How can dragon fruit be cultivated and managed for high efficiency?
1. Site establishment
Dragon fruit is relatively heat-tolerant and water-tolerant, and prefers warm, humid, sandy soil rich in organic matter. Before planting the seedlings, per mu, according to a 1.5 m × 2 m spacing, erect 100-110 cement square columns measuring 10 × 10 × 250 cm, with the cement columns inserted 50 cm into the soil, to support the dragon fruit branches as they climb. On both sides of each cement column, 5-10 cm from the top, drill one straight hole on each side, and run two perpendicular iron wires in a cross frame for the dragon fruit branches to climb and hang on. To prevent the branches from breaking due to excessive weight or being blown down by wind, a fixed used tire should be placed on the cross frame to support the branches. On two opposite sides of each cement column, dig one planting hole 10 cm deep and 20 cm long and wide, apply decomposed organic fertilizer mixed evenly with soil in the hole, plant 1 plant per hole, and plant 3-4 plants beside each cement column.
2. Planting
Dragon fruit can be planted in all four seasons. Plant 3-4 plants around each column, and let the dragon fruit plants grow upward along the column. Calculating 4 fruit seedlings planted per column, 667 sq m can hold 450 plants, which can greatly improve land utilization, increase the yield during the young stage, and recover the investment cost earlier. Do not plant too deep when planting (a depth of 3 cm is appropriate), and keep the soil moist in the early stage.
3. Water and fertilizer management
Dragon fruit is relatively drought-tolerant. In the early stage after planting, water once every 2-3 days, and afterward just keep the soil moist. The dragon fruit root system is relatively shallow, so fertilizer should be applied in small amounts and more frequently to prevent root burn and root rot. After the planted seedlings sprout, apply dilute human feces and urine in the planting hole about 10 cm from the seedling, about 1 kg per plant; afterward, at each sprouting, apply once human feces and urine supplemented with 0.3% urea and 0.1% potassium chloride, until the dragon fruit blooms. In the 1st year, apply fertilizer 6-8 times, mainly nitrogen fertilizer, combined with potassium, calcium, magnesium, phosphate fertilizers, etc. In winter, cover once with decomposed organic fertilizer or mushroom residue, about 10 kg per plant, to enhance the plant's heat preservation and cold resistance. After flowering and fruiting, apply fertilizer 3 times per year, namely the pre-flowering fertilizer in April, the fruit-strengthening fertilizer in August, and the overwintering fertilizer in December, mainly decomposed organic fertilizer and ternary compound fertilizer.
4. Field cultivation management
About 12-14 months after planting, dragon fruit begins to bloom and bear fruit. It can bloom 12-15 times per year, with the fruiting period from April to November. Fruits can be harvested 30-40 days after the flowers fade, and a single fruit generally weighs 500-1000 g. In the second year after planting, each column produces more than 20 fruits, and in the third year it enters the full fruiting stage. With a relatively high management level, the yield per 667 sq m can reach more than 2500 kg, with good early fruiting and high yield.
Apply thin fertilizer frequently: Because the fruit harvest period is long, heavy application of organic fertilizer is needed every year, and nitrogen, phosphorus, and potassium compound fertilizers should be applied in a balanced and long-term manner. During the flowering and fruiting period, supplement potassium and magnesium fertilizers to promote sugar accumulation in the fruit and improve quality. Keep the soil moist during the fruiting period, and cover the tree disk with grass or mushroom residue. In dry weather, irrigate once every 3-4 days.
Shape pruning: Before the branches climb to the top of the cement column, it is advisable to let them maintain single-branch growth. After they grow to the top of the column (1.3-1.4 m), the growing point should be pinched off to promote branching, and the branches should be allowed to droop naturally, accumulate nutrients, and bloom and bear fruit earlier. Well-growing dragon fruit has relatively high natural sprouting ability. Generally, each branch can send out 3-5 new shoots. To increase or decrease strong fruiting branches, during the annual vegetative growth period, each branch can retain 1-3 robustly growing branches depending on growth conditions; during the reproductive growth period, to ensure the nutritional requirements for fruit development, all newly sprouted branches should be thinned out.
Interplanting and artificial pollination: When planting red-fleshed dragon fruit, interplant about 10% white-fleshed dragon fruit. Mutual pollination between varieties can significantly increase the fruit-setting rate. In rainy weather, artificial pollination should be carried out. Pollination can be done in the evening when the flowers open or in the early morning before the flowers close, using a writing brush to directly apply pollen to the stigma of the female flower, so as to increase the fruit-setting rate.
Flower and fruit thinning: Dragon fruit has a long flowering period and strong flowering ability. It blooms from May to October, and each branch produces an average of 2.7 flower buds per flowering season. After normal pollination and fertilization, the faded flowers can be cut off by the ring-cutting method (retaining the stigma and the sepals below the ovary). When the young fruit reaches about 2 cm in transverse diameter, begin fruit thinning. Keep one young fruit per branch that is fully developed, bright green in color, undamaged and not deformed, and has a certain amount of growth space, and thin out the rest, so as to concentrate nutrients and promote fruit growth.
Fruit bagging: Before the fruit skin changes color, bag the fruit with old newspaper or kraft paper bags to keep the fruit skin evenly colored, and prevent pecking by birds, wasps, etc., as well as wind injury and direct sunlight exposure, thereby improving commercial value.
Timely harvest: The fruit growth period varies with production season, geographical location, and variety. Generally, it can be harvested about 45 days after flowering. Harvesting too late will not only cause fruit cracking, but also cause localized blackening of the fruit skin color, affecting commercial value. For fruit intended for long-distance transport or long storage, it is advisable to harvest before the fruit softens and the color darkens.