基于沉积量和生物效果的甘蓝小菜蛾防治喷雾参数优化

Spray parameter optimization based on the amount of pesticide deposition and its biological effect on cabbage diamondback moth

为明确不同喷雾参数对农药在甘蓝叶片表面的沉积和药剂生物效果的影响,在自走式喷雾塔内模拟田间喷雾条件,采用正交试验和单因子试验评价了喷头、喷液表面张力、施液量、喷雾压力及喷雾高度5个因子的影响程度及各因子间的相互作用,并采用响应曲面法优化了喷雾参数。结果表明：相较于喷头和喷雾高度,喷液表面张力、施液量和喷雾压力极显著影响农药沉积和药剂生物效果,其中喷液表面张力的影响最大;基于后3个指标以响应曲面法建立的甘蓝叶片表面农药沉积和苏云金芽胞杆菌防治小菜蛾生物效果的回归模型经验证准确有效,相关系数分别为0.9731和0.7790,能够用于预测农药沉积量和药剂生物效果。综合考虑防治甘蓝小菜蛾喷雾作业过程中的实际情况及成本控制,设定和调节目标函数满足单位面积农药沉积量大于4.0μg/cm2,且苏云金芽胞杆菌防治小菜蛾死亡率大于80%,获得苏云金芽胞杆菌防治甘蓝小菜蛾喷雾参数的优选范围为：Silwet-408助剂浓度13.50-44.00 mg/L、喷雾压力0.2-0.6 MPa、施液量300-717.6 L/hm2。

To identify the effect of different spray parameters on the pesticide deposition and biological effect on the surface of the cabbage leaves,field spray conditions were simulated in the self-propelled spray tower. Orthogonal test and single factor test were adopted to evaluate the effect of nozzle,the solution surface tension,application rate,spray pressure and spray distance. The interaction between different affecting factors was also analyzed. The response surface method was conducted to optimize spray parameters. The results showed that the spray liquid surface tension,application rate and spray pressure significantly affected the pesticide deposition and biological effect and the influence degree of the surface tension was the highest. Regression models of pesticide deposition on cabbage leaf surface and control effect of Bacillus thuringiensis on diamondback moth were proved to be accurate and effective,and could be used to predict pesticide deposition and biological effect. The correlation coefficients were 0. 9731 and0. 7790,respectively. Considering the spray process for cabbage diamondback moth and the actual situation of control cost,the objective function were set and adjusted to meet pesticide deposition weight per unit area of greater than 4. 0 μg / cm2,and the control effect of B. thuringiensis of greater than 80%.The optimization range of additives concentration,spray pressure and application rate were 13. 50-44. 00 mg / L,0. 2- 0. 6 MPa and 300- 717. 6 L / hm2,respectively.