A detailed breakdown of the latest growing conditions for jackfruit
Jackfruit, also known as wood jackfruit, tree jackfruit, large tree jackfruit, etc., is an evergreen tree of the genus Artocarpus in the Moraceae family. It originated in India and Southeast Asia and was introduced to China nearly a thousand years ago. It usually grows 10-20 m tall, with dark brown bark, leathery elliptical leaves, and monoecious flowers. When the fruit ripens, its skin turns yellowish brown and is covered with wart-like protrusions and coarse hairs. Its cultivation value is very high. Now let us take a look at the growing conditions for jackfruit!
Growing conditions for jackfruit
Jackfruit prefers hot, humid lowland environments and a warm, humid tropical climate. It is not cold-tolerant. The annual average temperature of the planting site is required to be greater than 21°C, the average temperature of the coldest month greater than 13°C, and the absolute minimum temperature greater than 0°C. A ground surface temperature of 0°C makes it prone to frost damage. It is not strict about soil and can grow normally in deep, fertile, loose, well-drained acidic soil as well as in slightly alkaline clay or sandy loam. Cultivation is best in low hilly land or flat land below 600 m in elevation.
Propagation methods for jackfruit
1. Seed propagation: During the main ripening period of jackfruit, select dry-pulp fruit that is fully mature, normally developed, and free of pests and diseases for seed selection. Wash them clean with water, then spread them flat on a sand bed for germination, cover the sand bed with fine sand 1-2 cm deep, then cover with 1 layer of rice straw, and water 1-2 times daily. After about 1 week, they will gradually sprout and take root. When the seedlings grow 1-2 true leaves, they can be transplanted to separate beds.
2. Bud grafting propagation: Jackfruit seedlings can be bud grafted once they grow to more than 1 cm, using the patch bud grafting method. Select one-year-old, sun-facing, mature branches from superior varieties as scions. The scions should be kept moist during storage, and it is best to graft immediately after collecting them. In Hainan, bud grafting can be done throughout the year, but the survival rate is higher during the rainy season and tree growth season from April to October. At this time, the rootstock and scions peel easily, and they survive easily after grafting.
Planting management of jackfruit
1. Timely planting: Jackfruit can be planted all year round, but spring planting (March to April) and autumn planting (September to November) are best. When planting, break up the soil in the planting hole finely, straighten and arrange the seedling roots, then press in fine soil layer by layer, keeping the root crown level with the ground. After planting, water thoroughly immediately to settle the roots, and cover the tree base with plastic film.
2. Reasonable fertilization: Fertilization of young jackfruit trees is aimed at promoting shoot growth and rapidly forming a canopy. In addition to applying organic fertilizer as base fertilizer in winter, apply quick-acting fertilizer before each new shoot flush to promote and strengthen the shoots. For fruiting trees, after harvest, apply a heavy dose of organic fertilizer together with a small amount of quick-acting fertilizer to restore tree vigor, improve leaf function, and promote flower bud differentiation. In early spring, before sprouting and flower cluster emergence, apply quick-acting fertilizer to promote new shoot growth and flower cluster development. When the fruit rapidly enlarges, apply fruit-strengthening fertilizer again to promote fruit development.
3. Water management: Jackfruit requires sufficient water, especially during the flowering period and fruit development period. If there is a long drought, small fruits may drop or development may stagnate, resulting in small, deformed fruit, small bulbs, thin flesh, and poor quality. Therefore, if it is too dry during the flowering and fruiting periods, irrigation should be carried out. However, the rainy season is prone to waterlogging, so drainage work should be done well to prevent root rot from standing water.
4. Shaping and pruning: The fruiting parts of jackfruit are on the trunk, main branches, and small lateral branches. When the trunk height reaches 1 m, cut back the trunk to stimulate branching. Cross branches, dense branches, and overlapping branches should be removed as necessary. Generally, cultivate 3-4 primary branches, with a canopy height of 3.5 m, to form a reasonable tree structure. Pruning of fruiting trees is mainly done in winter, mainly to remove dead branches, weak branches, overly dense branches, residual fruiting branches, and male flower branches.
5. Fruit thinning and fruit retention: Jackfruit is thinned in March to April each year, preferably retaining 3-5 fruits per sq m of canopy, with even and reasonable distribution. The principle of fruit thinning is to remove overly dense fruit and deformed fruit. During the young fruit stage, spray 1 time every 15 days with insecticide + fungicide + foliar fertilizer. When the fruit is basically set, spray 1 time every 30 days with insecticide + fungicide to prevent pest and disease damage and promote fruit expansion.
6. Pest and disease control: Among jackfruit pests, longhorn beetles and beetles are common and serious, damaging branches and trunks, causing gummosis, branch dieback, tree decline, trunk hollowing, and even rot and death. Adults can be captured and killed, eggs scraped off, or chlorpyrifos 600-fold solution used to coat the trunk and injected into insect holes. Main diseases include leaf spot, sooty mold, and soft rot of flowers and fruits, which can be controlled with 1000-fold carbendazim or 1500-fold chlorothalonil.
7. Timely harvesting: The fruit ripening period of jackfruit is relatively concentrated from June to August, but it varies earlier or later depending on regional climate. Where temperatures are high, flowering is early and ripening is earlier. Where temperatures are low, flowering is late and ripening is later. Because the flowering period of the same plant is long and ripening occurs successively, harvesting should be done in stages to ensure quality, increase yield, and also help restore tree vigor. The fruit can be harvested when the hexagonal wart-like protrusions on the rind are rounded and prominent, the shape is plump, the rind feels slightly soft to the touch, and a fragrant aroma can be smelled. After harvesting, it can be eaten after ripening for 2-3 days.