Detailed explanation of perilla seed cultivation methods, this traditional Chinese medicine is highly favored at home and abroad
Perilla seed, originally named "Su", is the dried mature fruit of the Labiatae plant Perilla frutescens (L.) Britt. It is harvested in autumn when the fruit is ripe, impurities are removed, and it is sun-dried. It was first recorded in "Mingyi Bielu" and listed as a medium-grade drug. Its nature is pungent, warm; it enters the lung meridian. It has the effects of directing qi downward and transforming phlegm, relieving cough and calming panting, and moistening the intestines to relieve constipation. It is mainly used for phlegm obstruction with rebellious qi, cough and panting, dry intestines and constipation, and other conditions. It is a medicinal and edible dual-use medicinal material.
Perilla has a history of nearly 2000 years of cultivation and application in China, mainly used for medicinal, oil, spice, food, and other purposes. Its leaves (perilla leaves), stems (perilla stems), and fruits (perilla seeds) can all be used as medicine. The tender leaves can be eaten raw or used in soup, and the stems and leaves can be pickled. In recent years, because of its unique active substances and nutritional components, perilla has become a multi-purpose plant of worldwide attention with very high economic value. Russia, Japan, South Korea, the United States, Canada, and other countries have carried out large-scale commercial cultivation of Perilla genus plants and developed dozens of perilla products such as edible oil, medicines, pickled products, and cosmetics. So, how is perilla seed, which is favored at home and abroad, cultivated? The cultivation techniques are introduced as follows:
Original plant of perilla seed
[Growth habits]
Perilla has the characteristics of shade tolerance, light preference, and fertilizer preference; its drought resistance is relatively poor, it prefers moisture and fears waterlogging, and it is not suitable for planting in saline-alkali land or poorly drained land. Seeds germinate at around 5°C. The suitable germination temperature is around 25°C. The suitable temperature for growth and development is 15-25°C. It grows well under conditions of moist soil and sufficient water, and its quality is crisp and tender. During drought, the plant grows poorly; but with too much water, it is prone to root rot and death. It has no strict requirements for soil, and can be planted in front of and behind houses, beside ditches, at the edges of fields, under tree shade, and between rows of large crops.
[Cultivation techniques]
1. Land selection and preparation
For the seedling site, choose a place with loose, fertile, well-drained sandy loam soil and convenient irrigation. Before sowing, first plow the soil, fully refine and level it, and apply 1500 kg of decomposed barnyard manure per mu as base fertilizer in combination with land preparation, then make high beds 1.3 m wide for sowing. For the transplanting site, choose a plot with sufficient sunlight, good drainage, and loose, fertile soil for planting. Before transplanting, first plow the soil to a depth of 15 cm, break up the clods, level and harrow finely, make high beds 1.3 m wide, open bed furrows 40 cm wide and 15-20 cm deep, and properly arrange drainage ditches around the perimeter.
2. Planting methods
1. Seed collection and seed treatment
Use seed propagation, and direct seeding or seedling transplanting may be used. Select robust plants with purple on both sides of the leaves and no pests or diseases as mother plants for seed collection. Apply additional phosphorus and potassium fertilizer in the field to promote more fruit setting and full, plump seeds. From late September to mid-October, when 2/3 of the fruit calyxes on the lower part of the ear turn brown, promptly cut off the mature ears, sun-dry them, thresh them, winnow them clean, and store them for later use.
2. Sowing methods
(1) Seedling raising: Sow at the appropriate time around Qingming. On the leveled and finely harrowed bed surface, open furrows horizontally at a row spacing of 15-20 cm for drilling. When sowing, mix the seeds with burnt soil ash, evenly scatter them into the furrows, and cover with fine soil, just enough so that the seeds are not visible. Finally, cover the bed surface with grass to keep it warm and moist, and seedlings will emerge in 10-15 days. After emergence, remove the covering grass and carry out intertillage, weeding, and topdressing. When the seedlings are 5 cm high, thin them, removing dense and weak seedlings, and maintain a plant spacing of 3-5 cm. After thinning, apply 1500 kg of dilute human and livestock manure water per mu; when the seedlings are 7-9 cm high, in combination with final thinning, apply another 1500 kg of dilute human and livestock manure water per mu. When the seedlings are 10-15 cm high and have 4 pairs of true leaves, they can be transplanted. The seeding rate is about 1 kg per mu. When seeds are sufficient, broadcast sowing may also be used.
(2) Direct seeding: The suitable period is sowing around Qingming. On the prepared planting land, dig holes at a row spacing of 25-30 cm and a plant spacing of 25 cm, and at a sowing rate of 300 g per mu, mix the seeds with burnt soil ash and human and livestock urine evenly into seed ash, and scatter a small amount into the holes. After sowing, cover with fine fertile soil, just enough so that the seeds are not visible. Keep the soil moist, and seedlings will emerge in 10-15 days. In mid-May, when the seedlings are 5-7 cm high, thin them, leaving 2-3 robust seedlings per hole. Other management methods are the same as for seedling raising.
3. Seedling stage management
There are many weeds during the seedling stage, so they should be pulled out in time. Combine weeding with intertillage, generally requiring 3-4 intertillage operations.
4. Planting and management
For spring seedling raising, transplant in mid-to-late May, and no later than the end of June. Choose cloudy days for transplanting. When the soil is dry, first water the seedbed thoroughly 1 day before transplanting so that the soil is moist, and it is advisable to dig out the seedlings with their roots intact to help survival. When planting, dig holes at a row and plant spacing of 25×30 cm, about 10 cm deep, loosen and level the bottom of the holes, first apply an appropriate amount of burnt soil ash, and mix it evenly with the subsoil. Then, plant 2-3 robust seedlings per hole. After planting, cover with soil and press firmly so that the root system spreads out, and finally water once with rooting water. After transplanting and survival, carry out 1 loosening of the soil and weeding within 7 days, and at the same time apply 1000 kg of human and livestock manure water per mu; the 2nd time, before the plants close in rows, in combination with intertillage, apply 2000 kg of human and livestock manure water per mu. For direct-seeded plants, carry out intertillage, weeding, and topdressing once each at thinning, final thinning, and before row closure. The 1st time, apply 1000 kg of dilute human and livestock manure water per mu; the 2nd time, apply 1500 kg of human and livestock manure water per mu; the 3rd time, apply 2000 kg of slightly concentrated human and livestock manure water per mu. After sowing or transplanting, if dry weather occurs, attention should be paid to timely watering to protect the seedlings. During the rainy season and after heavy irrigation, promptly clean the ditches and drain excess water to prevent root rot from water accumulation.
[Pest and disease control]
1. Diseases
1. Septoria leaf spot
It occurs from June until before harvest. In the early stage of the disease, brown or black small spots appear on the leaf surface, later expanding into large diseased spots, and after drying, holes form and the leaves fall off.
Control methods: (1) Reasonable close planting, improve ventilation and light transmission conditions, pay attention to drainage, and reduce field humidity;
(2) In the early stage of the disease, spray 65% zineb 600-800 times liquid or 1:1:200 Bordeaux mixture, once every 7 days, spraying continuously 2-3 times. Stop spraying within 15 days before harvest.