Six measures to promote Flower Bud differentiation of Fruit trees in Hot Summer

Summer is the period of flower bud differentiation of many kinds of fruit trees. the amount of nutrient accumulation and the quality of flower bud differentiation are closely related to the yield and quality of fruit trees in the following year. July and August are the high temperature and rainy season, which is suitable for the vegetative growth of fruit trees, especially in the early fruit stage, the summer and autumn shoots of young trees and adult trees with less fruit are easy to grow, if not regulated, it will cause nutrient loss, tree shape disorder, reduce fruit quality and affect flower bud differentiation. Therefore, during this period, in addition to normal soil, fertilizer, water management and pest control, some measures conducive to flower bud differentiation should be taken according to different varieties and different tree potential to control tree potential and ensure high and stable yield year after year.

I. timely fruit harvesting

The young or old and weak trees should be picked early according to the specific conditions of the tree potential so as to reduce the nutritional burden of the tree so as to restore the tree potential and promote the differentiation of flower buds. The method of picking fruit by stages should be adopted for the high-yield trees with good management and full-ripe cultivation, so as to prevent the weakness of the tree caused by the long time of keeping the fruit, which is not conducive to flower bud differentiation.

Second, protect the blade

Leaf photosynthesis is the nutritional guarantee of flower bud differentiation of fruit trees. Summer drought and the outbreak of red spiders are easy to cause early defoliation, so attention should be paid to prevention and control. Covering the tree plate with green manure, weeds and rice straw can effectively restrain soil water evaporation and reduce the surface temperature. Spray fungicides in time after heavy rain to prevent leaves from infecting bacteria and cause early defoliation.

Third, foliar topdressing

Nutrition must be replenished in time after fruit picking in order to restore tree potential, ensure sufficient nutrients for flower bud differentiation, improve flower bud quality and enhance winter resistance. Healthy trees are generally sprayed with 0.2% potassium dihydrogen phosphate solution or a mixture of 2%-0.3% calcium superphosphate and 0.3% urea; old and weak trees are sprayed with 0.3%-0.5% urea solution, once every 7 days and 4 times in a row.

IV. Proper water control

Apple, peach, plum, pear and other fruit trees begin to control water according to the weather conditions after applying liquid fertilizer, until the color of the leaves of the fruit trees becomes lighter, the leaves are slightly rolled or the topsoil is slightly cracked. If the drought is too serious, it is necessary to spray water on the leaf or sprinkle water on the border, and the water can be controlled for 20 to 30 days. For the trees with initial fruit and the strong trees with few fruit, the time of water control should be longer.

Fifth, cut the root and dry the root.

For mountain orchards with low topography and poor drainage or orchards with heavy soil, partial root cutting can be carried out in the early stage of flower bud differentiation, the roots of fruit trees with shallow root distribution can be dried, and the soil around the rhizome can be removed for 20-30 days. For fruit trees with flower bud differentiation period after October, pay attention to frost prevention, peel off the soil in the morning, and cover soil and grass in the afternoon.

VI. Regulating the tree potential

The trees were generally sprayed with 150 × 200 times of paclobutrazol or 200 times of PBO250 in the first ten days and the middle of July. The young trees with no fruit or few fruit can be peeled around the main branches at the beginning of July. At the same time, to do a good job in summer pruning, the key point is to remove the upright strong branches on the back, the long branches of the inner bore, the competitive branches and the useless branches that affect the light, and twist, soften or pull the slow branches, in order to control the vigorous growth, improve the ventilation and light transmission conditions, and promote the fruit development and flower bud formation.