How to Grow Sweet Persimmons for High Yield and High Quality
Sweet persimmon is a rare delicacy among persimmons introduced into China from Japan, with more than ten varieties such as Xinciro, Fuyu, Izu, and Nishimura Wase. It has high nutritional and health value, stores and transports well, has good marketability, and offers excellent development prospects. Its high-quality, high-yield cultivation techniques are described below:
1. Orchard Establishment and Planting
Choose sandy loam with deep soil and a pH of 5.5--7.5; mountain land, flat land, and hilly land are all suitable. Dig a trench 100cm wide and 80cm deep, or large holes of 100cmx100cmx80cm, and apply 50kg of decomposed barnyard manure per hole, plus 5kg of superphosphate and 0.3kg of potassium chloride as base fertilizer. The best planting time for sweet persimmon is October--November. Generally, it is best to use fine, strong seedlings grafted onto wild persimmon No. 6 rootstock, planting 100--120 plants per 667 sq m, and configuring pollinator varieties at a female-to-male ratio of 12:1.
2. Soil, Fertilizer, and Water Management
During the young tree stage, pay attention to loosening the soil and removing weeds, and apply appropriate topdressing. In a 1-year-old planting orchard, apply the first fertilizer after the spring shoots sprout, with 5--10g of urea and 5kg of human and livestock manure water per plant; thereafter topdress 1--2 times per month, gradually increasing the amount. In the 2nd year, fertilizing once each in March, May, August, and September is sufficient. In the 3rd year, young trees begin to bear fruit, so potassium fertilizer and a small amount of boron fertilizer should be added. In years 4--5, sweet persimmon enters the full production period, and the “three fertilizers” must 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 microfertilizer per plant; second, fruit-swelling fertilizer, applied in June--July, with 100g of urea, 150g of superphosphate, and 150g of potassium sulfate per plant; third, post-harvest fertilizer, applied in November--December, mainly organic fertilizer and phosphate fertilizer, to provide sufficient nutrients for high yield the following year.
Persimmon roots are afraid of waterlogging, so during the rainy season pay attention to clearing ditches and draining water, and strictly prevent water accumulation. Since July--September, before the fruit expands, is a dry period, watering and drought resistance work should be done in time.
3. Training and Pruning
At planting, cut off the treetop at a height of 0.9--1m. In the dormant period of the same winter or early spring, select 3 branches in different directions and at different levels but with the same vertical and horizontal distance as the main branches, with the first main branch 40--50cm above the ground. Cut back both the main branches and the non-main branches on the trunk by 20% of their shoot length. Two years after planting, in winter cut off all non-main branches, cut back 20% of the current year's growth of the main branches, and then cut off the thin, weak, crossing, and overlapping branches on the side branches. Finally, at about 50cm from the branching point on the main trunk, select a strong branch extending sideways as the first secondary main branch, and together with the other retained side branches cut back 20% of the current year's growth. Three years after planting, select and retain the second secondary main branch according to the above method, so as to form a dwarfed natural open-center canopy.
Pruning of adult trees is mainly to cultivate strong fruiting mother branches on the main branches and secondary main branches. In winter, shorten the fruiting branches and some thin, weak branches, and retract some overly long secondary main branches and old fruiting mother branches. In summer, thick and short fruiting mother branches can also be cultivated through twisting branches, pulling branches, and girdling. Replace them in rotation every year, and promptly thin out overly dense branches, overlapping branches, thin and weak branches, and water sprouts inside the canopy to ensure good light penetration inside the canopy.
4. Flower and Fruit Management
1. Girdling at flowering stage: For trees with excessively vigorous vegetative growth, girdle the main branches and secondary main branches during full bloom to a width of 0.2--0.4cm and deep to the xylem, to increase the fruit-setting rate.
2. Artificial pollination: Young sweet persimmon male plants have fewer male flowers, and artificial pollination can increase the fruit-setting 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 at the flowering stage, and thin out small fruit and deformed fruit at the young fruit stage. After the first physiological fruit drop in July, select and retain strong young fruit at a ratio of 20--25 leaves to one fruit, and remove excess fruit.
4. Bagging to protect fruit: Bagging can make the fruit smooth and uniform, prevent bird damage, sunscald, and fruit cracking, thereby increasing the proportion of high-quality large fruit. Bagging is carried out after fruit thinning. Spray a fungicide once before bagging, then bag with double-layer breathable paper bags. Remove the bags 15 days before the fruit ripens for coloring.
5. 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 main approach: disinfect seedlings well before planting, and do a good job of orchard cleaning in winter. For anthracnose and angular leaf spot, spray 70% thiophanate-methyl at 500 times dilution for control; for gray mold, spray 50% duomeiqing at 1000 times dilution at the early stage of the disease, and if 50% procymidone at 4500 times dilution is added, the effect is even better.
2. Insect pest control: To control the persimmon fruit borer, in early May scatter 0.5kg of 4% dimethoate-trichlorfon powder on the ground under the canopy to kill overwintering larvae, and spray 20% fenvalerate emulsifiable concentrate at 3000 times dilution at 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% superside at 1000 times dilution during the larval occurrence period.