Causes and Prevention of Heart failure of New Orchid seedlings

The heart rot of new orchid seedlings is caused by black rot, and the pathogen is rot mold. When it is found that the new orchid seedlings have a broken heart, there is no cure, which makes the hearts of those who love orchids heartache. Prevention is the most important thing in rotten heart disease. After several years of observation and practice, the author talks about some understanding for reference only.

(1) Water damage: the first rain after a long drought is mostly acid rain with dust pollutants; the torrential rain in the hot season makes the orchid seedlings soak in the water for a long time; the continuous drizzle in spring and autumn makes the orchid seedlings in a high wet state for a long time. When the new leaves of orchid seedlings are stained by acid rain, heavy rain and continuous rain, the new seedlings will have a bad heart. After the opening of the new bud, due to the improper watering method, it is directly poured down from the top of the new leaf, and the water stays in the leaf center for too long, and a rotten heart may also occur. Therefore, attention should be paid to shelter from the rain, and soaking basin or watering from the side of the new seedling should be used as far as possible to prevent the heart of the new seedling from dripping.

(2) insect pests: shell insects, red spiders, thrips, aphids, slugs, snails and other pests, they like to suck the leaf juice of new seedlings, and after biting the leaf heart, the leaf center of new seedlings is very easy to be infected with Pythium and cause rotten heart. Can be used to spray parathion, omethoate, can be killed, topazine, carbendazim and other insecticidal, fungicides regular preventive spraying.

(3) Medicine and fertilizer damage: excessive use of hormones and over-dose use of chemical fertilizer. Orchid King and other fertilizers, orchid growth of nitrogen, phosphorus, potassium out of balance, lack of trace elements, new seedlings grow crazy, 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, avoid greed, must not be eager for quick success and quick profit, according to the standard requirements of the appropriate use of medicine, so that thin fertilizer diligent application.

(4) scald: the leaf center of the new seedling is very young, and the temperature difference between the water used for watering orchids and the leaf surface temperature of orchids is too large. when the temperature difference exceeds 10 degrees, it is very easy to scald the leaf center of new seedlings, and then it is eroded by Pythium, causing rotten heart. Therefore, the water for watering orchids should be parked in the orchid garden for a period of time so that the water temperature is close to that of the orchid leaves; in the hot season, it should be watered in the morning and evening as far as possible, and should not be directly watered with tap water when the temperature is high in the afternoon.

(5) airtight: it is hot and humid in hot season, which is a frequent period of rotten heart disease. Languo high temperature, high humidity; if the ventilation is not smooth, the base of the new seedling is not breathable, it is very easy to induce rotten heart disease. Therefore, when the temperature in Lanzhou exceeds 30 degrees, we should pay special attention to management. The orchid garden should be shaded and cooled, 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.