High temperature and high humidity in summer, climatic conditions are conducive to the spread of pests and diseases, is a critical period to prevent and control pests and diseases. At the same time, the new shoots of apple trees have also entered the second prolonged period, and the fruit development has entered a period of expansion. It is the management focus of this period to do a good job of tree regulation and promote the development of young fruits.

First, strengthen fertilizer management

1, reasonable topdressing

Whether the apple tree is topdressed or not depends on the variety, the amount of fruit stored, and the pre-fertilization situation. It can be applied once for phosphorus and potassium fertilizers, and the main focus is on potassium fertilizer. The amount of fertilizer applied depends on the tree. Mid-early maturing varieties such as the US No. 8 and Dora, topdressing in early July, red Fuji apples try to catch a fat in mid-July to mid-August. Because it is in the rainy season in July and August, if the weather is not dry, it may not be watered, and it should be combined with rainfall for fertilization.

2, foliar spray fertilizer

In July and August, the application of phosphorus, potassium, calcium and iron fertilizer on the foliar surface of the drug has an important role in increasing the sugar content of the fruit, promoting coloration, and alleviating the physiological diseases of the fruit. Commonly used fertilizers are superphosphate, potassium dihydrogen phosphate, potassium sulfate, ash, and ferrous sulfate. In production, potassium dihydrogen phosphate is used in combination with calcium chloride, and the concentration is preferably not more than 0.5% of the total salt concentration (total percentage of soluble fertilizer).

3, orchard drainage, weeding

Water can not be accumulated for a long time in the rainy season orchard, otherwise it will affect the soil permeability of the orchard and the root growth of apple trees. Water should be drained in time after rainfall to keep the soil moisture in the orchard relatively stable. After watering or raining, plan in time to remove weeds in the garden.

Second, regulation of the tree

In July and August, it is suitable for vegetative growth of apple trees, especially the summer and autumn shoots of mature trees with less primordial trees and less fruit hanging. If they are not regulated, they will affect flower bud differentiation, resulting in nutrient loss, tree-shaped disorder, and reduction. Fruit quality. Therefore, according to the age of the tree, the tree potential, the results, etc., appropriate measures should be taken to regulate and maintain the tree's robust growth. For the prosperous tree, the paclobutrazol is sprayed once every 150-200 times in the middle and the middle of July. For the prosperous young trees without fruit or fruit, the second trunk or main branch can be stripped at the beginning of July. At the same time, we must do a good job of summer pruning, the main point is to eliminate the erect stalks on the back, the long branches of the gangsters, the branches of the branches and the useless branches that affect the light, and twist the branches to achieve control. Improve the lighting conditions, promote fruit development and flower bud formation.

Third, prevention of apple sunburn

The victimized apple showed a loss of water on the sunny side, causing a reddish-brown near-round spot, and the spots gradually enlarged, forming a dark brown lesion with a pale yellow halo around it, which seriously affected the commercial value of the apple. July and August are the key periods to prevent sunburn.

1. Watering in time. In the case of drought, irrigation should be carried out immediately to reduce the incidence of sunburn.

2, tree tray coverage. Before the onset of high temperature and drought, a layer of 20 cm thick straw, grass or wheat bran on the tree tray can not only protect the ground, but also reduce the ground temperature, which can prevent the occurrence of sunburn.

3, the fruit cover. It can reduce the direct sunlight and reduce the incidence of sunburn in the sun-facing surface of the fruit that is prone to sunburn.

4. Paste the white paper. Apply a piece of white paper with emollient oil on the sun-facing surface of the fruit that is prone to sunburn, which can reflect sunlight and prevent sunburn.

5. Spray lime milk. Apply a layer of lime milk on the apple's sunny side, which can be reflective, anti-Japanese, and sterilized.

6. Apply amino acids in late July and August. At intervals of 15 days, it can not only increase drought resistance, but also reduce sunburn, promote fruit development, improve fruit quality, and make the next year's flower buds full.

7. Spray water in combination with spraying in the evening. When the sun goes down or when it is oblique, the canopy can be sprayed with water to reduce sunburn.

Fourth, pest control

1. Pest control. In this period, we have focused on pest control such as red spider, leaf miner, leaf roller moth, apple aphid and ring disease, anthracnose disease and early leaf disease. Control red and white spiders should be used according to local temperature, rainfall and occurrence. The commonly used agents are 1.8% avermectin EC 4000 times solution, 5% card dead emulsifiable concentrate 1000 times solution, 20% sudden death net suspension 2000 Double solution, 5% Nissole emulsifiable concentrate or 25% Benedict WP and Kruth emulsifiable concentrate 2000 times. The leaf miner and the leaf roller moth should be used for prevention and treatment in the first half of July based on the prevention in May and June. The commonly used agents are: 25% chlorpyrifos 3 suspension 1500 times solution, 1.8% avermectin emulsifier 5000 times. Liquid, 2.5% kungfu or cypermethrin 3000 times liquid; apple cotton aphid use 48% risper lotion 1000 times solution.

2. Disease prevention and treatment. July and August are another key period to prevent the risk of ring rot, anthracnose and early defoliation. In the use of drugs, the systemic bactericide and protective agent should be used interchangeably. Generally, the protective bactericide should be used before rain. Spray systemic fungicide. The production of a full set of bag cultivation should focus on the prevention of early defoliation, generally in the middle of July, early August and late August, the effective drug is: 1:2:200-240 Bordeaux mixture 50% carbendazim WP 800-1000 times solution, 70% thiophanate-methyl WP 1000 times solution, 70% or 80% mancozeb WP 600-800 times solution, 50% Because of 1000 times liquid, 10% polyoxymycin 1000 times liquid and the like. Bordeaux mixture and one of the above bactericides have a good effect, and the Bordeaux mixture is sprayed once every 20-25 days. The Red Fuji apple orchard was sprayed 3 times in June-August and was discontinued in September to avoid affecting coloring.