Detailed Explanation of Key Cultivation Techniques for Star Anise as a Chinese Medicinal Herb

I. Site Selection and Land Preparation

Star aniseshould be planted on gently sloping, leeward hillsides at an altitude of 500-800 m, with humidity above 85%, free of frost damage, freeze damage and devastating pests and diseases, and close to a water source. Prepare the land by cutting strips or directly digging planting holes, with a spacing of 3.5 m-4.0 m between plants and rows, a planting density of 705 plants/ha, and planting holes 60 cm wide and 50 cm deep. After allowing them to weather for 15 d, backfill with 15 kg of decomposed farmyard manure (pig, cattle, chicken manure, etc.) per hole + 1.0-1.5 kg of cake bran (or phosphate fertilizer) per hole or 5 kg of superphosphate per hole mixed with soil, then cover with 20 cm of topsoil.

II. Planting Methods

1. Seed collection and seed treatment: Select vigorous mature trees with a well-developed crown, abundant fruiting, excellent quality and no pests or diseases as mother trees for seed collection. The main fruit ripening period is in late October, and fruits are harvested before they split open. When collecting seeds, use a wooden hook to pull down the fruiting branches or pick the fruits by hand; do not strike with bamboo poles or shake the branches or break off branches, so as to protect the mother trees. Every 100 kg of fresh fruit can yield 18-24 kg of seeds, with a 1000-seed weight of 111 g. After the seed fruits are collected, spread them indoors to dry in the air, turning them frequently, and remove the seeds and impurities. Sow immediately after collection. Seed treatment involves mixing the seeds with 3-4 times their volume of yellow clay and a small amount of clean water, stirring evenly so that each seed is coated with a layer of yellow mud, then storing them in a cool place until sowing time. During storage, protect against heat, rats and moisture loss.

2. Raising seedlings: The nursery should be selected in a place with abundant water, fertile soil, a shady environment, good drainage, and protection from mountain torrents and direct sunlight. Plow and harrow the land, break up the soil evenly, and make beds. Apply sufficient base fertilizer in combination with deep plowing. The bed surface is 30 cm wide, and drainage ditches are dug in the center and around the nursery to facilitate drainage and prevent waterlogging.

Use drilling. The row spacing is 15-20 cm, the sowing furrows should be level, the row spacing should be uniform, and the sowing furrow depth is 4 cm. Sow 1 seed per spot at a spacing of 3-4 cm. After sowing, cover with burned turf mixed with fine soil, about 3 cm thick. To prevent the soil from drying out and rain from washing away the bed surface, and to ensure rapid and uniform germination, cover with rice straw after sowing. Before the seedlings emerge, water frequently to promote seed germination and emergence. Topdress when the seedlings are 3-4 cm tall. Topdressing can be combined with intertillage and weeding, with nitrogen fertilizer as the main type in the early stage. In the 2nd and 3rd years, intertillage, weeding, topdressing and thinning are required. One-year-old seedlings are 30-45 cm tall, two-year-old seedlings are 45-60 cm tall, and three-year-old seedlings are over 1.3 m tall.

3. Planting: The density is 750 plants/ha2, with a spacing of 4 m×3 m or 4 m×5 m between plants and rows. Field planting and afforestation are carried out in August-October or in January-February of the second year after land preparation, before the new buds sprout. When using bag seedlings for afforestation, tear off the nutrient bag at planting time, protect the nutrient soil, firm the soil after covering, straighten the seedlings, and water thoroughly to settle the roots. After planting, ensure 50% shade for the seedlings, water frequently, and keep the soil moist and loose. Apply water-soluble fertilizer once each during the bud-breaking stage and the leaf-expanding stage, watering with a 0.3% urea solution, 6-8 kg per plant each time. If missing plants are found, replant promptly with seedlings of the same age.

4. Field management

Young trees: From the current year until the 2nd-6th years, loosen the soil and weed 1-2 times each year, with a loosening depth of 3-5 cm. If crops have already been intercropped in the forest land, this should be done in combination with tending the crops. For fruit-producing forests, apply 0.03-0.05 kg of compound fertilizer (N:P2O5:K2O=15:10:15) per plant in the year of afforestation, 0.2-0.3 kg of compound fertilizer per plant in the 2nd-3rd years, and 0.5-0.8 kg of compound fertilizer per plant in the 4th-5th years. For leaf-producing forests, apply 0.05-1.0 kg of urea per plant in the 1st year, and fertilize twice in the 2nd year, applying 0.01-0.15 kg of urea or compound fertilizer per plant each time. Use ring-shaped fertilization, apply the fertilizer evenly, and cover with soil. If foliar fertilization is carried out, spray 0.1%-0.5% urea or monopotassium phosphate during the vigorous growth period each year in April-May. Forest land intercropping: short-stalked crops and green manure crops can be intercropped. Crops such as peanut, sweet potato, beans and ginger; green manures such as Chinese milk vetch, clover and alfalfa. Training and pruning: For fruit-producing forests, top the tree when it reaches 2 m to promote branching, retaining 3-4 tiers per plant and 3-4 main branches per tier, with the first tier 40-50 cm above the ground and the 2nd to 4th tiers spaced 40-70 cm apart, and make the structure reasonable, with upper and lower tiers staggered and not overlapping. For fruit-producing forests established with seedlings, protect the main trunk and side branches, and prune dead branches and pest- and disease-infested branches; for fruit-producing forests established with grafted seedlings, in the 1st-2nd years after afforestation, retain only 1 sprouting main trunk and remove all other sprouts. Promptly prune water sprouts, crossing branches, weak branches and pest- and disease-infested branches. For leaf-producing forests, when the height reaches 1.5 m, cut off the top shoot to control height growth and promote side branch development, and select and retain 4-6 vigorous sprouting branches on the cut trunk as main branches, distributed as evenly as possible in the four directions of east, west, south and north. In combination with shaping, appropriately prune inner branches, shaded branches and weak branches; prune pest- and disease-infested branches and dead branches.

Fruiting trees: After star anise enters the full production period, carry out shallow hoeing to 7-10 cm once each year after summer rains and before autumn arrives. Weed once each year in February-March and August-September. For fruit-producing forests, apply 0.8-1.0 kg of compound fertilizer and 0.2-0.3 kg of potassium fertilizer per plant each year in March-April; apply 1.0-1.5 kg of compound fertilizer per plant in June-July; in October-December, in combination with post-harvest orchard cleaning, green manuring and soil improvement, apply 10-20 kg of decomposed farmyard manure and 1.5-2.0 kg of compound fertilizer per plant. For leaf-producing forests, apply 0.5-1.0 kg of compound fertilizer per plant each year in March-April; apply 0.5-1.0 kg of compound fertilizer per plant in September-October; in November-December, in combination with post-harvest orchard cleaning, green manuring and soil improvement, apply 10-20 kg of decomposed farmyard manure and 1.0 kg of phosphate fertilizer per plant as a mixed application.