一、灰霉病１．发病条件与症状　此病主要为害花和幼瓜，多从开败的花侵入，使花腐烂，产生灰色霉层，以后由病花向幼瓜发展，使瓜顶尖褪绿，呈水浸状软腐、萎缩，病部生灰色霉层。此病由半知菌灰葡萄孢真菌侵染引起。病菌主要以分生孢子在土壤表层及病残体上越冬。分生孢子借? First, gray mold 1. Conditions and symptoms of disease The disease is mainly flower and cucumber damage, and more from the failure of flowers invaded, the flower decay, resulting in gray mold layer, after the disease to the development of young cucumbers, melon top green, was soaked in soft Rot, atrophy, disease gray mold layer. The disease caused by the half-known bacteria Botrytis cinerea infection. Pathogens mainly conidia in the soil surface and sick overwintering. Conidia borrow?