Detailed Explanation of Key Points for High-Quality and High-Yield Cultivation Techniques of Sweet Persimmon
Orchard establishment and planting. Sweet persimmon has no strict requirements for soil, but sandy soil with a pH value of 5.5-7.5 is optimal. An average annual temperature above 13°C is suitable. Most varieties of sweet persimmon have only female flowers but can set fruit parthenocarpically; however, planting pollinator varieties is more conducive to production. The main planted varieties should be selected for market suitability, large fruit size, attractive appearance, and flesh...
Sweet persimmon is a rare delicacy among persimmons introduced to China from Japan, with more than ten varieties including Xincilang, Fuyu, Izu, and Nishimura Wase. It has high nutritional and health value, is resistant to storage and transportation, has good marketability, and has excellent development prospects. The following introduces its high-quality and high-yield cultivation techniques:I. Orchard Establishment and Planting
Select sandy loam soil with deep soil layers and a pH value of 5.5-7.5; mountain land, flat land, and hilly land are all suitable. Dig trenches 100cm wide and 80cm deep, or large holes of 100cm x 100cm x 80cm, applying 50kg of decomposed farmyard manure, 5kg of superphosphate, and 0.3kg of potassium chloride per hole as base fertilizer. The best planting time for sweet persimmon is October to November. Generally, high-quality strong seedlings grafted onto Wild Persimmon No. 6 rootstock are preferred, planting 100-120 trees per 667 sq m, with pollinator varieties arranged at a ratio of 12:1 female to male trees.
II. Soil, Fertilizer, and Water Management
During the young tree stage, attention should be paid to loosening soil and removing weeds, with appropriate supplementary fertilization. In a 1-year-old planting orchard, apply the first fertilizer after spring shoots sprout, with 5-10g of urea and 5kg of human and livestock manure water per tree; thereafter, apply supplementary fertilizer 1-2 times per month, gradually increasing the amount. In the 2nd year, fertilize once each in March, May, August, and September. In the 3rd year, young trees begin to bear fruit, and potassium fertilizer and a small amount of boron fertilizer should be added. In years 4-5, sweet persimmon enters the high-yield period, and the "three fertilizations" should be applied well. First, pre-flowering fertilizer, applied in March-April, with 100g of urea, 100g of potassium sulfate, 50g of phosphate fertilizer, 5g of borax, and a small amount of multi-element micro-fertilizer per tree; second, fruit-strengthening fertilizer, applied in June-July, with 100g of urea, 150g of superphosphate, and 150g of potassium sulfate per tree; third, post-harvest fertilizer, applied in November-December, mainly with organic fertilizer and phosphate fertilizer, to provide sufficient nutrients for high yield the following year.
Persimmon roots are afraid of waterlogging; during the rainy season, attention should be paid to clearing ditches and drainage to strictly prevent waterlogging. However, July to September coincides with drought before fruit expansion, so watering for drought resistance should be done in a timely manner.
III. Training and Pruning
At planting, cut off the treetop at a height of 0.9-1m. During the dormant period in winter or early spring of the same year, select 3 branches in different directions and at different levels but with the same vertical and horizontal distance as main branches, with the first main branch 40-50cm above the ground. Cut back both the main branches and non-main branches on the trunk by 20% of their branch length. After 2 years of planting, in winter, cut off all non-main branches, cut back 20% of the current year's growth of main branches, and then cut off weak, crossing, and overlapping branches on side branches. Finally, at about 50cm from the trunk branching point, select a vigorous branch extending sideways as the first sub-main branch, and together with other retained side branches, cut back 20% of the current year's growth. After 3 years of planting, select and retain the second sub-main branch following the same method, forming a dwarfed natural open-center canopy.
Pruning of mature trees mainly involves cultivating strong fruiting mother branches on main branches and sub-main branches. In winter, shorten fruiting branches and some weak branches, and retract some overly long sub-main branches and old fruiting mother branches. In summer, thick and short fruiting mother branches can also be cultivated through twisting, bending, and girdling. Rotate and replace them each year, and promptly thin out overly dense branches, overlapping branches, weak branches, and water sprouts inside the canopy to ensure inner canopy ventilation.
IV. Flower and Fruit Management
1. Girdling during flowering: For trees with excessive vegetative growth, girdle the main branches and sub-main branches to a width of 0.2-0.4cm reaching the xylem during full bloom to improve fruit set rate.
2. Artificial pollination: Young male sweet persimmon trees have fewer male flowers; artificial pollination can increase fruit set rate by more than 35%.
3. Flower and fruit thinning: For weak trees and heavily flowering trees, thin out weak flowers and overly dense flowers during flowering, and thin out small fruits and deformed fruits during the young fruit stage. After the first physiological fruit drop in July, select and retain healthy young fruits at a ratio of 20-25 leaves per fruit, and remove excess fruits.
4. Bagging to protect fruit: Bagging can make the fruit smooth and uniform, prevent bird damage, sunburn, and fruit cracking, thereby increasing the rate of high-quality large fruits. Bagging is done after fruit thinning; spray a fungicide once before bagging, then use double-layer breathable paper bags. Remove bags 15 days before fruit maturity for coloring.
V. Pest and Disease Control
1. Disease control: The main diseases of sweet persimmon include anthracnose, angular leaf spot, and gray mold. Prevention should be the priority; disinfect seedlings before planting and do a good job of orchard sanitation in winter. Anthracnose and angular leaf spot can be controlled by spraying 70% thiophanate-methyl at 500 times dilution; gray mold can be controlled by spraying 50% duomeiqing at 1000 times dilution in the early stage of disease onset, and the effect is even better if 50% procymidone at 4500 times dilution is added.
2. Pest control: To control persimmon fruit borer, in early May, spread 0.5kg of 4% dimehypo powder on the ground under the canopy to kill overwintering larvae, and spray 20% fenvalerate EC at 3000 times dilution in the early larval stage; for slug moths, spray 2.5% deltamethrin at 3000 times dilution during the larval occurrence period; for scale insects, spray 40% methidathion at 1000 times dilution during the larval occurrence period.