Prevention and control techniques of tea cake disease

Tea cake disease is one of the most important diseases of tea bud leaves, also known as leaf swelling disease, which is distributed in the mountain tea gardens of Sichuan, Yunnan, Guizhou, Hunan, Jiangxi, Fujian, Guangdong, Zhejiang, Anhui, Hubei, Guangxi, Taiwan and other provinces. In particular, the disease is most serious in the mountain tea gardens in Yunnan, Guizhou and Sichuan provinces. Let's take a look at the prevention and control techniques of tea cake disease.

Harmful symptoms of tea cake disease

The young leaves are light yellow or reddish brown translucent spots at first, and then gradually expand and sink into a yellowish brown or purplish red round spot with a diameter of 2 to 10 mm. The disease spot on the back of the leaf shows a cake-like process, with gray-white powder, and finally the spot becomes dark brown ulcerative, occasionally with a cake-like process on the front of the leaf, and the back of the leaf is sunken. After the petiole and tender shoots were infected, they swelled and twisted, and in severe cases, the new shoots above the diseased part withered and died. Flower buds and young fruits occasionally get sick.

The incidence regularity of tea cake disease

The pathogen overwintered or oversummer with mycelium in diseased leaves. It is a low temperature and high humidity disease. When the temperature is 18: 20 ℃ and the relative humidity is more than 85%, the overcast, rainy and humid condition is beneficial to the disease. Generally, the disease occurs seriously during the spring tea period from March to May and the autumn tea period from September to October. The disease was serious in hilly and flat tea gardens under rainy conditions, extensive management, weeds, improper fertilization, shaded tea gardens, foggy alpine and high wet concave tea gardens.

Prevention and control techniques of tea cake disease

1. Strengthen seedling quarantine to prevent the spread of tea cake pathogen through the transportation of tea seedlings.

2. Removing weeds and withered branches, pruning properly and promoting ventilation and light penetration can reduce the incidence of disease.

3. Increase the application of phosphorus and potassium fertilizer to improve the disease resistance of tea trees.

4. At the initial stage of the disease, 70% methyl thiophanate wettable powder 1000 / 1500 times or 75% chlorothalonil wettable powder 800 / 1000 times, with an interval of 7: 10 days, was sprayed 2 times for 3 times.

5. Spray 25% triadimefon (triadimefon) 3500 times liquid at the initial stage of the disease, the residual period is long, and you can spray it once during the onset period.

6. Non-picking tea gardens can also be sprayed with 0.6-0.7% lime half-volume Bordeaux solution, 0.2-0.5% copper sulfate solution or 12% oleic acid copper EC 600 times to protect tea trees.

7. if Bordeaux liquid is sprayed in the tea garden, it can be sprayed once before spring tea or after picking tea every season, and can not be picked until 20 days after spraying.