High temperature and high humidity season, high temperature, high humidity, 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
The topdressing of apple trees depends on the variety, the amount of fruit stored, and the previous fertilization. A phosphorus and potassium fertilizer, the main focus is potassium fertilizer, the amount of fertilization depends on the tree. The United States No. 8 and are among the early-maturing varieties, and in early July, the topdressing fertilizer, Red Fuji apples try to catch a fat from 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. It should be combined with rainfall for fertilization.
2. Foliar spray fertilizer
7 In August, the application of phosphorus, potassium, calcium, iron fertilizer, etc. on the foliar application 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. The commonly used fertilizers are superphosphate and dihydrogen phosphate. Potassium, potassium sulfate, plant 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
The rainy season orchard can not accumulate water for a long time, otherwise it will affect the soil permeability of the orchard and the root growth of the apple tree. After the rain, it should be drained in time to keep the soil moisture of the orchard relatively stable. After watering or raining, plan and remove the weeds in the garden.
Second, control tree potential
It is suitable for vegetative growth of apple trees in July and August, especially for young trees with early fruiting and less mature trees. Summer and autumn shoots tend to grow vigorously. If not regulated, it will affect flower bud differentiation, cause nutrient loss, tree shape disorder, and reduce fruit quality. Therefore, according to the age, tree potential, results, etc., appropriate measures should be taken. With regulation, the tree will grow robustly. For the long tree, it is usually sprayed 150 times of paclobutrazol in the upper and middle of July. For the prosperous young trees without fruit or fruit, the second trunk or main branch can be stripped in early 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.
Three, prevent apple sunburn
The affected 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, seriously affecting apple products. Value. July and August are the key periods to prevent sunburn.
1. Timely irrigation. When drought occurs, water should be given immediately to reduce the incidence of sunburn. /p>
2. Cover the tree tray. Before the onset of high temperature and drought, cover the tree tray with a layer of 20 cm thick straw, grass or wheat bran, which can protect the Lowering the ground temperature can prevent the occurrence of sunburn.
3. Covering the fruit surface. Covering the leaves of the leaves with large leaf area on the sunny side of the fruit prone to sunburn Hemp leaves or broadleaf grass, etc., can reduce direct sunlight, reduce the day
4. The crown sprays. When the sun sets or slant, the spray can be sprayed with water to reduce the sunburn.
Four pest control
1. Pest Control. In this period, red spiders, leaf miner, leaf roller moth, apple aphid and ringworm, anthracnose, early leaf disease and other pests and diseases are the focus of prevention and control. White spiders should be used according to local temperature, rainfall and occurrence; the leaf miner, leaf roller moth, and apple aphid should be used in the prevention of May and June, and should be used again in early July.
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. Protection before rain Fungicides, timely rain spray fungicide. In the production, a full set of bag cultivation should be carried out, which should focus on the prevention and treatment of early defoliation. Generally, it is sprayed once in mid-July, early August and late August; Red Fuji apple orchard is sprayed 3 times in June-August. Disabled in September to avoid affecting coloring.
Source Qixing Pesticide Wang Zhishun