed and safety of cotton with the treatments of conventional dosage. 【Result】 It was safe for cotton growth that the dosage of herbicide was reduced by 20% and 30% respectively and then 4 kinds of spray-adjuvants were added. On 30 days after application of herbicide, adding 4 kinds of spray-adjuvants respectively after the dosage of herbicide was reduced 20% and 30%, the control effect on weeds was significantly lower than the conventional dosage. On 45 days after application of herbicide, there was no significant difference in weed control effect between the conventional dosage treatment and the treatments whose dosage of herbicide was reduced by 20% and 30% respectively with 4 kinds of spray-adjuvants added. On 60 days after application of herbicide, there was no significant difference in weed control effect between the conventional dosage treatment and the treatments whose dosage of herbicide was reduced by 20% with Jijian, Anrongle and Zengxiaowang added. The control effect was worse than the conventional dosage when the dosage of herbicide was reduced by 30% with 4 kinds of spray-adjuvants added. The control effect of the conventional dosage was 90.08%. The fresh weight control effect of the dosage of herbicide reduced by 20% and added 4 kinds of spray-adjuvants were more than 98.2%, which was higher than the conventional dosage. 【Conclusion】 The dosage of 50% Flumioxazin WP and 33% Pendimethalin EC are reduced by 20% and then Jijian, Anrongle and Zengxiaowang added, it is found that its control effect of weeds in cotton field is equivalent to the conventional dosage, and they are safe for cotton growth. The results remain to be studied before application in the vast fields.