Ten measures to increase fruit set rate in apricots in greenhouses
1. Variety configuration. Select self-cultivation rate and high rate of complete flower, wide range of adaptability to environmental conditions such as temperature, humidity, light, etc., have strong resistance to low temperature, low light, moisture resistance, such as gold sun, kaite apricot, shed king, etc. . The pollination requirements are the same as the flowering period of the main cultivars, the pollination affinity is strong, and the pollen amount is large. It is best to plant multiple varieties and pollinate each other. The ratio of pollinated varieties to main cultivated varieties is generally 1:3 to 4. 2. Improve the nutritional level of the tree. Through rational land and fertilizer management, plastic pruning, pest and disease control, tree potential chemical regulation, and sparse fruit thinning and other means, roots and trees, improve the tree's nutritional level, increase the number and quality of flower buds, reduce degraded flowers. 3. Top dressing before and after flowering. The main nitrogen fertilizer can be applied alternately with soil fertilizer and foliar spray fertilizer. The timely application of available nitrogen fertilizer before flowering can make up for lack of nutrition, ensure flowering and flowering, improve pollination, and increase fruit setting rate. After flowering, quick-acting nitrogen fertilizer and appropriate amount of phosphorus and potassium fertilizer can make up for the consumption of nutrients in flowering, increase fruit setting rate, promote young fruit development and prevent physiological fruit drop. Fertilizer before flowering: Each tree applies 0.5 kg of urea and 100-200 g of trees. Post-harvest fertilizer: 100 grams of potassium sulfate compound fertilizer is applied to each plant, and soybeans can also be crushed and decomposed, and 0.5-1 kg of each plant can be topdressed. Foliar spray fertilizer: spray 1 to 2 times before flowering 1% to 3% of urea, after spraying 14 days after the formation of 0.2% to 0.3% urea spray, promote leaf color, every 10 to 15 days 1 time. 4. Scientifically determine the time for the tarpaulin. According to the low temperature demand of the species and the weather conditions of the year, it is prudent to determine the time for the shed, and do not unload the sheds in advance. If the required amount of cold is not satisfied, and the natural dormancy is not finished, that is, the production of the shed is reduced, the fruit setting rate is significantly reduced, and there is no yield. Most apricot varieties in normal years can be shed in the first half of January, but if there is an atmospheric abnormality in the warm winter phenomenon, the time should be postponed. 5. Bees pollinate. 1 to 2 days before flowering, the beehives are moved into a greenhouse to train the bees. Place a flat plate at the entrance of the beehive. Put a little sugar and water in the pan. The depth of water does not exceed 0.4 cm. Generally 1/15 hectares (1 mu) below the greenhouse, put a box of bees (1.2 million or more) per shed. 6. Wall bee pollination. Wall bees can resist low temperatures and can normally be pollinated when the temperature reaches 12°C. At the same time, the visits are fast and the pollination ability is strong. Wall bee pollination is best for the bees, and its pollination efficiency is 80 times that of bees. Generally, every 50-100 hectares of bees can be placed on every 1/15 hectare. 7. Artificial pollination. The best pollination time was 0.5 hours after flowering. Artificial pollination had the best effect within 4 hours after flowering, and it could not exceed 48 hours after flowering at the latest. The use of liquid dusting can be carried out when a large number of flowers bloom during flowering period. The best pollination effect is between 9 a.m. and 10 a.m. in a day. The use of artificial points can be started from the beginning of apricot blossoms, and multiple pollinations are performed according to the inconsistent characteristics of the single flowering period. 8. Temperature regulation. Temperature regulation is the key to improving fruit set. (1) Before the shed. Covering the mulching film 15 to 20 days before the shed increases the temperature slowly. (2) buckle shed to flowering period. Flower buds need to be further developed and enriched after the shed is warmed up. Therefore, after the shed is warmed up, it should be carried out gradually to ensure that it takes about 28 days from the shed to flowering; in addition, attention should be paid to night heat preservation to prevent freezing damage. The temperature rise from the shed to the bud before flowering can be divided into the following stages: The first stage: Pull up about 2/5 grasshoppers, and keep the temperature at 8-12°C for 5-6 days. The second stage: Pull up about 2/3 grasshoppers and keep the temperature at 10-15°C for 3 to 4 days. The third stage: Pull up 4/5 grasshoppers, keep the temperature of 10~20°C for 2~3 days. The fourth stage: pull up most grasshoppers, the greenhouse temperature is controlled during the day 20 ~ 25 °C, 7 ~ 10 °C at night until flowering. (3) Flowering period. The suitable temperature for apricot pollen germination is 18～21°C, the nighttime temperature can not be lower than 6°C, the temperature is too high, the flowering period is shortened, the stamen development is blocked, the stigma is atrophic and dry, the viscosity is decreased, the effective pollination time is shortened, the number of pollen grains is reduced, germination The rate of decline, the rate of fruit set. During the flowering period, the temperature should be maintained at 16 to 18°C, the maximum temperature should not exceed 22°C, and the minimum temperature at night should not be lower than 6°C, so as to facilitate the extension of the flowering period and increase the fruit setting rate. 9. Flower cut. After the apricot tree is cut, it is necessary to carry out a ring cut on the flowering branches. Generally, 3 to 5 branches are cut for each branch, and the distance between the rings is 2 to 3 cm. Cut 1 to 2 weeks to heal. The circumcised flowers only apply to Wangshu. 10. Spray growth regulators and trace fertilizers. Full flowering foliar spray of 0.2% to 0.3% borax, or 0.3% borax + 0.3% urea, or 0.2% urea, 50 mg/litre gibberellin, 100 mg/l cytokinin, 0.2% manganese sulfate, and 0.5 % sodium molybdate. Sprinkling 10 to 50 mg/L gibberellin 5 to 10 days after flowering can promote fruit setting. In the flowering period, 7 days after flowering and 14 days after flowering, spraying 40 mg/L greenhouse for 3 consecutive times was very effective in improving fruit setting rate. 14 days after flowering, gibberellin and its mixture, anti-drop color enhancer, and anti-dropping agent, etc., can increase the fruit setting rate by 10% to 90%. Flowering and young fruit spray 2 times 6 MG / L rare earth can improve the fruit setting rate and fruit quality.