Symptoms and control of diseases and insect pests of cherry blossoms

Symptoms of perforated brown spot: the leaves appear purple-brown dots and gradually expand into a circle. Prevention and treatment of perforated brown spot: spray 3-5 Baumedu stone sulfur mixture before new shoot germination and spray 160 times Bordeaux solution when the disease occurs. Symptoms of leaf blight: the leaves appear yellow-green round spots, and then turn brown. Control method of leaf blight: spray Bordeaux solution before germination. Symptoms of root cancer: tumors occur at the site of the disease. Prevention and treatment of root cancer: the cancer can be removed with a knife saw.

1. Perforated brown spot

1. Symptoms

The main results are as follows: (1) the high incidence period of perforated brown spot of cherry blossoms is from May to June. The leaves will appear purple-brown spots at the onset of the disease, and gradually expand into a circle in the later stage.

(2) after drying and shrinking, the spot becomes a small hole, and the pathogen likes to overwintering on the diseased branches and leaves, and the suitable temperature for development is 25 ℃-28 ℃.

(3) it is generally spread by the wind, and it is often infected in the plum rain season, resulting in the weakening of the tree potential, and it is also easy to occur when the drainage is poor and the ventilation is poor.

2. Prevention and control methods

The main results are as follows: (1) in the process of cherry blossom growth, it is necessary to strengthen planting management, prune branches in time, cut off diseased shoots, clean up diseased leaves and burn them with fire in time, so as to create a sterile growth environment for plants.

(2) before the sprouting of the new shoots of cherry blossoms, 3-5 Baomedusite sulfur mixture can be sprayed. During the onset of the disease, 160times Bordeaux solution, or 1000-2000 times solution of 50% benzoate wettable powder can be sprayed.

2. Leaf blight

1. Symptoms

In summer, the leaves will appear yellow-green round spots, and then turn brown, scattered black particles, diseased leaves will die, but will not fall off.

2. Prevention and control methods

(1) when a disease occurs, the diseased leaves should be removed and burned with fire, and Bordeaux solution can be sprayed before germination.

(2) 65% of Dysen zinc wettable powder can be sprayed 500 times from May to June, and it is appropriate to spray once every 7-10 days and 2-3 times continuously.

3. Root cancer

1. Symptoms

The main results are as follows: (1) Root cancer mainly occurs at the base of the trunk and sometimes on the root neck and lateral roots.

(2) the tumor was milky white or flesh color in the early stage, and gradually became brown or dark brown in the later stage, which was round, rough, uneven and cracked.

(3) after infection, it will lead to poor root development, very few fine roots, slow growth of aboveground parts, weak tree potential, and serious leaf yellowing, early falling, and even the whole plant withered.

2. Prevention and control methods

(1) Cherry blossom seedlings infected with root cancer need to be burned with fire, soak in 1% copper sulfate for 5-10 minutes before planting, and then rinse with clean water for planting.

(2) when diseased plants are found, the cancer and other surrounding tissues can be removed with a knife saw.

(3) the soil around infected plants can also be disinfected with sulfur powder according to the dosage of 50-100 grams per square meter, and soil improvement can be carried out at the same time.