First, the tree is strong and weak, and the fruit trees in spring sprout to the peak of spring shoots. The construction of all new organs, such as rooting, flowering, leaf spreading, young fruit development and spring shoot growth, mainly depends on the nutrition stored in the previous year. If there are too many flowers, the growth of new shoots and roots will be too weak due to insufficient storage nutrition, such as "small leaves, more fruits, less new roots and short new shoots".
For the "New Year" tree, subtraction (reducing branches and flowers) is used on the ground in spring, and addition (skillfully flushing fertilizer and water) is used underground, which is beneficial to strong trees and excellent fruits. From the perspective of saving trees and strengthening trees, thinning fruits is not as good as thinning flowers, thinning flowers is not as good as thinning buds, and thinning buds is not as good as thinning buds; According to the survey, in recent years, the leaves of fruit trees sprayed with amino acids before flowering have obviously become larger, greener and thicker.
Second, in the early stage of pest control, the temperature of fruit trees gradually increased after germination, and various overwintering latent pests and diseases such as scale insects, apple powdery mildew, mold heart disease, pear psylla, dichotomous aphid, scab and peach aphid began to bite. At this point, they have no ability to reproduce and spread. As long as the medicine is cleaned twice and bagged three times in time after flowering, the nest can be destroyed and rooted, and preventive measures can be taken to lay the foundation for ensuring "good leaves, good fruits and good branches" throughout the year.
Third, the flowering period of fruit trees in the north can be said to be "nine disasters in ten years". In fact, the disastrous weather that affects the flowering period of fruit trees is not only low temperature (≤ 15℃) and frost (≤-2.8℃), but also bad climatic environment such as rain, strong wind, sand blowing and high temperature (≥25℃), which will cause the flowers of fruit trees not to crack normally, insects not to pollinate normally, pistils not to fertilize normally, some will reduce production, and some will.
The "guarantee" of flowering management of fruit trees is the premise of high yield, and "sparse" is the guarantee of excellent fruit. In order to ensure the yield, it is very important to spray "0.004% brassinolide 3000 times or whole fruit 1000 times+Yi Hui 1500 times+oligosaccharide boron 2000 times" and artificially pollinate to keep flowers and yield. Because "protecting flowers is to repair wealth, and fruit is to string money."
Fourth, the annual output of fruit trees in summer has been formed. After the middle and short branches are capped, the fruit begins to expand rapidly when it enters the flower bud differentiation stage. The assimilation function of vegetative organs is the strongest, and the consumption of trees is mainly based on the utilization of organic nutrition in that year.
To overcome the "big and small years", ventilation and light transmission (there should be flower spots under the tree) are the premise, fertilization and strengthening the tree (mainly organic fertilizer with chemical fertilizer formula) are the foundation, and the key is to limit production (about 654.38+0.5 million fruit per mu in the full fruit period), and the guarantee is to control the prosperity and protect the leaves (80% of the new shoots stop growing at the end of May).
Verb (abbreviation of verb) Nutrient accumulation Autumn is the storage period of organic nutrition. Except a small part of the assimilates in leaves are used for fruit and flower bud differentiation, most of them begin to flow back to the phloem, pith and root of branches 1 ~ 1.5 months before defoliation, until the defoliation is over. The amount of nutrients stored in late autumn has a significant impact on the smooth completion of the process of germination, flowering, leaf spreading, shoot shooting and fruit setting of fruit trees in winter and next spring. To increase the accumulation of tree potential, spraying chemicals to protect leaves is the premise, spraying fertilizer to raise leaves is the guarantee, and fertilization in early autumn is the key.
Sixth, adjust the tree potential and grasp the winter scissors. During dormancy, the activity of trees is relatively weak, and the storage nutrition of aboveground branches is relatively less, which is suitable for winter cutting.
The primary task of fruit tree pruning in winter is to adjust the ventilation and light transmission conditions of the tree body. The standards for groups and individuals to use light efficiently are: bright rows can let cars pass (row width 1 m or more), and trees should not be too high for easy operation (the height of trees should be controlled at about 3 meters). The second is to adjust the tree potential, prune the flourishing trees according to the potential, and transform the flourishing branches through pulling; Weak trees are pruned together, and weak branches and weak buds are sparse.