Disease control of pearl bush

Leaf spot

disease

When leaf spot disease occurs, circular or irregular brown spots will appear on the leaves, and brown mold will grow sparsely on the spots on the back of the leaves.

Prevention and treatment methods

You can dilute it by spraying 500-800 times diluted solution of 50% thiophanate.

powdery mildew

disease

When white ice occurs, white or grayish white flour-like substances will appear on the leaves. In severe cases, the tender shoots will curl, the leaves will become uneven, and they will fall off early. The flowers are small and do not open, the petals are curled and dry.

Prevention and treatment methods

1. Remove diseased and damaged plants in late autumn and reduce the source of pathogens;

2. Pay attention to ventilation, reduce air humidity, increase light, add phosphorus and potassium fertilizers to enhance its resistance;

3. After the disease occurs, the affected parts should be cut off in time, or the diseased plants should be pulled out and burned;

4. Spray medicine. Spray an equal amount of 1% Bordeaux mixture during the dormant period. In the early stage of the disease, spray 800 times of 70 % thiophanate-methyl solution or 800-1000 times of 50% mancozeb solution.

Brown spot

disease

The brown spot disease of Pearl Bush mainly harms the leaves. In the early stage, brown circular to irregular shaped spots are scattered on the leaf surface. The edges are darker and clearly separated from the healthy tissue. In the later stage, sparse small dark brown to black brown spots appear on the back of the leaves, which are the fruiting bodies of the pathogen. The pathogen overwinters on the affected leaves in the form of mycelium or conidia, producing conidia the following year that are then spread by wind and rain to nearby plants. The disease is generally more likely to occur when ventilation is poor or when the trees are growing weakly.

Prevention and treatment methods

1. From July to September , you can spray 600 times the solution of 65% mancozeb wettable powder or 500 times the solution of 70% mancozeb wettable powder.

2. Strengthen management and improve disease resistance

3. In late autumn and early winter, the diseased leaves of mobile phones should be destroyed in batches to reduce the source of bacteria in the following year.