MySheen

Brief introduction of anthracnose in Guolan

Published: 2024-11-05 Author: mysheen
Last Updated: 2024/11/05, Cymbidium anthracnose harms Cymbidium, Cymbidium, Jian Orchid, Cymbidium, Cold Orchid and other orchids, causing scorched black spots on leaves and fruits, and in serious cases, the whole leaves die. At the initial stage of the onset of the symptoms, the middle of the leaf showed a round, oval shape, and the leaf edge showed a semicircular reddish-brown spot. It occurs at the base of the leaf, and the whole leaf can die when the disease spot is large or the number is large. In the later stage, the center of the lesion became lighter and the upper chakra was longitudinally ruptured. The disease spot on the fruit is irregular, showing a long black-brown spot. The pathogen is caused by several fungi. According to the separation and training of Shanghai Landscape Research Institute

Cymbidium anthracnose harms Cymbidium, Cymbidium, Jian Orchid, Cymbidium, Cold Orchid and other orchids, causing scorched black spots on leaves and fruits, and in serious cases, the whole leaves die.

At the initial stage of the onset of the symptoms, the middle of the leaf showed a round, oval shape, and the leaf edge showed a semicircular reddish-brown spot. It occurs at the base of the leaf, and the whole leaf can die when the disease spot is large or the number is large. In the later stage, the center of the lesion became lighter and the upper chakra was longitudinally ruptured. The disease spot on the fruit is irregular, showing a long black-brown spot.

The pathogen is caused by several fungi. According to the isolation and culture of Shanghai Garden Research Institute, there are two kinds of Cymbidium (ColletorichumorchidearumAllesch) and Cymbidium brevifolium (C.orchidearumf.cymbidiumAllesch). The pathogen of anthracnose on cold orchid and cymbidium may be Cymbidium brevifolia, while the pathogen of anthracnose in Sichuan Chunlan, Jian Lan, Brahlan and Cymbidium is mostly Cymbidium sp..

According to reports in Beijing, the pathogen of orchid gangrenous disease is also Gloeosporium. The conidia of Orchidaceae are round, small and black, and the leaves are borne on both sides. Bristles black and brown, separated 3-4, straight or slightly curved, tip sharpened, size 50-100mm 3-5 microns. The conidia are cylindrical, 12-20 μ m in size, 4-6 microns in size, slightly smaller at one end, transparent and colorless, unicellular, with oil globules or granular inclusions. Conidiophores thick and short. The optimum temperature for the growth of the pathogen was 25 ℃. The optimum temperature for sprouting is 25-30 ℃.

 
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