一、苗期 这是蔬菜病害最易发生的时期。苗期病害主要有真菌引起的立枯病、猝倒病和灰霉病,此外还有低温和土壤湿度过大引起的沤根病。对于苗期病害的防治要做到以下几方面。 1.种子要进行消毒处理,保证种子不带病菌。 2.苗床要用无病新土并用药剂处理,防止苗床带菌。 3.控制苗床浇水,防止苗床因湿度过大引起病害发生。 4.早春育苗注意苗床保温,防止冷冻害侵袭。 5.加强苗床管理,培育壮苗,提高抗病能力。 6.发现病苗及时拔除,立即用药防治。 二、开花结果期 这是蔬菜病害第二个易发期,此时病害极易造成大流行,对产量影响很大,是蔬菜病害防治最关键时期。发病主要原因是蔬菜由营养生长转入生殖生长, First, seedling This is the most likely period of vegetable diseases occurred. Seedling diseases are mainly caused by fungi blight, damping off and gray mold disease, in addition to low temperature and soil moisture caused by Rhizoid Root Disease. Seedling disease prevention and control to do the following aspects. 1. Seeds should be disinfected to ensure that the seeds without bacteria. Seedbed to use disease-free new soil and pharmaceutical treatment to prevent seedbed with bacteria. 3. Control of seedbed watering to prevent seedbed caused by excessive humidity caused by disease. 4. Early seedling attention seedbed insulation to prevent the invasion of freezing damage. 5. Strengthen seedbed management, nurturing strong seedlings, improve disease resistance. 6. Timely removal of diseased seedlings found immediately medication control. Second, the flowering period This is the second susceptibility issue of vegetable diseases, this disease can easily cause pandemic, a great impact on the yield, is the most critical period of disease prevention and control of vegetables. The main reason is the incidence of vegetables from vegetative growth into reproductive growth,