Red-fleshed Honey Pomelo Cultivation Techniques and Management Points

The red-fleshed honey pomelo was bred by the Fruit Research Institute of the Fujian Academy of Agricultural Sciences from a bud mutation line found in a Guanxi honey pomelo orchard in Pinghe County. This pomelo has large fruit and thin peel, and its flesh is red, with anti-cancer and lipid-lowering effects. How does this pomelo grow? What are the red-fleshed honey pomelo cultivation techniques?

Red-fleshed Honey Pomelo Cultivation Techniques

1. This pomelo likes moist, loose, fertile soil; here we choose sandy loam with deep soil layers and good drainage as the planting soil. Its pH value should preferably be 5.5-6.5.

2. Pomelos grow vigorously and have large canopies; grafted trees enter full fruiting 6-7 years after planting. For mountain orchards, a spacing of 3×3 m may be used, planting 74 trees per mu; for flatland orchards, a spacing of 3×4 m may be used, planting 55 trees per mu.

3. Before planting, first dig a planting trench 0.8 m deep and 1 m wide, or a planting hole 0.8 m deep and 1 m wide and long; when digging, place topsoil and subsoil separately on each side. When backfilling, bury 25-50 kg of green manure, weeds, etc. at the bottom of each hole; when filling, put one layer of green manure and one layer of topsoil, and spread a total of 1 kg of lime powder layer by layer; in the middle of each hole, apply 15 kg of pig and cattle manure, 1.5 kg of cake fertilizer, and 0.5 kg of phosphate fertilizer, mix thoroughly with the subsoil, then mound the soil 20-30 cm above ground level.

4. Pomelos have a strong ability to set fruit, but cross-pollination can increase the fruit-setting rate and enlarge the fruit, so pollinator trees should be arranged when planting.

5. Planting is best done in early to mid-March. Before planting, cut off part of the branches and leaves of the nursery stock and any overly long main roots, retain as many fibrous roots as possible, and dip the roots in yellow mud slurry. When planting, dig a small hole in the center of the mound, place the nursery stock into the hole, let the fibrous roots spread naturally, then backfill soil, compact the soil, and the height of the buried soil must not cover the graft union. After planting, water thoroughly to settle the roots, and cover the tree basin with rice straw or other weeds. Within one month after planting, keep the soil near the roots moist; on sunny days, water about once every 3-5 days.

6. After the nursery stock is planted, cut it back 30-40 cm above the graft union to establish the trunk. After new shoots emerge, select and retain 3-4 new shoots that are strong, evenly distributed around the tree, and spaced from one another as the main branches, and remove the rest.

7. When the tip of each main branch continues to extend to about 40 cm, pinch and top it in time. On each main branch, select and retain 2-3 strong branches at suitable positions as secondary main branches. Proper spacing should be maintained between the trunk and secondary main branches so that the side branches that grow from them can receive sufficient light. Frequently remove water sprouts on the trunk and main branches that cross, overlap, or disrupt the tree shape, as well as shoots and buds in unsuitable positions.

8. Fertilization can begin after the fruit seedlings survive, one month after planting. In the first year, apply 2-3 times per month; use rotted manure water or biogas slurry diluted with 3 times water, or apply 0.3% urea or compound fertilizer as a drench; 5-10 jin per plant, gradually increasing the fertilizer concentration and amount according to plant growth. In the second year, fertilize about 15 days before the spring, summer, and autumn shoots emerge and when the leaves of each flush turn green; there are three shoot flushes in the whole year, so apply fertilizer six times, each time applying 5-10 kg of rotted human and animal manure per plant, plus 0.1 kg of urea or 0.1 kg of compound fertilizer. Apply in furrows.

9. In the first three years, young trees must complete hole expansion and soil improvement. That is, in December, dig a deep trench 50 cm deep, 40 cm wide, and 1 m long on both sides 1 m from the main trunk, then apply 20 kg of organic fertilizer + 1 kg of phosphate fertilizer, and fill green manure, leaves, weeds, dead branches, and fallen leaves into the trench, and sprinkle some lime; during the second hole expansion, the direction of the trench should be changed to the other two sides of the young tree.

10. Fruiting trees are generally fertilized at least 3 times per year. In early March, 10-15 days before sprouting, apply a bud-promoting fertilizer, mainly quick-acting nitrogen fertilizer with an appropriate amount of phosphorus and potassium fertilizer, to promote the emergence of a large number and good quality of spring shoots; generally apply 0.5 kg of compound fertilizer per plant. From June to August, during the fruit expansion period, apply a fruit-strengthening fertilizer; when there is a heavy fruit load and a large amount of fertilizer is needed, it can be applied in two applications in June and August, generally 0.5 kg each of urea and compound fertilizer per plant; when the fruit load is light, the fruit-strengthening fertilizer may be applied as appropriate or not applied, to prevent a vigorous flush of autumn shoots. In early November, apply a post-harvest fertilizer, generally 0.5 kg each of urea and compound fertilizer, 5 kg of cake fertilizer, and 50 kg of farmyard manure such as pen manure and garbage per plant.

In addition, appropriate amounts of urea and monopotassium phosphate can also be applied along with pesticide spraying for foliar topdressing, to promptly supplement the tree's needs for nitrogen, phosphorus, and potassium.

11. Fruiting trees are sprayed once with paclobutrazol from late October to early November; heavily bearing trees 6-10 years old are ring-cut once each in November and December. Flower thinning is carried out from mid-to-late February to early March, and flower branches or flower buds may be thinned. When buds emerge, focus on cutting away hidden leafless flower branches and weak flower branches inside the canopy; this is called thinning flower branches. About ten days after thinning flower branches, thin the remaining flower clusters again by removing the head and tail of each cluster and keeping the middle; generally, no more than 4 full flower buds are retained per flower cluster; this is called thinning flower buds. In April and early May, for bearing branches that carry 3 or more fruits, thin out the poorly developed diseased fruits, deformed fruits, densely clustered weak fruits, and small fruits, and retain normal fruits; this is called fruit thinning. Leave 1—2 strong fruits on each bearing branch, and in full fruiting period leave 100--200 fruits per pomelo tree.

12. When the fruit grows to a diameter of more than 10 cm, remove the leaves near the fruit, thoroughly eliminate pests and diseases on the entire pomelo tree before bagging, and then bag the fruit.

Red-fleshed honey pomelos generally begin trial fruiting 3 years after planting, and in full fruiting period can reach 2-3000 kg per mu.