How can orchid stem rot be prevented and treated more effectively?
About the prevention and treatment of orchid soft rot and stem rot and the medications used 15-09-21 Muzi Zhai 185+ follow Send flowers (0) Favorite
About orchid soft rot and stem rot. As summer arrives, various orchid diseases begin to run rampant, especially soft rot and stem rot, which are extremely harmful to orchids. They lie dormant easily, break out fiercely, and are hard to eradicate, turning your joy into nothing in an instant. First, you must distinguish whether it is soft rot or stem rot.
1. Soft rot. Soft rot is a bacterial disease. The symptoms start with the new shoots first. Its characteristic is that the base of the plant, from the inside out, turns black and soft with a foul odor, and the pseudobulb soft-rots. It is an acute disease. In the early stage of soft rot, tiny brown water-soaked spots appear on the leaves, then expand into black moist patches. At this point the lesions rupture very easily and exude a foul-smelling liquid. After that, the orchid plant quickly rots. This disease generally occurs easily in rainy and humid seasons above 30°C. To prevent "soft rot," you must first understand clearly that soft rot is a "bacterial disease," and medication must be targeted. The drugs for dealing with it are chloramphenicol, streptomycin and penicillin. Chloramphenicol has a broader antibacterial spectrum and stronger antibacterial power. Against "soft rot," thiophanate-methyl and carbendazim are useless.
2. Stem rot. Stem rot is a fungal disease. The symptoms start first with the parent generation or the generation before that. Its characteristic is that the base of the plant, from the outside inward, gradually turns yellow and withers and breaks off, and the pseudobulb turns yellow and hard, like a chronic disease. To prevent "stem rot," metalaxyl·mancozeb (made from a reasonable compound of metalaxyl and mancozeb) can be used. It is a low-toxicity fungicide with both protective and curative effects. Among them, metalaxyl is a systemic fungicide with protective and curative effects that can be absorbed by the roots, stems and leaves of plants and, as water moves within the plant, is transferred to various organs of the plant; mancozeb is a protective fungicide with a relatively broad fungicidal spectrum. You must focus on applying medication at the key periods. Soft rot generally occurs in the stuffy, humid, high-temperature and high-humidity months of June and July, as well as August at the turn of summer and autumn. Therefore, these three months are the key period for preventing and treating soft rot. Even if no disease is found, medication should still be applied weekly for prevention and treatment.