Detailed Explanation of Key Techniques for High-Yield Cultivation of Wumei (Chinese Plum)

Wumei (Chinese Plum), also known as sour plum, plum, green plum, white plum, plum fruit, huangzai, etc. The flesh is used medicinally, with effects including astringing the lungs to stop coughing, astringing the intestines to stop diarrhea, harmonizing the stomach to calm roundworms, promoting fluid production to quench thirst, and securing menstruation to stop bleeding. It mainly treats chronic cough due to lung deficiency, bloody stool, bloody urine, uterine bleeding, thirst with deficiency heat, abdominal pain due to roundworm agitation, and vomiting. External application can treat vitiligo and corns. The main producing areas include Fujian, Sichuan, Hunan, Zhejiang and other provinces.

Morphological Characteristics

It is a deciduous small tree of the genus Cerasus in the Rosaceae family, reaching a height of up to 10 m. The bark is light gray, with many branches. Simple leaves are alternate; petioles are present, usually with glands; on young branches, the base of the petiole has 2 linear stipules, the stipule margins have irregular fine sharp serrations; the leaf blade is ovate to oblong-ovate, 4-9 cm long and 2.4-4 cm wide, the apex is long caudate-acuminate, the base is broadly cuneate, the margin has fine sharp serrations, and along the veins on the underside there are yellowish-brown hairs. Flowers are solitary or in clusters of 2, white or pink, fragrant, usually opening before the leaves, with short pedicels; bracts are scale-like, brown; the calyx tube is campanulate, with 5 lobes, the base connate with the receptacle; petals are single or double, usually 5, broadly obovate; stamens are numerous, inserted on the rim of the receptacle; pistil 1, the ovary densely hairy, the style slender and curved. The drupe is spherical, about 2-3 cm in diameter, with a shallow groove on one side.

I. Growth Habits Wumei prefers a warm, humid environment with ample sunlight. It is cold-tolerant, drought-tolerant, and afraid of waterlogging. It has low requirements for soil, but deep, loose, fertile sandy loam is best. Heavy clay and saline-alkali land are not suitable for planting.

II. Land Preparation and Fertilization Select a field with high terrain and good drainage and cultivate it finely. In combination with land preparation, apply sufficient base fertilizer: 3000 kg of farmyard manure per mu, 20 kg of urea, and 50 kg of phosphate and potassium fertilizer. Then make raised beds 1.5 wide and wait for sowing.

III. Sowing Wumei is propagated by seed, and can also be propagated by grafting and cuttings. Seed propagation: the seeds must be treated before sowing. In June, pile the collected seeds to rot, take them out after about 10 days, and rub them clean in running water. Half a month before sowing, soak them in human urine for 15 days. Then remove them, rinse off the urine and sow. The sowing period can be winter sowing or spring sowing. Before sowing, sow the Wumei seeds into the soil at a row spacing of 25×10 cm. Water to preserve soil moisture and promote seedling emergence. The sowing rate is 50 kg per mu. Grafting propagation: the rootstock uses 1-2 year old apricot or plum seedlings; the scion uses the current-year vegetative shoots of Wumei that has already flowered and fruited and is of a superior variety. Carry it out directly in early spring, using the T-shaped grafting method. Cutting propagation: at the Autumn Equinox or after flowering in early spring, cut 1-year-old robust branches into cuttings about 20 cm long, each with 3 nodes. Cut the lower end near a node into a horseshoe-shaped slant. Tie every 50 cuttings into a bundle, soak the lower slant end in a 500 PPM rooting powder (ABT) or acetic acid (NAA) solution to a soaking height of 2 cm for 10 seconds. Transplanting: before sprouting in early spring, plant the Wumei seedlings in the prepared field at a row spacing of 3×2 m. Water to preserve soil moisture and promote survival.

IV. Field Management After the Wumei seedlings survive transplanting, attention should be paid to cultivating and weeding. Water frequently in dry weather and drain promptly in rainy weather. After harvesting the fruit in May-June, apply a topdressing once: 10 kg of urea and 50 kg of potassium dihydrogen phosphate per mu. Apply farmyard manure once in winter. During the growth of the Wumei tree, in order to increase yield, it should be trained and pruned to form a natural open-center tree shape with a spreading crown, round outside and hollow inside, a strong framework, and a low crown with high yield. In order to increase income and achieve the goal of using short-term crops to support long-term ones, in the first few years after planting, short-stemmed, short-growing-season crops can be appropriately intercropped between the rows and plants.

V. Pest and Disease Control The main pest and disease of Wumei is anthracnose, which can be controlled by spraying with a 1000-fold dilution of 50% carbendazim in the early stage of the disease. Spray once every 7 days, for 3 consecutive sprays. Also, during winter pruning, cut off diseased and dead branches. The main insect pest is the longhorn beetle, which can be killed by inserting a cotton ball dipped in dichlorvos into the insect hole. Aphids can be controlled with pirimicarb.

VI. Harvesting and Processing Seedling-grown Wumei bears fruit in 6-7 years; grafted seedlings bear fruit in 2-3 years. After 10 years, it enters the full fruiting period. It can be picked in May-June when the fruit skin turns greenish-yellow. Put the collected fresh fruit into a bamboo basket and shake it to remove the fuzz, take it out and wash it clean with water, dry it in the sun or by heat, and remove the pit to obtain Wumei flesh. A 10-15 year old Wumei tree can produce 50-100 kg of fruit per tree.