How to manage apple trees in August

August is the flower bud differentiation period of apple trees and the fruit expansion period of middle and late ripening varieties. During this period, the photosynthesis was strong, and the photosynthetic accumulation was accelerated correspondingly. Except for the vigorous growth of new shoots, the growth of most new shoots stopped gradually from slow growth, a large number of absorbing roots occurred, and the absorption and utilization of water and nutrients also accelerated accordingly. Therefore, strengthening management in this period plays an important role in improving flower bud differentiation quality and fruit quality. The specific measures are as follows:

1. Trim. At the beginning of August, the vigorous branches of young trees were cut short to promote the secondary secondary shoots, which could form flower buds in the same year and achieve the goal of more flowers and early high yield. In addition, this period pruning also has obvious effect on branch group culture and crown control. It is appropriate to leave 3-5 leaves at the base of spring shoot in the cutting part. In the first ten days of August, for the big trees with too many auxiliary branches, part of the big branches can be removed, and the overgrown branches, erect branches and overgrown branches should also be thinned according to the space, so as to improve the ventilation and light transmission conditions of the trees and improve the quality of flower buds. At the beginning of August, the xylem of the new shoot was injured by opening the angle of the annual growing branch, which made the branch tissue damaged and drooping or horizontal, so as to restrain the top growth dominance, promote the secondary secondary shoot germination and increase the number of branches and leaves of young trees. The branches are relatively soft in late August, and the branches are not easy to sprout on the back after opening at the angle, which is a good time for backbone branches and large auxiliary branches to open their corners. Young trees should insist on pulling branches every year before they take shape, and do not pull them into a bow before they are opened at an angle, so as to avoid strong branches on their backs.

two。 Soil, fertilizer and water management. In the first ten days of August, 0.3% urea + 0.5% potassium dihydrogen phosphate solution was sprayed on the leaves of the spray to promote the ripening of new shoots and improve the cold resistance. Spraying again after 10 days can improve the coloring and sugar content of the fruit. The garden slices with bitter pox disease were sprayed with 0.5%-1% calcium chloride for 3 times at the beginning of August, mainly spraying the fruit, which can increase the pulp hardness and improve the storage resistance. Autumn shoot growth gradually stopped in the middle of August. Topdressing compound fertilizer could prevent premature senescence of leaves, promote tree nutrition accumulation, restore tree potential, be beneficial to flower bud differentiation and fruit expansion, and increase fruit setting rate and shoot growth in the next year. In this period, watering combined with topdressing plays a good role in increasing yield, coloring and quality. After watering or rain, ploughing and weeding in time, the young garden can be ploughed deeply, with a depth of about 20cm to 30cm, in order to thoroughly remove weeds and promote root growth.

3. Fruit management. The bagged fruits of medium-ripe varieties began to be bagged from the middle to late August. The double-layer bag should first remove the outer bag, and then go to the inner bag after 3-5 days; the single-layer bag will tear open the bottom of the paper bag, leave the residual bag on the fruit, and remove it after 3-5 days. Pay attention to choosing the time of day when the temperature difference between the inside and outside of the bag is small. After removing the bag, the leaves were picked, the fruit was turned, and the reflective film was applied to promote the overall coloring of the fruit. The marshal varieties which are easy to drop fruit before harvest are sprayed with 3040 mg / kg naphthalene acetic acid in mid-August and one month and half a month before harvest respectively to prevent fruit drop before harvest.

4. Pest control. Continue to investigate and treat rot. Alternately use 1 ∶ 2 ∶ 200 times Bordeaux solution, 50% prohydantoin wettable powder 1000x 1500 times solution, 50% mancozeb wettable powder 500x solution to control anthracnose, ring disease, leaf spot and other diseases, and remove the diseased fruit in time. 2000-fold solution of 25% thiazuron 3 was used to control Lepidoptera pests such as Spodoptera litura and Spodoptera litura. In late August, tree trunks were tied with grass to trap red spiders and other pests to survive the winter, and then thawed and burned before thawing the following year, so as to reduce the population density. When the fruit is unbagged and examined for the presence of Kangshi pink scale larvae, the tree should be sprayed with 52.25% Nongdile 1500 × 2000 liquid to control its damage.

Song Suzhi and Chai Quanxi, Vocational Education Center, Gaocheng District, Shijiazhuang City