Control methods of Orchid Brown Rot

Orchid brown rot often occurs first in the new leaves, and its pathogen invades from the root. Purple or purple-brown spots first appear at the base of the leaves and on the pseudobulbs, which gradually appear waterlogged, and the spots also expand. After 3 to 5 days of the disease, the leaves became soft and dark brown, while the conducting tissue of the pseudobulbs blackened and soon rotted and fell off until the whole plant became black and withered. The pathogen is infected through the transport tissue of the pseudobulb and external contact, which will soon spread to the normal plants around the diseased plant, and can spread to the whole basin in a few days.

Orchid brown spot occurs more frequently on the seedlings of Cartland and Phalaenopsis.

First, the disease is easy to occur in the period of high temperature and heavy rain.

Second, the soil consolidation or water content is too large, and the air permeability is poor.

Third, fertilization is too thick or the amount of fertilizer is too large.

Fourth, the pseudobulb was mechanically damaged and the pathogen invaded.

The prevention of orchid brown spot should be more important than control, and the specific control measures are as follows:

First, June to August is a frequent period in the high temperature and rainy season. Orchids should be carefully observed every morning and evening to strengthen prevention. Once potted orchids are found to have disease spots, they should be immediately isolated from healthy orchids.

Second, maintain the ventilation of the cultivation environment, including the site and basin soil, often clean up the surrounding dead branches and leaves, and completely burn them, and spray disinfectant on platforms, greenhouses, roads, and pots.

Third, watering should be injected from the edge of the flowerpot to avoid watering, lest water droplets bring residual spores to other healthy plants, watering should be chosen at the easiest time to dry, to avoid watering too much, the pot soil is too wet, watering can not be poured into the leaf bundle.

4. When dividing plants, the cutting blade should be disinfected first, and the wound should be smeared with carbendazim powder or soaked in streptomycin solution for 60 minutes.

5. At the initial stage of the disease, 50% carbendazim powder 500 times or 100 times Bordeaux solution was sprayed 2 to 3 times.

Sixth, the diseased plant should turn the basin to change the soil, the diseased orchid culture soil can no longer be used, the damaged part of the diseased plant should be completely removed and burned, and the diseased plant and pot soil should be sprayed with Bordeaux solution every 10 days.