Experience Sharing on Dwarfing and Close Planting Cultivation of Jujube Trees

Dwarfing and close planting cultivation of jujube trees means transforming the large, widely spaced arbor into a short, compact plant resembling a small shrub; it is a new type of cultivation model. This model helps save land resources, facilitates intensive cultivation, and supports modern management.

Jujube trees have a short juvenile phase and the characteristics of early flowering and early fruiting. The farming proverb “peaches take three years, apricots four, pears five, but jujube trees pay back the same year” scientifically illustrates that jujube trees have the habit of early flowering, early fruiting and early high yield. The formation of early yield in jujube trees is, within a certain range, positively correlated with the amount of branches and leaves per unit area and the level of soil coverage. When the branch volume per mu is 0.75-20,000, the spur volume per mu is 30,000-60,000, and the branch and leaf coverage rate is 70-85%, the yield per mu can reach 1200-1500 kg. Therefore, adopting dwarfing and close planting, enlarging the population structure, increasing the amount of branches and leaves, and reaching the high-yield target earlier can lay a good foundation for early high yield in dwarfed and closely planted jujube orchards.

In dwarfed and closely planted jujube trees, the tree body is short and compact, and the fruiting positions are mostly at 60-120 cm, so the carbon dioxide in the space near the ground where temperatures are high can be more fully utilized, light is abundant, light energy use efficiency is high, and the photosynthetic capacity of leaves is strong. In the upper part of the tree body in the jujube orchard, the amount of light received accounts for 75-80% of full sunlight, while the middle part receives 30-35% of full sunlight. Therefore, the upper, middle and lower leaves of the tree body can all receive sufficient sunlight; the leaves grow larger and thicker, the palisade tissue is well developed, the chlorophyll content is high, and more organic nutrients are produced. As a result, more photosynthetic products accumulate in the jujube tree and less are consumed, which promotes a strong capacity for three-dimensional fruiting, more fruit, larger jujube fruits, bright fruit color, high nutrient content and high sugar content. Therefore, dwarfed and closely planted jujube orchards begin fruiting early, have high and stable yields, and high yield per unit area.

In dwarfed and closely planted jujube orchards, the planting density is generally 440 trees per mu (1×1.5 m), or 330 trees per mu (1×2 m). For jujube-grain or jujube-vegetable intercropping, the density is 220 trees per mu (1.5×2 m), or 110 trees per mu (2×3 m).

For jujube cultivation, a north-south row orientation is best, because plants in north-south rows receive side light evenly, the angle of strong midday light entering is large, fruit coloring is good, the ripening period is early, and fruit quality is excellent.

For land preparation in a dwarfed and closely planted jujube orchard, trenching and hanging slots is preferable: dig long trenches 60×60 cm, keep topsoil and subsoil separate and placed apart, first mix the topsoil evenly with farmyard manure and an appropriate amount of phosphate fertilizer and backfill it into the trench, then mix the subsoil evenly with fertilizer as well and backfill it into the upper layer of the trench. When planting jujube seedlings, they must not be planted too deep or too shallow; the original seedling depth is appropriate, and after planting, enough water must be given to settle the roots. During the sprouting and growth period of jujube trees, pests and diseases must be controlled promptly, and soil, fertilizer and water management must be strengthened. In the same year, the jujube trees bloom and bear fruit, with a small yield. In the second year, the yield per mu is about 200-300 kg; in the third year, the yield per mu can reach about 600-800 kg; in the fourth year, they enter the full fruiting period, and the yield per mu can reach about 1200-1500 kg. In the fifth year, stumping should be carried out alternately row by row once. Stumping is done in mid-to-late March each year, and the stumping position is 10-15 cm above the grafting point. The stumping saw cut should be smoothed with a knife and coated with white paint to prevent nutrient evaporation. After the stumped jujube trees sprout, the upper buds should be removed, leaving 1-2 buds at the lower part. When the sprouted shoots grow to a height of more than 20 cm, stakes should be set up and tied firmly to prevent wind breakage. ?In the same year the jujube tree is stumped, in the same year it sprouts and grows rapidly and thickly, and in the same year it blooms and bears fruit. At the same time, the excessive vigorous growth of the tree body in the jujube orchard must be controlled, with timely bud removal, pinching, branch twisting, branch breaking, girdling and pruning, maintaining a short and compact tree body, ventilation and light transmission, and forming a high-yield tree shape. This new cultivation model can maintain high and stable yields for as long as 20 years.