Detailed Explanation of High-Efficiency, High-Yield Cultivation Techniques for Wild Jujube Seed
Wild jujube seed is the dried mature seed of the Rhamnaceae plant wild jujube Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H.F. Chou. It was first recorded in the Shennong Bencao Jing and listed as a superior-grade herb. Its flavor is sweet and sour, and its nature is neutral. It enters the Liver, Gallbladder, and Heart meridians. It tonifies the liver, calms the heart, soothes the spirit, promotes fluid production, and reduces sweating. It is used for deficiency-type restlessness and insomnia, palpitations with frequent dreaming, scanty fluids and dry mouth, weakness with excessive sweating, and thirst from fluid damage. It grows on sunny slopes or dry, barren soil, often forming thickets. It is mainly produced in Xingtai, Neiqiu, Handan, and Chengde in Hebei, as well as Liaoning, Inner Mongolia, Shandong, Shanxi, Henan, Shaanxi, Gansu, Ningxia, and Sichuan, with the largest output in Handan, Hebei. It is sold throughout the country and exported. It is a traditional commonly used Chinese medicinal material in China. It has a long history of use and has long enjoyed a high reputation at home and abroad. So, how can wild jujube seed be planted for high efficiency and increased yield? And what issues need attention during cultivation? Here is an introduction to the key points of high-efficiency cultivation techniques for wild jujube seed:
(1) Site Selection and Land Preparation
Select sandy soil with deep, fertile soil layers and good drainage. Prepare the land in advance before transplanting to allow the soil to mature. First cut down and clear the shrubs and weeds in the plot, then break up the soil clods, and according to the terrain, make beds along the slope (about 100-130 cm wide) or fish-scale ditches, etc. Dig deep pits and apply sufficient base fertilizer, applying 1500-2000 kg of barnyard manure per 667 sq m, then rake level and fine. On the deeply plowed and finely prepared ground, open an irrigation ditch every 15-20 m, then between the two ditches, set out lines and mark points at a row spacing of 1 m to make ridges, with ridge height 15 cm, ridge surface width 35 cm, and ridge bottom width 50 cm, with 2 rows per ridge.
(2) Planting Methods
Seed propagation: Select superior mother plants that grow vigorously, bear fruit year after year with high yield, and are free of pests and diseases. Harvest mature reddish-brown fruits from September to October, pile them in a shady, damp place to let the flesh rot, then rub and wash out the seeds in clear water. Mix with wet sand at 3 times the seed volume, and either dig a pit outdoors in a sunny, dry place for stratified sand storage, or place the seeds in a wooden box and store them indoors in a cool, moist place. In the following spring, when the seeds crack and show white, they can be sown. Spring sowing is done from late March to early April, and autumn sowing is done in late October. Open furrows at a row spacing of 30 cm, about 3 cm deep, evenly scatter the seeds into the furrows, cover with soil and press lightly, water, and cover with grass to preserve warmth and moisture; seedlings emerge in about 10 days. After the seedlings are uniform, remove the covering grass. Cultivate for 1-2 years, and when the seedlings are about 80 cm tall, they can be removed from the nursery. Open holes for permanent planting at a row and plant spacing of 2×1 m, with holes 30 cm deep, 1 plant per hole, fill with soil and firm it, then water.
Division propagation: Select superior mother plants. In winter or spring during the plant's dormant period, dig a ring-shaped ditch about 40 cm wide at a distance of 15-20 cm from the trunk, deep enough to expose the horizontal roots, and cut the horizontal roots in the ditch. When the root-sucker seedlings are about 3 cm tall, select and keep the strong seedlings for cultivation, fertilize and fill the ditch with soil, then open a second ditch 30 cm away from the root-sucker seedlings, cut the roots connected to the original plant to encourage the root seedlings to grow their own fibrous roots, and after several days fill the ditch level. After 1 year of cultivation, they can be planted out.
(3) Field Management
1. Cultivation and Weeding: During the seedling stage, loosen the soil and weed in time. After permanent planting, loosen the soil and weed 2-3 times each year. After permanent planting, in the first few years, beans, vegetables, or annual herbaceous Chinese medicinal materials can be intercropped in the field, and cultivation, weeding, and topdressing can be carried out in combination with intercropping.
2. Topdressing: When the seedlings are 6-10 cm tall, apply 10-15 kg of urea or ammonium sulfate per 667 sq m; when the seedlings are 30-40 cm tall, open furrows between the rows and apply 1000 kg of barnyard manure and 15 kg of superphosphate per 667 sq m, then water after application. Once entering the fruiting stage, after harvesting fruit each autumn, apply 50 kg of farmyard manure, 2 kg of superphosphate, and 1 kg of ammonium bicarbonate per plant, which has an obvious effect on increasing yield and rejuvenating tree vigor, and also noticeably reduces fruit drop. In addition, during the growing season, use a mixture of 0.1%-1% urea and 0.3% potassium dihydrogen phosphate for foliar topdressing once a month, which also has a significant yield-increasing effect.
3. Spraying Plant Growth Regulators: In early June during full bloom, spray 10 mg/kg naphthaleneacetic acid (NAA) or 8-10 mg/kg 2,4-D. In mid-July during the young fruit stage, spray 30 mg/kg 2,4-D or 50 mg/kg naphthaleneacetic acid (NAA) once every 3-4 days, for 2 consecutive sprays.
4. Spraying Water and Irrigation: During full bloom, choose a sunny, windless afternoon or evening, and use a sprayer to evenly spray clear water onto the jujube flowers once every 3-5 days or carry out field irrigation, which can reduce flower and fruit drop and increase the fruit-setting rate.
5. Pinching the Jujube Head: In the early full-bloom stage, when the new jujube head branches reach more than 30 cm in length, pinch the jujube heads that are not being used for renewal, leaving 3-4 secondary branches, which can sprout into robust jujube spurs. These are the main fruiting mother branches of wild jujube and can bloom and bear fruit year after year.
6. Keeping Bees in the Jujube Orchard: The wild jujube tree is an insect-pollinated plant. Keeping bees during the flowering period and using honeybees to strengthen pollination can increase the fruit-setting rate by about 1 time and increase yield by more than 20%.
7. Pruning: After permanent planting, when the trunk diameter reaches about 3 cm, determine the trunk at a height of 80 cm. During winter pruning, keep 5-7 branches on the upper part of the trunk, and cut off all branches below 80 cm and near the ground, so as to form a thick, strong main trunk and a clear crown. The specific method is as follows:
7.1 Pruning of Young Trees: The main purpose is to expand the crown and develop a sturdy framework. After permanent planting, when the trunk diameter is about 3 cm, determine the trunk at a height of 80 cm. In the first year, from the newly sprouted branches, select and keep 3-4 strong branches and cultivate them into the first layer of main branches, spreading radially in all directions to form the first layer of the crown. The central trunk continues to grow upward, and small side branches appearing on it may be appropriately retained as auxiliary fruiting branches. Erect, vigorous water sprouts sprouting on each main branch can be cut off from the base; parallel, thin, and weak branches can be retained to facilitate the normal growth of the main branches. The secondary branches of the jujube head on the main and side branches should be retained, as these are the main fruiting sites on the wild jujube tree. Topping the branch tips that have extended growth for 3 consecutive years (removing the main bud) helps rejuvenate the jujube spurs on each secondary branch. In the second year, from the new branches produced that year, again select and keep 3-4 strong branches and cultivate them into the second layer of main branches, forming the second layer of the crown. The spacing between each layer is 40-50 cm. By the third year, cut the top at 40 cm from the third layer of the crown, so that the overall tree height is controlled at about 2 m. Through 3 years of shaping and pruning, a high-yield tree form with a clear layered main trunk can be formed, with a full crown, good ventilation and light penetration, three-dimensional fruiting, and convenient management.