大棚栽培,相对封闭,昼夜温差大,相对湿度高,植株上易凝结水滴,形成水膜,为喜湿性黄瓜霜霉病害发生,发展和危害提供了有利条件。一旦病害发生,一般减产15～20％,严重的可达50％以上。近年各地已摸索出一条生态防治的方法。 一、科学调节大棚温、湿度。生态防治,要抓住外界最低温度稳定在10℃以上到大通风之前这段时间,科学调节棚内温湿度。上午将棚温控制在30～35℃,相对湿度65～75％。室内温度大于35℃,开始放风,上午保持22～28℃,相对湿度60％;晚间温度下降,湿度上升,超过95％时,叶面渐渐形成水珠,这时要通风排湿,缩短 Greenhouse cultivation, relatively closed, large temperature difference between day and night, high relative humidity, easy to condense water droplets on the plant to form a water film, for hygromycin cucumber downy mildew disease occurrence, development and damage provided favorable conditions. Once the disease occurs, the general reduction of 15 to 20%, a serious up to 50%. In recent years, various localities have worked out an ecological prevention and control method. First, the scientific regulation of greenhouse temperature and humidity. Ecological prevention and control, we must seize the lowest outside temperature stable at above 10 ℃ to large ventilation during this period, the scientific regulation of greenhouse temperature and humidity. Morning shed temperature control at 30 ~ 35 ℃, relative humidity 65 ~ 75%. Room temperature is greater than 35 ℃, began to wind, the morning to maintain 22 ~ 28 ℃, relative humidity 60%; night temperature drop, humidity rises, more than 95%, the leaves gradually formed water droplets, then to ventilation and wetting, shortening