What is the disease of black spots on orchid leaves

1. What is the disease

Black spots on orchid leaves are usually caused by anthracnose. The disease initially causes black spots on the leaves which are small at first and then slowly expand, eventually causing the entire leaf to dry up. As one of the common diseases, in addition to treatment, certain prevention and treatment methods are also needed.

2. How to treat

1. Prune diseased leaves: Prune all the leaves with black spots on the orchid. Since anthracnose spreads so easily, be sure to avoid diseased leaves. After cutting off the diseased leaves, do not discard them casually. It is best to burn them collectively, which can also effectively sterilize them.

2. Drug sterilization: In addition to the bacteria on the leaves, there may also be residual bacteria in the potting soil for growing orchids. It is necessary to spray with insecticides such as Benomyl for treatment. If the situation is serious, the plants need to be removed and soaked in thiophanate-methyl solution for disinfection.

3. Replanting and maintenance: The disinfected orchid can be replanted in a new pot with new soil to avoid further infection by bacteria. After replanting, water it thoroughly and place it in a cool and ventilated place. Do not spray water in a short period of time as it is not conducive to wound healing. After that, spray disinfectant every few days, and it can usually be completely cured in about 20 days.

4. Subsequent prevention: The reason why orchids suffer from anthracnose is mostly due to a bad environment. It is necessary to strengthen the ventilation of the environment to avoid air stagnation, and at the same time, reduce the humidity appropriately. Humid air is the key to the breeding of bacteria. You can put some desiccant indoors to reduce humidity.