Since the demonstration and promotion of high-density cultivation techniques for the Early Dew Peach in Linzhang in 1995, significant economic benefits have been achieved. By adopting this technique, the yield of Early Dew Peaches can reach around 1000kg per 666.7 square meters within 15 months after planting, and in the third year, the yield can reach 2000-2500kg per 666.7 square meters with a good fruit rate of over 95%. Below are the cultivation techniques:
1. Selecting Strong Seedlings and Reasonable Dense Planting
Seedlings are planted in early spring after the soil thaws. One-year-old high-quality strong seedlings are selected and planted at a spacing of 0.8m x 2.5m. Before planting, a planting trench 0.5m wide and deep is dug, and 4000-5000kg of well-rotted organic fertilizer and 150kg of superphosphate per 666.7 square meters are applied. After planting, sufficient water is irrigated, and the seedlings are pruned immediately. The pruning height is 50-60cm, and the first bud at the top should be perpendicular to the row direction.
2. Strengthening Fertilization and Water Management
In the year of planting, fertilization and water management should be strengthened. Urea is applied to the soil in mid-May and mid-June, about 50g per plant each time. Potassium fertilizer is applied to the soil in early July, about 50g of potassium sulfate per plant. Watering should be done immediately after fertilization. Before July, water should be supplied every 15 days. For fruit-bearing trees, during the hardening period to the fruit enlargement period, 100-150g of urea and potassium sulfate are applied per plant, and 100g of urea per plant is applied after fruit picking. Base fertilizer is applied through trench application in September every year, using 5000-6000kg of well-rotted organic fertilizer and 100kg of specialized fruit tree fertilizer per 666.7 square meters. In addition, foliar spraying can be combined with pesticide application, applying 0.3% urea 2-3 times from May to June, and potassium dihydrogen phosphate 2-3 times after July. Watering should be done after fertilization or during drought. Avoid watering excessively before fruit ripening to prevent fruit cracking.
3. Scientific Pruning and Shaping
For dense planting peach trees, summer pruning is the main focus, supplemented by winter pruning, combining both seasons for annual pruning to achieve rapid shaping and early fruiting.
Winter pruning: Dense planting peach trees adopt the "Y" shape with two main branches. The tree height is 1.3m, and the trunk height is 30-40cm. Two main branches extend between the rows with an opening angle of 50-60 degrees. The main branches bear fruiting branches evenly. During winter pruning, keep branches with flower buds and remove those without. Remove upright, overly dense, and weak fruiting branches, leaving flat-growing, slanting, and moderate fruiting branches. Generally, retain medium-length fruiting branches of 15-40cm length, short-pruned to 4-8 flower buds. Ensure even distribution of fruiting branches, with a distance of 20cm between adjacent branches. For young fruit trees, retain 10,000-12,000 branches per 666.7 square meters, and for mature fruit trees, retain 16,000-18,000 branches per 666.7 square meters.
Summer pruning for young trees: In mid to late May of the planting year, when new shoots grow to 30cm, all new shoots except the top two vigorous ones are pinched back to 15-20cm. When the two vigorous shoots grow to 60cm in early June, pinch them back to 40cm. Other secondary shoots that grow to 30cm are also pinched back to 15-20cm. After July 10, no more pinching is done; instead, soften and open the angles of new shoots.
For fruit-bearing trees during summer pruning: After fruit setting, remove non-fruiting branches and double-bud branches. About 5-7 days before fruit maturity, remove vigorous upright branches and some leaves that block the fruit to promote fruit coloring. After fruit harvest, promptly shorten overly crossing vigorous branches between plants and rows, remove upright vigorous branches and hanging branches, and prune the current year's new shoots to promote the formation of new fruiting branches. Control tree height to about 1.5m, row spacing to about 50cm, and retain 25,000-30,000 new shoots per 666.7 square meters.
4. Flower and Fruit Management
During the red bud stage, remove poorly developed buds and buds without growth space. Thin fruits 4-5 weeks after flowering. Retain 4-6 fruits on long fruiting branches, 2-4 fruits on medium fruiting branches, maintaining a leaf-to-fruit ratio of 25-30:1. For young fruit trees, retain 50-60 fruits per plant, controlling yield to around 1000kg per 666.7 square meters. For mature fruit trees, retain 90-100 fruits per plant, controlling yield to around 2500kg per 666.7 square meters.
5. Chemical Control of Vigor
Around July 20, start spraying 15% paclobutrazol at 200-300 times dilution, once every 10-15 days, for a total of three times. This effectively moderates apical dominance, inhibits vegetative growth, and promotes flower bud differentiation. For fruit-bearing trees, when new shoots grow to about 100cm, spray 15% paclobutrazol at 150-200 times dilution to inhibit new shoot growth and improve fruit set.
6. Disease and Pest Control
Before peach tree budding, spray 3-5 Beaufort degrees of stone sulfur solution to control overwintering pathogens and insect eggs. After budding, spray 10% imidacloprid at 1500-2000 times dilution to control aphids. Focus on controlling red spiders and oriental fruit moths before and after wheat harvest, which can be controlled by spraying 20% abamectin at 2000 times (or acaricide at 2500-3000 times) plus 2000 times of cypermethrin. After July, focus on controlling shot hole disease and leaf rollers, which can be controlled by spraying 70% mancozeb at 800 times plus 1500 times of chlorbenzuron.