1 白粉病的症状 小麦白粉病主要为害叶片。严重发病时,叶鞘、茎杆及穗部都会受害。受害植株最初在叶片的表面发生白色霉点,以后逐渐扩大为圆形或椭圆形的白色霉斑,上有一层白粉(孢子堆),所以称为白粉病。白粉病主要影响叶片光合作用,发生严重时造成小麦结实粒减少,籽粒秕瘦,千粒重下降,减产25％左右。 1 symptoms of powdery mildew Wheat powdery mildew is the main damage leaves. Serious disease, leaf sheath, stem and ear will suffer. The diseased plants were initially white mildew on the surface of the leaves, and later gradually expanded into round or oval white mildew with a layer of white powder (spore heap), so called powdery mildew. Powdery mildew mainly affects the photosynthesis of leaves. In severe cases, the grains of wheat are reduced, the grains are lean and the grain weight is reduced. The yield is reduced by 25%.