Cultivation Methods for the Health-Boosting Nutritional Herb Perilla

Perilla belongs to the Lamiaceae family, genus Perilla, and is an annual herbaceous plant. Its roots, stems, leaves, and seeds can all be used as medicine. The tender branches and leaves have a distinctive aroma and can be used as a seasoning and eaten as a vegetable. It is an excellent export vegetable that generates foreign exchange. The cultivation techniques are described below.

I. Cultivation Techniques:

1. Sowing and seedling raising. Choose the Japanese leaf-eating perilla or the domestic large-leaf perilla variety. Select fertile soil that does not easily form a hard surface layer, has good aeration and water retention, and is relatively rich in humus as the seedbed. For each mu of seedbed, first apply 200 kg of decomposed chicken and sheep manure or 400 kg of concentrated human manure and urine evenly on the surface. Turn it into the soil, expose the soil clods to the sun for 10 days, then broadcast 5 kg of compound fertilizer and 2 kg of urea as base fertilizer. After mixing the fertilizer and soil evenly and raking it level and fine, make the bed. The bed height is 15 cm, and the length and width depend on the terrain and ease of operation. Sow in mid to late March. Before sowing, spray the bed surface with a 300-fold dilution of pendimethalin solution for weed control. Sow 4 days after spraying, scatter the seeds evenly on the bed surface, cover with a thin layer of soil and rice straw, water thoroughly, and either lay film flat over the bed or set up a small arched frame with film pressed flat. During the seedling period, apply dilute human manure and urine 2—3 times, thin the seedlings 3 times, and set the final spacing at about 3 cm. To prevent excessive seedling growth and excessive soil moisture, the film must be uncovered frequently for ventilation. Transplant when the seedlings are about 45 days old.

2. Land preparation and planting. Perilla can be cultivated in all types of soil, but loam and sandy loam with a pH value of 6-6.5 are best. The field base fertilizer is mainly organic fertilizer. For each mu, apply 5,000 kg of decomposed garbage fertilizer and 3,000 kg of manure, or 1,500 kg of chicken and sheep manure and 100 kg of compound fertilizer. After plowing, exposing the soil clods to the sun, breaking them fine, and raking level, make ridges. The ridge surface width is 90 cm, and the ridge ditch width and depth are each 30 cm. Plant from late April to early May. Plant 6 rows per ridge, with a plant and row spacing of 15 cm×15 cm, and 15,000—20,000 plants per mu. To eliminate weeds and prevent cutworms from damaging the seedlings, 3 days before planting, spray the soil surface with pendimethalin and scatter bran mixed with a 500-fold dilution of trichlorfon on the ridge surface for trapping and killing.

3. Leaf picking and shoot removal. Twenty days after planting perilla, for plants that have grown 5 stem nodes, all leaves and branches below the 4th stem node should be removed to promote robust plant growth.

One week after removing the first flush of leaves, when the leaves at the 5th stem node have a horizontal width of more than 10 cm, leaf harvesting can begin, picking 2 pairs of leaves each time. Also remove the axillary buds growing on the upper stem nodes from the stem. Late May to early August is the peak leaf-picking period, and picking can be done once every 3—4 days. In early September, the plants begin to grow flower clusters. At this time, for those kept for leaves rather than seeds, 3 pairs of leaves can be retained while pinching off the growing tips and removing branches, so that they reach the standard for finished leaves. Each perilla plant can have 36-44 leaves picked over the year, and each mu can produce 1,700-2,000 kg of fresh leaves.

4. Fertilization and pest control. After the seedlings are planted and have survived, apply a topdressing fertilizer around the roots once every half month, each time applying 2,500 kg of human manure and urine or 10 kg of urea per mu of field. To accelerate leaf growth and improve leaf quality, apply a 0.5% urea solution as a foliar topdressing once a month. If high temperature and drought occur during the growing period, water in the morning and evening to combat the drought.

The main pests damaging perilla include spider mites, aphids, green caterpillars, and grasshoppers. Control can be carried out by choosing an 80% dichlorvos emulsifiable concentrate 800-1000-fold dilution or a 60% fenvalerate emulsion 10,000-fold dilution, and spraying should be done after each batch of leaves is picked.

II. Seed collection:

Seed collection can be carried out in a seed-production field, or some plants can be selected and retained in the main field as seed plants. However, red and green perilla must be grown in absolute isolation, and variant plants must be removed to avoid seed mixing and degeneration. To concentrate nutrients so that the seeds in the middle and lower parts develop and mature, the upper 1/3 of the flower cluster should be cut off. The seeds can be harvested once they turn brown.