Main symptoms of bean rust

Bean can be infected with pathogen in the whole growing period, but the resistance weakens and the susceptibility increases during the period from the beginning of flowering to fruiting. The disease mainly affected the leaves, and in the early stage of the disease, there were little faded yellow and white spots under the leaves, and the spots gradually increased until the whole leaf was densely covered. The yellow-brown slightly raised scab spots were formed on the back of the disease spot, that is, the summer spore pile. After the rupture of the summer spore pile, a large number of summer spores were scattered, and sometimes a black winter spore pile was formed on the old leaves in the late growth stage. The leaves are withered and yellow, the plants are short, the pods are few and small, the growth period is shortened, and finally wither and die.