一、蔬菜病虫的发生和防治1、蔬菜病虫害的发生。我县近年蔬菜种植面积的不断扩大、种类的增加和保护地面积的增加,为病虫害的发生提供了丰富的寄主及良好的生存和越冬条件,造成病虫害的发生面积逐年扩大,程度不断加重,情况越来越复杂。我县常发的蔬菜病害有霜霉病、菌核病、灰霉病、炭疽病、疫病、枯萎病等,虫害有菜青虫、小菜蛾、甜菜夜蛾、潜叶蝇等,一些生理性病害和杂草也给蔬菜生产造成很大损失。根据近年来病虫发生面积和造成损失分析,蔬菜病虫的发生为害具有以下几个特点:(1)潜叶绳、夜蛾科害虫、土传病害、病毒病、细菌性和生理性病害等新病虫上升,为害加重且难于防治;(2)灰霉病、霜霉病、炭疽病、疫病及小菜蛾、螨 First, the occurrence and prevention of vegetable pests 1, the occurrence of vegetable pests and diseases. In recent years, the planting area of ​​vegetables in our county has been constantly expanding, the increase of species and the increase of protected areas have provided abundant hosts and good conditions for survival and overwintering for the occurrence of pests and diseases, resulting in the pest and disease occurrence area expanding year by year, and the situation is aggravating More and more complicated. Vegetable diseases in our county are downy mildew, sclerotinia, gray mold, anthracnose, blight, blight, pest cabbage caterpillar, diamondback moth, beet armyworm, leaf miner, some physiological diseases Weeds and weeds also cause great losses in vegetable production. According to the pest occurrence area and the loss analysis in recent years, the occurrence of pests and diseases of vegetables has the following characteristics: (1) Latent leaf worms, noctuid pests, soil-borne diseases, viral diseases, bacterial and physiological diseases, etc. New pests rise, aggravating harm and difficult to control; (2) Botrytis, downy mildew, anthracnose, blight and diamondback moth, mites