A detailed guide to green jujube cultivation techniques, all the key methods are here

First, select seedlings, and plant them in spring and autumn at a reasonable planting density. When planting, it is best to use nutritional-bag jujube seedlings with well-preserved root systems. Fertilize and water reasonably. After planting, pay attention to pruning branches, and at the same time do a good job of pest and disease control.

1. Seedling selection

Green jujube is an improved southern wild jujube (Ziziphus mauritiana), and there are many cultivated varieties. After several years of variety comparison trials, it is considered that varieties such as Gaolang No. 1 and No. 2 are suitable for popularized cultivation in the middle and south subtropical regions.

Green jujube trees have vigorous growth. When selecting seedlings, attention should be paid to choosing seedlings with pure variety, robust and disease-free growth, plump buds, stem diameter of more than 0.4 cm, height of more than 40 cm, and well-developed roots.

2. Reasonable planting

1. Planting time

Green jujube is a subtropical evergreen fruit tree, and planting can be carried out in spring and autumn. For orchards with irrigation conditions, planting in autumn from October to December can result in fresh jujube yields the following year that are significantly higher than those of jujube trees planted in spring in March of the same year.

2. Planting density

The row spacing should preferably be 4 m × 4 m or 4 m × 5 m, that is, 40 or 33 plants per 667 sq m (1 mu). 3. The width and depth of the planting hole are both 0.8-1 m. The planting hole should be filled with 80 kg of decomposed and sifted farmyard manure plus 2-3 kg of Puquan organic fertilizer, and during the filling process it should be thoroughly mixed with the soil.

3. Planting method

When planting, it is best to use nutritional-bag jujube seedlings with well-preserved root systems. During planting, first gently remove the fruit seedling's nutritional bag, then trim the main root at the bottom of the bag flat and plant it with soil in the planting hole. Afterward, water thoroughly to settle the roots, and once the seedling begins to sprout, start applying Puquan organic fertilizer at 0.5 kg per plant.

3. Main cultivation and management techniques

(1) Fertilization techniques

1. Fertilization for newly planted trees: Because newly planted green jujube trees have underdeveloped root systems, they both need nutrient supply and are prone to root damage. Therefore, fertilization should adhere to the principle of light fertilizer applied frequently, that is, small meals more often. Generally, for every 1-2 times of shoot growth, fertilizer should be applied once, with Puquan organic fertilizer at 1 kg per plant.

① Base fertilizer: apply Puquan organic fertilizer at 2-3 kg per plant, using hole application, then cover with soil and water.

② Topdressing: apply Puquan organic fertilizer at 1.5-2.5 kg per plant, using hole application, then cover with soil and water.

2. Fertilization for perennial trees

① Base fertilizer. After retractive pruning from February to March, dig a ring ditch at the drip line of each tree's canopy and apply Puquan organic fertilizer deeply at 1-2 kg per plant. Fertilization at this time cuts roots and helps regulate the balance of the root-to-shoot ratio, and promotes shoot growth.

② Shoot-strengthening fertilizer. One month after retractive pruning, new shoots begin to sprout, that is, from April to August new shoots are continuously produced. Therefore, in mid-March, apply Puquan organic fertilizer at 1-2 kg per plant, using hole application, then cover with soil and water.

③ Flower-promoting fertilizer: flowering and fruit set occur from September to October, so the flower-promoting fertilizer is required to be applied in mid-June with Puquan organic fertilizer at 1-2 kg per plant, using hole application, then cover with soil and water.

④ Fruit-strengthening fertilizer: apply in November with Puquan organic fertilizer at 2-3 kg per plant, using hole application, then cover with soil and water.

(2) Water management

1. Shoot growth period (April to July): to cultivate the canopy, irrigate promptly during drought, otherwise tree vigor will not be strong.

2. Flowering and fruit-setting period (September to October): irrigation should be paused to promote the plant's transition from vegetative growth to reproductive growth.

3. Fruit development period (November to December): the plant again needs a large amount of water. If this period suddenly alternates between dry and wet, it can easily lead to severe fruit drop.

4. Harvest period (December): avoid heavy irrigation, otherwise quality will decline.

4. Pruning

Green jujube grows quickly, bears a large fruit load, and has soft branches, so after planting, bamboo frames and the like should be set up for support. The main pruning work is to promptly select and retain 5-6 main branches after planting, and remove or prune the remaining buds and branches. Once entering the fruiting stage, when the fruit diameter reaches 2 cm, the relatively thick new shoots must be pinched. Note that after each harvest of the last batch of fruit, pruning should be done 30-50 cm above the graft union to cultivate strong branches for the following year.

5. Pest and disease control

Green jujube is a relatively disease-resistant jujube tree. The main disease is powdery mildew. Its symptoms are white fuzzy material growing on the trunk and leaves. It can be treated by spraying a 3000-5000 times dilution of triadimefon emulsion. At the same time, green jujube is also prone to showing nutrient deficiency symptoms, such as magnesium deficiency with band-like chlorosis on the leaf surface, which can be treated by spraying the foliage three times with a 300-500 times dilution of magnesium chloride; chlorosis of old leaves with scorched edges indicates potassium and phosphorus deficiency, which can be treated by spraying the foliage with a 300-500 times dilution of monopotassium phosphate; irregular yellowing and drying of leaves in the middle part of the tree indicates manganese deficiency, which can be treated by soil application of a 400 times dilution of borax plus a 500 times dilution of manganese chloride.

The main insect pests of green jujube include scarab beetles, inchworms, and others. During the larval stage, a 800 times dilution of trichlorfon can be sprayed; at the fourth to fifth instar, a 500 times dilution of fenitrothion can be sprayed. To reduce pesticide residues, omethoate and organophosphorus pesticides should be used less.