Plum trees are not dioecious, but the results will be affected by growth age and weather changes. Generally speaking, the result will be three years later. If it is a cultivation technical probl:] Reasons for low yield of plum trees and countermeasures: plum trees have strong adaptability and early effect; Plum fruit has high nutritional value, bright color and rich fragrance. Plus plum fruit is listed in advance, and the supply of fresh fruit is sufficient. So Li is more and more in this area. With the continuous improvement of people&;s living standards, the demand for Li has also increased year by year. At present, Li has low production in some production fields becaus: 1. Extensive management, no fertilization or less fertilization can not meet the needs of its growth. It causes serious falling flowers and fruits and low yield per unit area. 2. Improper pruning, too many or too few branches. 3. Single variety, poor pollination and fertilization. 4. Li Zaohua. North China generally blooms from late March to late April and from late April to early May in Northeast China. At this time, the temperature is low, the pollen tube elongation is slow, and abortion is easy, which is not conducive to pollination and fertilization. 5. Yi Lee was affected by late frost in flowering and young fruit period, which led to a large number of flowers and fruits falling, seriously affecting the yield. 6. The scale insects are seriously harmful and the trees are fragile. 2. Count: 1. Strengthen the management of fertilizer and water in orchards and enhanc: can be applied with base fertilizer in September, mainly farmyard manure. At the same time, add 1% urea. It is beneficial to restore the vitality of trees and increase the accumulation of storage nutrients. (2) Pay attention to the combination of nitrog: in the growing season. Topdressing and irrigation before flowering. One kilogram of urea will be added to each adult tree, and the amount of urea in young trees will be reduced. After fertilization, it should be watered in time to meet the demand for water and fertilizer in flowering period, which can make seeds germinate neatly, flowers full, pollinate and fertilize for a long time and improve fruit setting rate. During fruit setting, combined with pest control, 0.3% to 0.5% urea was added to the liquid medicine. Can effectively alleviate the situation of insufficient nutrition supply. Top dressing during flower bud differentiation, around June 20th, combined with pest control, adding 0.3-0.5% urea and 0.3% potassium dihydrogen phosphate into the liquid medicine. Conducive to flower bud differentiation and fruit expansion. Topdressing after harvest; Foliar spraying fertilizer is mainly carried out through phosphorus and potassium fertilizer. The crown can be sprayed with 0.3% potassium diammonium phosphate and 0.3% urea. It is beneficial to enrich branches. 2. Determine the appropriate amount of branch: in winter. The yield of plum is related to the number of branches, branches and fruiting branches, which affects the yield. Most branches are preserved, nutrients are dispersed, and landscape conditions are deteriorating. Branchlets in the inner chamber are easy to die, and the produced parts are easy to move outward, thus reducing the yield. Determining the appropriate number of branches is an important guarantee for high yield, stable yield and high quality. The average yield per plum tree is 100-150kg,The number of bouquets of fruit branches can reach 4000-6000. Large fruit varieties can reduce the number of branches. 3. Pay attention to the configuration of pollinated varieties or artificially assisted powder feeding, release bees at flowering stage and improve the cross-pollination rate of plum, which can obviously reduce fruit drop and incr: (1) Choose varieties with late flowering. (2) Thawing and irrigation with topdressing in early spring to reduce the ground temperature. (3) Spraying lime milk 50 times on branches before germination can mak:, in addition to delaying the flowering period to prevent freezing injury in early spring, according to the weather forecast, the orchard can be irrigated or sprayed with water before frost occurs. 6. Strengthen the control of :, a scale insect in plum orchards all over the country. Scale insects are very common, which will cause plum trees to grow very little, even very weak, and often die. This has seriously affected the number of Li Shu&;s families. In winter, brush the insects on the trees with a hard brush, or cut off the extra branches, or gently scrape off the skin with a scraper. The insecticide can be sprayed in the concentrated incubation period in May and early June respectively to control nymphs. Commonly us: enemies or 50% cartap.