Thinning apple trees
After the apple enters the period of full fruit, let it be a natural result, and there will often be large and small year results. In old years, due to the large number of fruits and large tree loads, despite the higher yields, the fruit quality was poor. This not only reduces economic efficiency, but also often results in weakening of the tree and even premature aging. A large number of flu were caused until the tree died. Therefore, apple management must strictly control the load of the tree and implement thinning and thinning of fruit in order to obtain high-yield, stable production, high-quality, and high-yielding cultivation effects. Reasonable load has a direct relationship with the strength of tree vigor and the level of cultivation and management. The tree potential is weak, the water and fertilizer are insufficient, the photosynthetic capacity of the leaves is reduced, and the corresponding load is smaller. Instead, increase the load appropriately. According to foreign reports, apple needs 200 square centimeters for every 100 grams of fruit. Then, for every 25 grams of fruit weight added, a corresponding increase in leaf area of ​​75 square centimeters is required. If the output of the following year is guaranteed, the leaf area nutrition factor should be increased by 200 square centimeters. That is to say, a fruit (calculated by 175 grams) under normal circumstances requires a total area of ​​625 square centimeters of leaf area, so as to ensure the output of the current year, but not to appear in the following year. In order to achieve a reasonable load on the tree and overcome the phenomenon of big and small years, it is necessary to carry out sparsely fruit thinning and fruit thinning. Sparse flowering is generally carried out in areas where the climatic conditions are good and stable during the flowering period and there is no danger of late frost. The time spent on flowering is generally from the early to the end of the flowering season. According to the size of the tree flower, according to the appropriate fruit load and the rational distribution of the fruit, Caixia removes the method of "single-to-one" or "several-to-several" inflorescences. Then, if possible, remove some of the edges. flower. Practice has proved that the sparse flower has important effects on saving tree nutrients, increasing single fruit weight, and increasing fruit setting rate. The fruit thinning generally begins 7 days after flowering and is required to be completed within 30 days. There are many methods to determine the fruit thinning standard. The following are introduced: 1, according to leaf fruit than fruit thinning Dwarf anvil, short-stemmed apple, strong leaf assimilation ability, leaf to fruit ratio of 25 to 30:1; ordinary Joe anvil common apple large fruit, such as the Marshal leaf to fruit ratio of 35 to 40:1. 2, according to the number of top buds fruit The Marshal is a species of four top buds to stay a fruit, singing 15,000 per 1000 square meters; land five apical buds to retain a fruit, leaving about 12,000 fruit per 1000 square meters; Guo Guoguang, red fruit type Jade wait until the variety, the number of three top buds a fruit, 19500 ~ 25500 fruit per 1000 square meters. Fuji, Jonagold, shrub strength with the Marshal Department of varieties. 3, dry weeks determine the amount of fruit left Wang Jingyan of the Institute of Fruit Research of the Chinese Academy of Agricultural Sciences, based on a large number of investigations, proposed to use the Zhou method to determine the fruit-retaining standard of apple trees. 4, according to the distance of fruit Large fruit, weak trees, leaving fruit distance, and vice versa. The General Marshal Department, Fuji and other large fruits to stay away from 20 to 25 cm. When thinning the fruit, care should be taken to remove those small, deformed and diseased fruit, leaving a large bract close (or upright) fruit. The inside and the lower part of the canopy should be sparsely reserved, and the upper part and the outer part should be sparsely left. The key to thinning and thinning fruits is to grasp "early". With conditions permitting, it is better to do it sooner rather than later. In areas where the climate is stable during the flowering period, it can be spent on the premise of ensuring that the flowering period is not affected by freezing and freezing. However, in varieties and orchards with unstable climate and vulnerable to low temperature during the flowering period, the method of “preserving and adjusting later†should be adopted, that is, the flowers should be preserved first, and then the fruits should be shredded as early as possible. 5. Chemical thinning and fruit thinning (1) The use of agents, concentration and period of use: 1000 to 2000 ppm of carbaryl, 10 to 20 ppm of naphthalene acetate, 150 to 200 ppm of naphthalene acetate, and 7 to 10 ppm of naphthaleneacetic acid; (90%) 1000 times, both sprayed two weeks after full bloom. Guoguang sprayed the drug 10 days after it was sprayed with 2000ppm of Cevaine. Ethylene 300ppm plus naphthalene acetic acid 20ppm sprayed 10 days after blooming. Trichlorfon (90%) 800 times plus naphthalene acetic acid 15~20ppm 10 days after flowering and once spent lime sulfur spent two days after flowering, all have good results. Marshal is a general (natural type) natural fruit set-up rate is not high, the size is not obvious. However, in some orchards, the fruit setting rate is also high, and the size is obvious. It is better to use Cevaine 1500~2000ppm for fruit thinning 14 days after flowering. (2) Preparation of pharmaceuticals: The concentration of chemical agents must be accurately formulated before chemical agents are removed. Otherwise, it will cause sparse or excessive sparing and cause losses to production. The concentration of ppm is commonly used in the formulation of pharmaceuticals, and the concentration of ppm is the concentration of pure dose. 1ppm concentration, that is one million water plus one pure drug. All kinds of pesticides are calibrated with pure amounts, such as 25% carbaryl WP, ie 1 kg containing 0.25 kg pure carbaryl. Dongguan City Risen Medical Products Co., Ltd. , https://www.risenppe.com