How to control apple leaf spot disease? What are the preventive measures for powdery mildew? How to deal with apple tree rot?

Many farmers have a lot of experience in growing apples. China, as a country with high apple production, its apple cultivation techniques have also been recognized by the world. The launch of various apple varieties gives consumers more choices. So do you know anything about pest control in apple cultivation? Tuliu.com summarizes the prevention and control methods of apple spot leaf disease, apple powdery mildew and apple tree rot.

1. Control methods of apple leaf spot disease

1. Strict quarantine. Try not to introduce seedlings and scions from the disease area.

2. Clear the garden strictly. Autumn and winter carefully sweep away fallen leaves, cut off diseased branches, and concentrate on burning and burying. Spray 40% Fumei arsenic wettable powder 100 times before germination to eradicate the source of the disease.

3. Forecast. It can be monitored by spore traps. The method is to apply Vaseline with glass slides, hang the rope on the branch, 1.3 to 1.5 meters above the ground, hang 5 pieces near the four corners and the center of the plot, change once every 3 days, and take off and examine under the microscope. On the fourth day of the spore peak day, the millet grain size of the disease spot can be seen; on the seventh day after the peak, the first disease spot was found in the field, that is, it should be treated with medicine.

4. Chemical control. Focus on the protection of early leaves, based on prevention. The first dose of medicine should be in mid-May, and the second time should be sprayed 7 days later. Spray the medicine again in June, July and mid-August. Pay attention to the alternate use of multiple drugs.

Drug use plan

Leaf spot disease is serious in spring (from late April to late May) and autumn (from the end of June to mid-late July), and brown spot can occur from June to August, and the peak period is from July to August. Practice has proved that the prevention of primary infection through spraying is very important to control the disease in the later stage.

A. is generally adopted. In previous years, orchards with mild disease were diluted and sprayed with 200-300 solution of "Liang-Guo-an"; B. In previous years, orchards with mild disease were sprayed with 300 times liquid of "Liang, Guo, an" and 600 times of (Wo-Fengsu). From 7-10 days after anthesis to fruit ripening period (November), it must be sprayed once every 10-15 days to protect leaves and prevent infection.

Focus on the protection of spring shoots and leaves, according to the rainfall, spray from 10 to 15 days after falling flowers, spraying 3 to 5 times, each time at intervals of 15 to 20 days. The agents with better effects are: 50% prohydantoin wettable powder or 10% polyoxymycin 1000: 1500 times liquid, 70% aluminum triethylphosphonate and mancozeb mixture 800 times liquid, or 70% mancozeb wettable powder 500 times liquid. There are other special fungicides for the prevention and treatment of leaf spot disease: 1000 times of polyoxymycin, 1000 times of 50% prohydantoin, 4000 times of 10 times, 0.15% of Wuningmycin, 2000 times of 12.5% uniconazole and 1000 times of tebuconazole. Any of the above agents mixed with fertilizer mixture [Guobao] can get twice the result with half the effort.

Preventive measures against apple powdery mildew

1. Select apple seedlings that are disease-resistant, insect-resistant, high-yield and disease-free.

2. Select fields with high dryness and convenient drainage and irrigation as orchards.

3. When the nursery is sick, spray 50% sulfur suspension 200 times continuously at the initial stage of the disease, or 0.2-0.3 Baumedushi sulfur mixture for 2-3 times (about 7 days apart)

4. the budding seedlings should be cut 15-20 days before germination, disinfect the wound with 1% copper sulfate, and then apply Bordeaux solution to protect it. When planting seedlings, the grafting interface should be flat with the ground, the planting depth should be avoided and enough water should be irrigated so as to shorten the slow seedling time.

5. Before sprouting, fruit trees were sprayed with a mixture of diseases and insect pests, combined with the control of other diseases and pests, spraying 40% Fumei arsenic 100 times or Baume 3-5 degree stone sulfur mixture plus 0.3% pentachlorophenol sodium mixture to protect the trunk.

6. when the young fruit is formed, cover it with a paper bag coated with perilla oil.

Spray 1.58% phenylmercuric nitrate (PMN) when 50% of the leaves fall in autumn.

III. Prevention and control of apple tree rot

1. Reasonable pruning, thinning of flowers and fruits. Scientific pruning techniques are adopted to form reasonable plant types and promote the robust growth of fruit trees; at the same time, flower and fruit thinning techniques are adopted to avoid the formation of years and enhance the disease resistance of trees. (2) strengthen the prevention and control of other diseases and insect pests of fruit trees.

Strengthen cultivation management: enhance the tree potential and improve the disease resistance of the tree.

2. Applying 50kg N: P: K is 7 ∶ 3 ∶ 7 compound fertilizer for each fruit tree, and applying soil miscellaneous fertilizer, circle manure and green manure.

3. Thinning flowers and fruits to put an end to the phenomenon of big and small years.

4. Apply white to prevent frost injury. In areas prone to sunburn, the trunk is painted white after defoliation in early winter.

5. reduce the wound, prohibit the pruning in the severe winter, and apply paint to the wound.

6. Prevent spring drought and stagnant water, make the water content of trees normal, reduce the anti-expansion ability of bacteria, and speed up wound healing.