三、菜豆根腐病 1.症状 早期症状不明显,仅表现植株较矮小,结荚后症状渐明显,病株下部叶子发黄,边缘产生大小不等的黑色枯斑,茎基和根部病斑深褐色或黑色,稍凹陷。病株侧根少。主根腐烂,病株枯死。高温高湿易发病。 2.传染途径 主要是通过在病残体上过冬的病菌侵染。用病株 Third, the root bean rot 1. Symptoms of early symptoms are not obvious, only the performance of shorter plants, pod symptoms became apparent, yellow leaves lower part of diseased plants, the edge of the black and white spots of varying sizes, stem and root lesions Dark brown or black, slightly depressed. Stems less lateral roots. The main root rot, diseased plants withered. High temperature and humidity prone to disease. 2. The main route of infection is through the winter in the sick debris infection. With the sick strain