Sour Jujube Seed Planting Methods and Key Cultivation Techniques

Sour jujube seed, a name in traditional Chinese medicine. This product is the seed of the sour jujube (Ziziphus jujuba var. spinosa), a plant in the Rhamnaceae family. Harvest when the fruit ripens in autumn, soak the fruit overnight, rub off the flesh, remove it, crush the pits with a stone mill, take out the seeds, and dry them in the sun. Its functions and indications are: nourishes the liver, calms the heart, soothes the nerves, and astringes sweat. Treats deficiency-type restlessness and insomnia, palpitations, vexation and thirst, and spontaneous sweating.

[Planting Techniques]

  Cultivation management techniques: Through measures such as pruning branches, trunk heading, and tending wild sour jujube to maturity, yields are noticeably higher than in the wild.

  (1) Grafting: Using wild sour jujube as rootstock and grafting sour jujube varieties with excellent qualities and high kernel yield can prompt wild sour jujube to form a stand as quickly as possible, with high yield and good quality.

  (2) Fertilizing: According to trials in production areas, applying 0.25 kg of urea or 20 kg of farmyard manure per sour jujube plant, followed by irrigation, has a significant yield-increasing effect compared with the wild state.

  (3) Ringing: Cutting a ring around the branch with a sharp knife is called "ringing." Production areas consider "ringing" to be one of the important measures for preventing sour jujube flower and fruit drop and increasing yield. The method is: in mid-to-late June, on the trunk 20 cm above the ground, cut a ring around it with a sharp knife, with a depth reaching the xylem as appropriate, but do not injure the xylem, so as not to destroy the cambium. The depth of the cut mark is about 3 mm. For young trees, "ringing" should be done every other year. The "ringing" position should move upward by 10-15 cm year by year. Through "ringing," nutrients are prevented from moving downward, ensuring the nutritional needs of flowering and fruiting, preventing flower and fruit drop, and achieving the goal of increasing yield.

[Cultivation Management]

  Pest and disease control:

  (1) Diseases: "Jujube witches' broom" is the main disease in sour jujube growth and is known as "jujube tree cancer." According to research, "jujube witches' broom" is caused by mycoplasma-like organisms. Before the flowering period, the leaves are basically normal, only slightly pale in color, and symptoms become obvious only after budding and flowering. The main manifestations are yellowing, clustering, small leaves, and upward curling leaf margins; leaf area is only 50% of normal, affecting the normal growth of sour jujube and even causing it to die. Diseased fruit are thinner and smaller than normal fruit, and the fruit surface colors unevenly, appearing mottled. At present, there is no effective control method.

  (2) Insect pests: The main insect pest of sour jujube is the yellow stinging caterpillar larva, which bites and eats the leaves, and in severe cases eats them all. Control method: In combination with pruning and orchard cleanup, concentrate on eliminating overwintering cocoons; during the larval stage, spray 500-fold Bacillus thuringiensis powder solution, once every 7-10 days, for 2-3 consecutive times.

  Loosening soil and weeding:

  In the nursery field, after the seedlings emerge evenly in the south, carry out shallow hoeing to loosen the soil and weed, and do this 2-3 times before the winter solstice. When the seedlings are 6-10 cm tall, apply 225 kg of ammonium sulfate per 1 sq m as a topdressing; when the seedlings are 30 cm tall, apply 180-225 kg of superphosphate per 1 sq m as a topdressing. To increase the fruit-setting rate of sour jujube, reasonable shaping and pruning must be carried out in spring, or tree-form transformation may be carried out by sawing off the part of the trunk above 1 m to promote multiple lateral branches and form a crown; ring barking may also be carried out. At full bloom, cut a ring around the trunk 10 cm above the ground, deep to the xylem, then cut another ring 0.5-0.6 cm away, and peel off the bark between the two rings. The wound begins to heal in about 20 d, and after 1 month the healed wound surface is more than 70%.

[Harvesting and Processing] Harvest when the fruit ripens in autumn, remove the flesh, dry the pits in the sun, crush the pits, sieve out the seed kernels, and dry them in the sun before use.