三种防治梨蚜的植物质农药王东昌（莱阳农学院山东２６ｏ２００）１蓖麻杆将扒除纤维的干蓖麻杆粉碎，即为原粉。把原粉加２０倍４０℃左右的清水，焖泡６小时，过滤弃渣，即成原液。施用时，把原液稀释８０～１００倍，在梨树卷叶前均匀弥雾，防效可达９０％左右；且对山... Three kinds of pest control plant pest pesticides Wang Dongchang (Laiyang Agricultural College, Shandong 26o200) 1 castor rod will be stripped of fiber dry castor rod smash, that is, the original powder. The original powder plus 20 times 40 ℃ water, simmer soak 6 hours, filtered residue, that is, the original liquid. When applied, the stock solution diluted 80 to 100 times, evenly in the pear volume before the leaf mist, anti-effect up to 90%;