论文部分内容阅读
1 大发生原因1.1 梨木虱基数过高 越冬成虫数直接影响来年的发生程度。一般来说 ,梨树萌芽前喷施 1次 3～ 5°Be石硫合剂防治越冬害虫 ,能明显降低越冬成虫基数。而果农为节省资金或过分信赖其它药剂 ,取消了这次用药 ,造成越冬成虫基数过大 ,夏季为害严重。1.2 药剂使用不
1 large causes 1.1 pear lice base number is too high The number of overwintering adults directly affect the degree of occurrence in the coming year. In general, pear sprouting before spraying a 3 ~ 5 ° Be lime sulfur agent to control overwintering pests, can significantly reduce the number of overwintering adult. The fruit farmers to save money or over-reliance on other agents, canceled the medication, resulting in overwintering adult base number is too large, serious damage in summer. 1.2 Pharmacy use not