Leaf spot disease of Cymbidium and its related orchids

① harm: some orchids of Cymbidium and its related genera are often attacked by a fungus of the genus cauda, which is different from other fungi, and its hosts include many species and hybrids of the genus Cymbidium and Grammetophyllum.

② symptoms: the disease is characterized by tiny plaques on the back of the leaves, which are round, slightly sunken, dark brown, generally smaller than 1mm in diameter, and are often combined with more than two plaques. The corresponding part of the middle of the leaf was yellowish green at first, then turned brown, with a yellowish halo, and the disease of the old leaf was more serious.

Prevention and treatment of ③: 1000 times of solution was prepared with 50% wettable powder and sprayed with Xiaoxu wetting agent for 3 times, once every two weeks. If necessary, you can spray once a month in the future. If you use Formosa, the dilution ratio is 8OO, and an appropriate amount of developing adhesive is added. This product is an anti-infection agent and plays a protective role in plants. If the disease has become a problem, susceptible varieties should be sprayed every 2 weeks.

Liu Zhongjian