What are the main symptoms of rust disease in yardlong beans?
Yardlong beans can be infected by the pathogen throughout the entire growing period, but resistance weakens and susceptibility increases from the beginning of flowering to the podding stage. The disease mainly attacks the leaves. In the early stage of the disease, scattered chlorotic yellowish-white spots appear on the underside of the leaves, and the spots gradually multiply until they densely cover the entire leaf. On the corresponding reverse side of the lesions, yellowish-brown...
Yardlong beans can be infected by the pathogen throughout the entire growing period, but resistance weakens and susceptibility increases from the beginning of flowering to the podding stage. The disease mainly attacks the leaves. In the early stage of the disease, scattered chlorotic yellowish-white spots appear on the underside of the leaves, and the spots gradually multiply until they densely cover the entire leaf. On the corresponding reverse side of the lesions, slightly raised yellowish-brown scab-like spots form, namely the uredinia; after the uredinia rupture, large numbers of urediniospores are released, and black telia sometimes form on old leaves in the late growth stage. The leaves turn yellow, wither and drop off, the plants become stunted, the pods are few and small, the growth period is shortened, and finally the plants wither, become thin and die.