Main diseases of camellia and their prevention and treatment

anthrax

This disease is one of the common diseases of camellia. It usually occurs on the leaves of seedlings between June and July , and the lesions mostly start from the leaf tips or leaf edges. When the disease first occurs, water-soaked green-brown spots appear on the edges of the leaves at the base, then expand into a layer of small black spots arranged in irregular large stripes, slowly spreading throughout the leaf, and finally causing the leaves to fall off.

Prevention and treatment methods :

1. Strengthen cultivation management, pay attention to the application of organic fertilizers and phosphorus and potassium fertilizers, improve the disease resistance of plants, and remove and burn diseased leaves in time.
2. After the spring shoots grow out, spray with 1% Bordeaux liquid to prevent infection by bacteria
3. In the early stage of the disease, spray with 65% mancozeb wettable powder and 600 times aqueous solution.

Sooty Disease

The disease that affects branches and leaves is most obvious on the leaves. In the early stage of the disease, small sooty mold spots will appear, then gradually expand and connect into pieces, and finally most of the plant will be covered with a sooty mold layer. After parasitizing, the pathogen not only absorbs nutrients from flowers, but also seriously affects the photosynthesis and respiration of the plants, and finally causes the plants to shed a large number of leaves.

Prevention and treatment methods:

1. Keep the plants well ventilated and light-permeable, and do not plant too densely.
2. Control the humidity, it should not be too high, to inhibit the growth of bacteria.
3. During the outbreak period, spray 0.3 degree Baume lime sulfur mixture once every 10-15 days , for a total of 3 sprays .
4. You can also spray 500 times diluted 50% thiophanate wettable powder , once every 7 to 10 days , and spray 3 times.

Root-knot nematode disease

It harms the roots of camellia, causing them to turn dark brown and the nodules to rot and burst. The taproot swells, new roots fail to grow, the above-ground plant stops growing, and eventually the entire plant dies.

Prevention and treatment methods:

1. Disinfect the culture soil before potting to kill any pathogenic insects that may be lurking.
2. After discovering the disease, immediately change the potting soil using sterilized culture soil.
3. Before repotting , you can expose the potting soil in the sun for 2-3 days before using it.
4. Spray pesticide to kill.

Moire leaf blight

It harms the young branches, leaves and buds of camellia. The spots on the leaves mostly occur at the leaf tips and edges. Initially, the spots are semicircular or irregular in shape, yellow-green in color, and then gradually turn brown. In the later stage, the spots are grayish white with dark brown edges. The diseased leaves become brittle in the later stage and fall off easily; the lesions on the tips are dark brown stripes, and in severe cases the branches die. The peak period of the disease is from May to August .