Leaf spot of Cateran flower

① harm: this unknown species of Cercospora fungi can infect the following genera: Brassavola,Epicattleya,Epidendrum.

② symptoms: the disease is characterized by slightly sunken purple-black tiny spots on the back of the leaves, the diameter of which is generally less than 1mm, this disease spot is the result of bacteria invading from the stomata on the back of the leaves, often all leaves are sick, resulting in many discontinuous tiny disease spots, greatly weakening the growth of diseased leaves. The corresponding part of the front of the leaf is yellowish green, and the oldest leaf is usually the most seriously infected. However, the leaves that are not fully mature will also suffer from the disease, and the seriously diseased leaves will fall off.

Prevention and treatment of ③: 1O00 times solution was prepared with 50% wettable powder and sprayed with a small amount of wetting agent, once every 2 weeks, for a total of 3 times, and then sprayed once a month if necessary. (Liu Zhongjian)