Little-known facts about orchid disease prevention: do these few things and they will get sick less often

Diseases of young shoots

From April to September, during the young shoot growth period, if the leaf sheath is healthy but the base of the new leaf suddenly turns brown and rots away, this is because it has contractedsoft rotdisease. The way to prevent it is: do not let water remain on the young shoots. If the young shoot stops growing while still tender and black spots appear, this is caused by anthracnose. The way to prevent it is: spray an organic sulfur fungicide 1-2 times a month.

Diseases of leaves, roots, and petals

Anthracnose: after the temperature rises, irregular brown spots appear in the leaves and their area gradually expands, or swirl-shaped patterns appear, indicating anthracnose. The way to prevent it is: spray an organic sulfur fungicide 1-2 times a month.

Leaf blight: the leaf tip suddenly turns brown and dries up. Or the base of the leaf or the leaf sheath discolors and black spots appear around it, indicating leaf blight; when there is a problem with the roots, it is very easy to contract this disease. Spray an organic sulfur fungicide (Daconil) 1-2 times a month.

Withering disease: when some white spots, or yellow streaks or necrotic blotches, appear on the leaves, it indicates withering disease. This disease cannot be prevented with medication. Once a plant contracts it, it must be isolated immediately. Because this disease is easily transmitted through water, the practice of placing the pot in a bucket to soak, or managing plants under a shelf, must be stopped immediately to prevent the disease from spreading to other plants.

3. Soft rot: at high temperatures, the leaf base suddenly turns yellow-brown and the pseudobulb also rots away, indicating soft rot. The control method is to keep ventilation and drainage in good condition, and do not let water remain on the new shoots.

4. Southern blight: at high temperatures, white filaments appear near the leaf base or on the pseudobulb, and many brown granules are produced; this is a disease called southern blight, which can kill the entire plant in the blink of an eye and also causes white mycelium to appear around the roots. Because there is no medication that can treat it, once such a diseased plant appears, it should be destroyed and discarded immediately, or replanted in new growing medium and isolated. The way to prevent it is to keep the pot as clean as possible, avoid letting the pot come into direct contact with the ground, and maintain ventilation.

5. Gray mold: when flowering, the petals become water-soaked and discolored, and mold grows on them, indicating gray mold. The way to prevent it is not to let the petals get wet, and when the flower buds are still very small, spray them with a 1:2000 dilution of Benlate, and do not let the indoor temperature become too high.

The above diseases are all caused by fungal infection and can be controlled with fungicides such as thiophanate-methyl, chlorothalonil, and mancozeb.