What about the rotten heart of new orchid seedlings?

The "rotten heart" of new orchid seedlings is caused by black rot, and the pathogen is rot mold. "broken heart" disease focuses on prevention, the main measures are as follows. The new leaves of Cymbidium seedlings will cause "rotten heart" when they are stained by acid rain, heavy rain and continuous rain. After new buds open leaves, due to improper watering methods, there may also be a "bad heart". Therefore, we should pay attention to cover the rain, soak the basin or water from the side of the new seedlings as far as possible to prevent the heart of the new seedlings from dripping. Insecticidal insects, red spiders, thrips, aphids, slugs, snails and other pests like to suck the leaf juice of the new seedlings, and after biting the leaves, the leaves of the new seedlings are very easy to be infected with Pythium and cause "rotten heart". Quinathion, omethoate, promethazine, thiophanate, carbendazim and other insecticidal agents can be used to kill insects, such as quinathion, omethoate, carbendazim and so on. The excessive use of hormones in thin fertilizer and the over-dose use of chemical fertilizer, "Orchid King" and other fertilizers led to the imbalance of nitrogen, phosphorus and potassium needed for the growth of orchids, lack of trace elements, excessive growth of new seedlings and soft petiole paralysis. In light cases, scorched leaf footing shell; in severe cases, tissue necrosis, browning and blackening appeared in the heart of new seedling leaves. Therefore, it is necessary to use fertilizer according to the standard and apply thin fertilizer diligently. The leaf heart of the watered new seedling is very young, and the temperature difference between the water used for watering the orchid and the leaf surface temperature of the orchid is too large, which is very easy to "scald" the leaf heart of the new seedling and cause the "rotten heart". Therefore, the water used for watering orchids should be parked for a period of time so that the water temperature is close to that of orchid leaves; in hot seasons, water should be watered in the morning and evening as far as possible, and do not use tap water directly in the afternoon when the temperature is high. In the hot and breathable season, it is hot and humid, the ventilation is not smooth, and the base of the new seedling is not breathable, which can easily induce "rotten heart" disease. Therefore, when the orchid garden temperature exceeds 30 ℃, it must be shaded and cooled to maintain internal and external air circulation, and the humidity should be controlled at about 75%. The cultivated soil should be loose and breathable, and the base of the new seedling should not be buried too deep, and the Reed head of the new seedling should be slightly exposed.