一、几种常见病害的症状识别及影响发病的因素 1.疫病:苗期发病猝倒,成株期叶片发病呈暗绿色,一部分或大部分软腐,干燥后变为淡褐色,茎部与叶上症状相似,植株急速凋萎死亡,是生产上的毁灭性病害,以茎基部和分杈处茎变为黑褐色或黑色最为常见,是识别该病的重要 First, the symptoms of several common diseases identify and affect the incidence of factors 1. Blight: Cataplexy cataplasm onset, the incidence of adult leaves was dark green, part or most of the soft rot, become brown after drying, stem and Symptoms on the leaves are similar and the plant dies rapidly, which is a devastating disease on the production and is most commonly found in stems and bifurcation where the stems become dark brown or black and are important for identifying the disease