1.霜霉病该病在我省7～8月发生最盛。高湿、低温是发病的重要原因。通风不良、偏施迟施氮肥、刺激葡萄抽新梢、延迟成熟、阶段性干旱、园中环境卫生差等都能加重病情。此病主要危害叶片、嫩梢和幼果。叶病初呈半透明水浸状斑点,后为淡绿至黄绿色不规则多角形病斑,清晨病斑背面有一层灰白色霉 1. Downy mildew disease in our province from July to August the peak. High humidity, low temperature is an important cause of the disease. Poor ventilation, late application of nitrogen fertilizer, stimulation of grape shoots, delayed maturity, stage drought, the poor environmental health in the park can aggravate the condition. The disease endanger leaves, young shoots and young fruit. Leaf disease early translucent flooding-like spots, after the light green to yellow-green irregular polygon lesions, early morning lesions have a layer of gray mold