Cultivation techniques of plum trees are as follows:

1, rootstock and variety selection

Dwarf rootstock is selected, which has strong affinity with grafted varieties, and varieties with bright fruit color, high yield and slightly weak growth potential should be selected.

2. Pot soil preparation

Plum bonsai must contain enough fertility in limited pot soil to maintain the growth and fruit of plums. Generally, 4 parts of rotten leaves, 2 parts of rotten manure, 2 parts of broken bones and 4 parts of garden soil are mixed, and a small amount of calcium superphosphate and diammonium phosphate are properly mixed to increase soil fertility. Mix the basin soil fully and evenly, grind and sieve. The culture soil should be disinfected by spraying 1.5% formalin solution before use. When planting, let the roots stretch, soil up and compact, so as to achieve "three buries, two steps and one seedling raising", water the bottom and put it in the shade to slow down the seedlings.

3. Pour the soil into the basin.

The nutrients in the basin soil are gradually washed away by frequent watering. After 2 ~ 3 years, the soil fertility in the basin is insufficient and the physical structure becomes worse. It is necessary to pour pots in time and replenish new culture soil. Stop watering before pouring the basin, and let the soil shrink and separate from the basin wall, so as to pour out the basin soil. After the soil is inverted, cut off the old roots with a thickness of 2 to 3 cm around the pot soil, mix the organic fertilizer with the soil, and sieve to fill the bottom. Then bring the soil to the basin, add fertile soil around it, and water it 1 time.

4, plastic pruning

When pruning, moderately prune the annual branches to stimulate the germination of the branches and form a small crown tree with compact results. When selecting, retaining and cultivating the main lateral branches of young plum trees and completing the shaping task, it is necessary to balance the tree potential, maintain the master-slave relationship of the backbone branches at all levels, and appropriately prune the backbone branches that grow too fast. The trees that bear fruit for the first time are mainly short fruit branches and bouquets. After entering the fruit, according to the strength of its growth, leave 2 ~ 3 full buds at the base for further cutting. For long branches, it can be reduced to biennial branches, so that the middle and small branches in the whole crown are densely distributed.

5, wintering and cold protection

In the absence of freezing injury in winter, it is generally not appropriate to overwinter indoors, and let it overwinter naturally outdoors to improve the ability of trees to resist various natural disasters. In order to prevent freezing injury, you can choose to pour 1 time soil before freezing in sunny days, wrap the whole container with straw bags after the water seeps down, tie it tightly with ropes, or dig ditches and bury it in the leeward and sunny places.

6. Tian Tuan management

Enlarge the pit, improve the soil and apply heavy fertilizer deeply. Topdressing should be based on the principle of diligent application and thin application, and more application should be made at the tip stage. Fertilizer should be diluted first and then concentrated, and the dosage will increase with the expansion of trees. Pay attention to shaping and controlling branches to cultivate high-yield tree species. In summer, the long branches are mainly picked or cut short, and the long branches growing on the trunk and main branches are thinned. In winter, dead branches, diseased branches and drooping branches are mainly cut off.

7. Fertilizer and water management

After the planted seedlings survive, they are made into terraces with shallow ditches with a width of 20 cm and a depth of 5 cm. The terraces are used for drainage, irrigation and fertilization in summer. In the early growth stage, topdressing was applied once every 10 day, and ammonium bicarbonate and "Woye ion" potassium dihydrogen phosphate were applied. From germination stage to flowering stage, from young fruit stage to mature stage, 25 kilograms of urea, diammonium phosphate and potassium sulfate were applied per mu.

Fertilize the fruits underground in time during the vegetative growth period, with ammonium bicarbonate or urea of 0/50 kg per mu/kloc, and apply organic fertilizer in the border or tree tray in September every year, mainly with decomposed chicken manure and circulating fertilizer. Apply 3000 kg of high-quality coarse fertilizer, 30 kg of diammonium phosphate, 30 kg of potassium sulfate and 30 kg of urea per mu, and water once after each fertilization. In the whole production process, except watering after fertilization, water 1 ~2 times according to soil moisture, and intertillage and loosen the soil at any time after irrigation.