Key Management Techniques for Apricot Trees After Fruit Harvest

Apricot fruits ripen relatively early, and there is still a considerable period from harvest to dormancy. This period is an important stage for apricot trees to restore tree vigor and accumulate tree nutrients. Carrying out scientific management during this period can reduce the occurrence of pests and diseases, promote reasonable tree growth, promote further differentiation of flower buds, increase the number and quality of flower buds, and lay the foundation for a bumper harvest in the coming year. The specific management measures for apricot trees after harvest are summarized as follows:

I. Training and Pruning

1. After apricot fruit harvest, the tree body is still growing, so it is necessary to control vegetative growth, moderate tree vigor, and improve the light conditions inside the tree canopy. Pull and open the angle of vigorous branches to moderate tree vigor and promote flower formation; perform a second pinching of new shoots to promote branching and cultivate branch groups. The fruiting branches that are significantly weakened and drooping after fruiting should be properly retracted. For water sprouts emerging inside the canopy, measures such as pinching and twisting should be taken for those with growth space to control their vegetative growth; water sprouts without growth space should be promptly removed. At the same time, remove dead branches, split and broken branches, diseased and pest-infested branches, crossing branches, overlapping branches, and thin weak branches inside the canopy to reduce nutrient consumption of the tree, improve ventilation and light conditions of the tree, and facilitate the formation of high-quality flower buds.

2. For apricot orchards with excessive growth, spray paclobutrazol (PP333) or the growth regulator PBO to control tree vigor, so as to facilitate the formation of more flower buds.

II. Soil, Fertilizer, and Water Management

1. After apricot fruit harvest, combine with weed control and carry out one intertillage and soil loosening throughout the orchard, generally with an intertillage depth of about 10 cm. Before leaf fall, combine with basal fertilizer application and deep plow, with a depth of 30-40 cm being appropriate.

2. After apricot fruit harvest, fertilizer should be applied as early as possible, especially for trees with weaker vigor and those that bore more fruit that year; fertilizer should be applied promptly to compensate for nutrient consumption in the tree. Immediately after apricot fruit harvest, apply a quick-acting fertilizer once, applying 0.5 kg of urea per mature apricot tree, then water. Combine with pesticide spraying for foliar fertilizer application, spraying a mixed solution of 0.3% potassium dihydrogen phosphate and 0.2% urea to increase nutrient accumulation in the tree and improve the number and quality of flower buds. From late August to early October, apply basal fertilizer, mainly high-quality farmyard manure, mixed with a small amount of phosphorus and potassium fertilizer. Generally, 5-6 year old newly fruiting trees should be applied 30-50 kg of farmyard manure and 0.3-0.5 kg of superphosphate per tree; trees in full fruiting stage should be applied 70-100 kg of farmyard manure and 0.5-1.0 kg of superphosphate per tree, and watered immediately after application.

3. After apricot fruit harvest, irrigate for the first time in a timely manner so that soil moisture is most favorable for the growth and development of apricot trees. This irrigation can ensure normal flower bud differentiation and the growth, aging, and maturity of branches. If there is a lot of rain during this period, irrigation may be omitted. At the same time, attention should also be paid to drainage to prevent apricot trees from becoming diseased due to waterlogging, which would affect tree growth and development. Irrigate the freezing water well; where conditions permit, irrigate thoroughly once before freezing to ensure the apricot trees safely overwinter.

III. Pest and Disease Control

After apricot fruit harvest, apricot trees are often harmed by pests and diseases. According to actual conditions, spray pesticides in a timely manner to protect leaves and increase nutrient accumulation in the tree. Use 20% fenvalerate 2500-fold liquid spray to control aphids; use 40% methamidophos 1500-fold liquid, 40% dicofol emulsifiable concentrate 1500-2000-fold liquid, or 1000-fold pyridaben spray to control red spider mites. Spray 2-3 times with 2000-3000-fold fenpropathrin or fenpropathrin to control tent caterpillars and boat-shaped caterpillars. From August to October, spray Daconil M-45, thiophanate-methyl, or carbendazim liquid every 15 days or so to control apricot scab and bacterial shot hole disease.