Common diseases of crape myrtle and their prevention and control methods

Powdery mildew on crape myrtle

symptom

Powdery mildew of crape myrtle usually occurs on young shoots and flower buds. In spring and summer, infected leaves grow twisted and covered with a layer of white powder. Circular spots will appear on the leaves, and in severe cases they may become connected into one. The affected leaves will fall off prematurely due to the lesions.

Prevention and treatment methods

Remove diseased leaves of potted crape myrtle promptly and move it to a well-ventilated and well-lit place.

Once spots are found on the leaves, spray the pesticide in time. You can choose 500 times diluted mancozeb wettable powder, 1000 times diluted thiophanate methyl, Bordeaux mixture, etc. Spray it once every 10 days. The condition will improve after 3 to 4 sprayings.

Crape myrtle sooty mold

symptom

Sooty mold mainly harms the leaves and branches of crape myrtle. A layer of black mold appears on the petiole, affecting the photosynthesis of the plant. Sooty mold disease is mainly caused by insect pests or fungal infections, and is more serious in hot and rainy weather.

Prevention and treatment methods

Improve ventilation and reduce humidity in the air. Don't water it without any reason, keep the soil in the pot relatively dry.

Make good preparations for insect prevention. After May, the temperature will gradually rise. Spray the flower protector once a month to avoid the appearance of aphids or scale insects.

Prune diseased leaves and spray with fungicide. For black leaves, rinse them with clean water. If they appear to be wilted or yellow, they need to be cut off immediately and then sprayed with fungicides to prevent the spread of the disease.