leaf disease of orchid

[symptoms] cause mosaic or necrosis on the new leaves of the orchid, or chlorotic stripes on the veins of the orchids, resulting in local necrosis on Cartland's inoculated leaves; if co-infected with TMV-O, the bud produces brown necrosis. It can make Dendrobium produce flowers and leaves.

[pathogen] Cymbidium mosaic virus (CymbidiummosaicPotexvirus,CymMV). It belongs to the genus Potato virus X. The virion is linear, 476nm × 18nm. The viral genome is 6227nt. The content of nucleic acid RNA is 6%. The settlement coefficient is 144s. The lethal temperature was 65-70 ℃, the dilution end point was 60 ppm, and the in vitro survival time was 7-30 days at room temperature.

[incidence regularity] Juice infection. Peach aphids can transmit poison. The virus was preserved for a long time in diseased leaf sap and lost its pathogenicity in some orchid varieties for 2 months. Orchid plants with virus will be poisonous for life, and new buds will also be infected with virus. if healthy and disease-free seedlings are planted in peat pots and peat soil where poisonous orchids have been planted, the plants are prone to disease.

[prevention]

For some valuable virus-free orchids, ⒈ must be isolated from the orchid production base.

⒉ prevents the spread of the virus during cultivation. In gardening operations such as ramets and turning pots, fingers and tools have to be re-sterilized every time they are planted. Cannot be washed in the same container, the root should be washed with running water. Peat, moss and gravel used for orchid culture should be disinfected.

⒊ controls aphids. The commonly used pesticides are 50% malathion EC 1000 times, or 40% dimethoate EC 1000-1500 times, or compound fruit EC (dichlorvos 40%, omethoate 10%) 2000-3000 times, etc.