High-yield cultivation technology of spinach

Spinach is the most cold-resistant variety of green leafy vegetables and can survive the winter outdoors in areas south of the Yangtze River. In areas where temperatures drop to around -10 degrees Celsius, spinach can still be grown safely outdoors. In North, Northeast and Northwest China, spinach can also survive the winter successfully by setting up wind barriers and ground covers. The cold resistance of spinach is closely related to its growth, development and seedling age. Spinach has a deep taproot that is well developed and slightly thick, with a red upper part that stores nutrients, tastes sweet and is edible. The taproots are mainly distributed in the 25-30 cm tillage layer. The lateral roots are poorly developed, so it is not suitable for transplanting. Let’s learn about the high-yield cultivation techniques of spinach.

1. Key points of spring spinach planting technology

① Planting time: sow from early March to mid-April, and harvest in early to mid-May.

② Variety selection and sowing period: In spring, you should choose round-leaf varieties that bolt late and have large leaves. After the top 4-6 cm of soil thaws in early spring, sow as early as possible, generally in early March until mid-April. In the early stage of spring spinach growth, the temperature is low and the germination is slow, which is not conducive to the differentiation of leaf primordia; in the later stage, the temperature rises and the sunshine is prolonged, which is conducive to bolting and flowering. Therefore, the vegetative growth period is short, the number of leaves is small, bolting is easy, and the yield is low.

③Land preparation: Choose land that has not been planted with cruciferous vegetables or other field crops. Use well-rotted manure as base fertilizer, add 30 kg of nitrogen and potassium fertilizers, and then shallowly plow to make a flat bed about 1.3 meters wide for sowing.

④Sowing: Use the seed soaking method to germinate. Soak the seeds in warm water for 5-6 hours. After taking them out, place them at 15-20℃ for germination. Wash them with warm water once a day and they will germinate in 3-4 days. Generally, the broadcasting method is used. The growth cycle of spring spinach is short and the plants are small, so the sowing amount is increased to 5-7 kg per mu. It is best to use the wet sowing method when sowing in early spring. First, fill the bottom with water, then sow the seeds after the water has seeped in, and then cover with soil about 1 cm thick.

⑤Field management: Spring spinach needs to be covered with plastic film for heat preservation in the early stage. After the seedlings emerge, the film should be removed or replaced with a small arch shed. For spring spinach sown by the wet sowing method, the soil has sufficient moisture and the first watering is usually done when 2-3 true leaves grow. Starting from the second watering, apply 15 kg of urea per mu with water, or 20 kg of nitrogen and potassium fertilizers per mu. Apply quick-acting nitrogen fertilizer 15 days before harvest. Watering should be carried out according to the climate and soil moisture conditions to keep the soil moist.

⑥ Timely harvest: Harvest 40-60 days after sowing, and reach the harvest standard in early to mid-May.

2. Key points of summer spinach planting technology

Summer spinach, also known as "summer spinach", is the spinach that is on the market from July to August. The seedling growth period coincides with the high temperature and long daylight season, and the leaf primordia differentiate quickly, but the flower bud differentiation and bolting are also fast. The temperature is high, the evaporation is large, the respiration is vigorous, the plant accumulates less nutrients, the leaf area growth is limited, the quality is poor, and the yield is low. The key issues in summer spinach planting should be seedling emergence, seedling protection and healthy growth.

① Planting time: Sow from early to mid-June to July, and harvest about 50 days after sowing.

② Variety selection: Summer spinach should choose varieties that are heat-resistant, grow quickly, are resistant to bolting, are disease-resistant, have high yields and good quality. Varieties suitable for summer planting include: Dutch Biju No. 5 spinach F1, K5, Japanese Beifeng, Shaoxing spinach, etc. Guangdong round-leaf spinach, Nanjing large-leaf spinach, Huabo No. 1, etc. can also be chosen.

③ Determine the appropriate sowing period: the sowing period can be arranged about 50 days before the planned listing. At the same time, try to sow before the highest temperature in summer arrives, so that the seedlings can grow for a period of time before entering the high temperature period, which is conducive to obtaining higher yields. Therefore, the suitable sowing period for summer spinach is early to mid-June.

④ Soaking seeds for germination: Before sowing spinach in summer, the seeds must be soaked at low temperature for germination. The method includes: soaking in well water for 24-30 hours, wrapping with gauze, hanging in the well about 20 cm from the water surface, sinking the gauze bag into the water and washing it once a day, and sowing after 2-3 days when the seed radicle is exposed; or spreading the soaked seeds in a cool place indoors to germinate, pay attention to turning them over and maintaining a certain amount of moisture, and they can germinate after 5-6 days; or placing the soaked seeds at 15℃-20℃ to germinate, and they will germinate in 3-4 days.

⑤ Land preparation, fertilization and sowing: Before tilling the land , apply 2000-3000 kg of decomposed farmyard manure, 20 kg of three-element compound fertilizer and 10 kg of urea per 667 square meters. Also apply 1.5 kg of zinc fertilizer and 0.7 kg of boron fertilizer as base fertilizer. Shallow plowing and harrowing are used to make flat beds (including ridges) 1.1 meters wide. The bed surface must be flat and the bed should not be too long, about 15 meters is appropriate. Sow seeds using the wet sowing method before 10 a.m. and after 4 p.m. Water first, and after the water seeps in, sow the seeds and cover with 1.5-2 cm of fine soil. To ensure sufficient number of seedlings, the sowing amount can be increased to 8-10 kg per 667 square meters. After sowing, cover the bed surface with crop straw to reduce temperature and retain moisture, prevent erosion by heavy rain, and ensure that the seedlings are evenly planted. Try not to water before germination to prevent the soil from becoming compacted or the covering soil from being washed away when watering, exposing the seeds and affecting germination. Remove the covering in the evening or morning after the seedlings emerge.

⑥Field management:

a. Thinning: After the seedlings emerge, thin out the seedlings in areas where they are too dense.

b. Watering: During the summer spinach growth period, the principle of fertilizing and watering should be light and frequent. When watering for the first time, the water flow should be slow and the amount of water should be small to prevent the cotyledons from being soaked by mud and causing seedling death. Generally, water once every 5-7 days and keep the soil moist at all times to lower the ground temperature. Watering should be done in the early morning or evening, and use well water, not pond water or river water. During the growth period of seedlings, they do not like high temperatures and strong light. If necessary, a shed can be built to provide shade. Covering the material early in the morning and uncovering it late in the evening can both reduce temperature and prevent rain.

⑦Prevention and control of diseases and pests: The main diseases of spinach in summer are damping-off, downy mildew, anthracnose , and viral diseases. Prevention and control methods include: For sudden wilt, use 3000 times of Green Heng No. 1 or 1500 times of carbendazim to spray the ground and plants; for downy mildew, spray 600 times of 72% mancozeb cypermethrin, or 500 times of 58% metalaxyl wettable powder , or 500 times of 64% mancozeb wettable powder, or 200 times of 40% ethylene phosphazene wettable powder, and spray twice alternately every 7 days; for anthracnose, use 1000 times of 70% thiophanate-methyl, or 600 times of 50% carbendazim wettable powder, or 500 times of 70% mancozeb wettable powder, and spray 2-3 times alternately every 7 days; for viral diseases, aphids should be eliminated as soon as possible to reduce the chance of virus transmission, and prevention of leaf miners should be strengthened.

Spinach can be planted in many seasons and can also be cultivated in greenhouses. The above introduces spring cultivation techniques and summer cultivation techniques, but it is still necessary to master the details of field management to avoid too many problems.