How to manage greenhouse apricots in spring? Focus on management to promote development

For apricot trees in a winter-warm greenhouse, the fruit development period runs from mid-February to the end of April, and this period is divided into three main development stages. The first stage is the first rapid growth period of the apricot tree and the new shoot growth period, lasting 28-34 days; the second stage is the pit-hardening period, lasting 8-12 days; the third stage is the second rapid growth period of the apricot fruit and the new shoot growth period, lasting 20-30 days.

Management work for the first stage: after flowering, apply 0.5 kg of nitrogen fertilizer and 1 kg of phosphorus fertilizer per tree, and within two weeks after flowering spray 0.3% urea once every 7 days. After leaf expansion, spray Yibianjing or Yashijing at 3000-5000 times dilution. After flowering, promptly girdle the vigorous branches of vigorous trees, 3-5 cuts per branch, spaced 2-3 cm apart. Within two weeks after flowering, spray 3 times with fruit-setting agent, 0.1% boric acid, 25 ppm gibberellin plus 0.3% monopotassium phosphate, glucose and 300 times dilution anti-drop color-enhancing agent to increase the fruit-setting rate. Remove improperly positioned buds, and pinch the growing tips when new shoots reach 25 cm, with the timing at the end of February to early March. Thin out small fruits at the base of fruiting branches, deformed fruits, twin fruits, and fruits damaged by pests or disease. The maximum temperature inside the greenhouse should be 20°C-25°C, not lower than 7°C at night, the suitable temperature is 15°C-18°C, the relative humidity is less than 6%, the optimum ground temperature is 14°C-19°C; try to increase the carbon dioxide concentration inside the greenhouse and prevent the greenhouse temperature from fluctuating sharply.

In the second stage, two key points must be managed well: 1. Fruit setting. Leave one fruit on flower-bouquet fruiting branches, 1-2 fruits on short fruiting branches, 2-3 fruits on medium fruiting branches, and 4-6 fruits on long fruiting branches. 2. Temperature and humidity control. The maximum temperature should not exceed 28°C, the daily average temperature is best at 18°C-22°C, and the ground temperature at a depth of 10 cm should be controlled at 20°C-24°C.

In the third stage, three points must be managed well: 1. Fertilizer and water management. Spray once every 7-10 days with 0.2%-0.3% urea plus 0.2%-0.3% monopotassium phosphate, for 2-3 consecutive sprays. 2. Summer pruning. Pinch the growing tips when new shoots exceed 20 cm, pull branches to open the angle when scaffold branches grow to about 50 cm, promptly thin out vigorous shoots on the upper side and densely growing branches, open the light path, and carry out girdling and shoot twisting on some new shoots to promote flower bud differentiation and fruit coloring. 3. Environmental regulation. Keep the daytime temperature at 26°C-28°C, not exceeding 30°C, and the nighttime temperature at 10°C-25°C, so as to increase the day-night temperature difference; keep the humidity at 50%---60%, supplement carbon dioxide as much as possible, and pay attention to supplemental lighting; under the premise of not exceeding the maximum temperature, raise the greenhouse temperature as much as possible.