采用浸叶法测定川楝素与吡虫啉对瓜蚜2龄若虫的毒力,筛选复配的最佳配比,并测定复配剂的共毒系数.结果表明,在11个配比处理中,川楝素与吡虫啉的质量比分别为3:7、4:6、5:5的毒效比分别达到1.81、1.90、1.90,明显高于其他组,3组复配剂均具有明显的增效活性;对上述3组复配剂进行室内毒力测定,求出各自的回归方程和半数致死浓度(median lethal concentration,简称LC50),结合川楝素与吡虫啉2种单剂的LC50,测得3种复配剂的共毒系数分别为219.46、331.77、220.37,均大于100,为增效复配.综上所述,川楝素与吡虫啉的质量比为4:6时共毒系数可达331.77,增效作用最大,为最佳配比.

The disease occurrence and resistance of the 31 eggplant cultivars to eggplant gray mold disease have been investigated and evaluated under nature condition. The results showed that 31 eggplant cultivars have all been infected by Botrytis cinerea , The disease incidence of Heichang eggplant was the highest, which attained 77.8%, the incidence of Zhaowubangmo eggplant was the lowest,which was 10%. The resistance evaluation results showed that three eggplant cultivars including Yachenghong eggplant, Tgheimeiren and JinqieA were high susceptible cultivars to gray mold, the percentage of the susceptible cultivars was 9.68%, the percentage of the middle susceptible cultivars and middle resistance were 19.35% and 32.26% respectively. The results also showed that eleven high resistance cultivars including Zhaowubangmo eggplant and Dukou eggplant have been screened from the 31 eggplant cultivars, the percentage of which was 35.48%.