In the autumn of that year, the plum orchard was well managed and plum yield was indispensable in the coming year.

Autumn is an important period for plum trees to restore their potential and accumulate nutrition. Scientific management can increase the nutrient reserve of plum trees, promote flower bud differentiation, and lay the foundation for high yield in the following year. The autumn management techniques of plum orchard are summarized as follows.

Postharvest management of plum

First, fertilizer and water management

1. Foliar fertilizer spraying: after plum harvest, 0.3-0.5% potassium dihydrogen phosphate was sprayed as soon as possible to improve the nutrient accumulation of plum trees, promote leaf assimilation and branch enrichment, and enhance the tree potential to survive the winter.

2. Base fertilizer: from late August to early October, base fertilizer is applied. The amount of fertilizer applied was 20-30kg of mature farm manure per plum tree in the early fruit stage, 30-50kg in the full fruit stage, 0.5-1.0kg urea and 1.5kg compound fertilizer (N ∶ P ∶ K = 15 ∶ 12 ∶ 15). The radial trench method was used to dig 7-9 radial trenches 30-40cm deep and about 40cm wide, sprinkled with mixed fertilizer, and then covered with a layer of soil. In this period, the root system of plum is at the peak of growth, the broken root is easy to heal, the decomposition time of fertilizer is sufficient, and the degree of mineralization is high. Some fertilizers can be absorbed and utilized by plum trees in the same year, promote leaf assimilation, manufacture and accumulate nutrients, and meet the needs of sprouting, flowering, fruit setting and growth of plum trees in the following year.

3. Irrigation: after fruit harvest, the first water should be irrigated in time, and the amount of irrigation depends on the soil moisture, so that the soil moisture is most beneficial to the growth and development of plum trees. When irrigating, a ditch with a depth of 20cm to 25cm is opened between the lines of Li Yuan, and the trench direction is preferably perpendicular to the waterway. Fill the ditch in time after irrigation. In the future, whether to irrigate or not is determined according to the soil moisture, and irrigate once before the soil is frozen, in order to enhance the photosynthesis of leaves, promote the accumulation of nutrients, and help the trees to survive the winter.

II. Soil ploughing

Generally in early September-early October combined with autumn application of base fertilizer for soil ploughing, ploughing depth of 20-40 cm. During this period, the aboveground parts of plum trees grew slowly, consumed less assimilation products, and began to reflux and accumulate. Therefore, ploughing the soil in this period coincides with the second or third growth peak of plum roots, and the wound is easy to heal; at the same time, it is easy to grow new roots, which is conducive to the absorption and synthesis of nutrients, increase tree accumulation, and is conducive to the growth and development of the following year. In addition, after ploughing in this period, after a long winter, it is beneficial to soil weathering and soil permeability. It can also eliminate underground pests and root weeds and root tillers.

III. Tree management

1. Clear the tree: pick off the disease and insect fruit left on the plum tree, concentrate and bury them deeply, and remove the root tillers from the root stem.

2. Qingtuan: remove weeds and litter from the ground, clear them out of the garden or burn them centrally, so as to reduce the number of overwintering diseases and insect sources.

IV. Shaping and pruning

Plums are harvested in combination with clear trees for heart picking and branch thinning. Attention should be paid to the selection of strong branches in suitable positions, thinning of weak, disease and insect pests, dense growth, sagging and overdense inner chamber, and coring of the remaining branches. Improve the ventilation and light transmission conditions of the trees, so as to enrich the branches and survive the winter, and lay a good foundation for winter shearing.

V. Disease and pest control

In order to protect leaves, reduce the source of disease and reduce the overwintering base of pests, 50% carbendazim 1000-fold solution, or methyl thiophanate 800-1000-fold solution, or 80% mancozeb 800-1000-fold solution, or 50% pyrethroid 800-fold solution can be sprayed on autumn trees; 2.5% enemy killing 3000-fold solution or 20% pyrethroid 3000-fold solution can be used for the control of plum borer.

VI. Overwintering protection

White the trunk before freezing the soil (adding an appropriate amount of fungicide to the whitening agent) to protect the plum tree safely through the winter.