Detailed Explanation of Key Points for Delayed High-Yield Cultivation Techniques of Sweet Pepper
Sweet pepper is rich in nutrients and high in vitamin content, with diverse varieties and delicious flavor. The green fruits can be used in many dishes, and the mature fruits have even higher nutritional value. The product is tolerant to storage and transportation, has a long harvest period, and is widely cultivated nationwide. Taking advantage of these characteristics, after several years of research, a set of delayed high-yield cultivation techniques for medium tunnels has been summarized.
I. Variety Selection
For delayed cultivation in medium tunnels, mid-to-late maturing varieties with thick flesh and strong disease resistance should be selected. Such as Qiemen, Nongda 40, Jilin Sandaojin, etc.
????II. Raising Strong Seedlings
Strong seedlings are the basic condition for high yield. Standards for strong seedlings: seedling height 17-21 cm, stem diameter 0.3 cm. With 10-14 leaves, flower buds appearing at the top, and a calendar seedling age of 80-90 days. The key to raising strong seedlings is to increase soil temperature and improve nutritional conditions. For this reason, sweet pepper seedling raising should adopt two-stage seedling raising with nutrient soil.
1. First-stage seedling raising. The sowing date should be determined 80-90 days before the locally suitable planting time (when the soil temperature at 10 cm depth is stably above 12°C) (adding the days before emergence). For nutrition, use 50% mature garden soil that has never been planted with solanaceous vegetables, plus 30% decomposed horse manure and 20% high-quality farmyard manure. Add 300 g of ternary compound fertilizer with 15% each of nitrogen, phosphorus, and potassium per cubic meter. After fully mixing, spread 8-10 cm thick on the seedbed surface, water thoroughly, let it cool slightly, then sow, cover with soil, and then cover with a layer of plastic film to increase temperature and preserve moisture. After the seedlings emerge, the plastic film can be removed. To ensure timely planting. Raise seedlings in cold frames or medium and small tunnels according to local conditions. After emergence, control the daytime temperature at 23°C-25°C and the nighttime temperature at 17°C-15°C. Strictly control watering to prevent excessive vegetative growth. Transplant when 3 true leaves appear.
2. Second-stage seedling raising uses 70% garden soil plus 30% high-quality fine livestock manure. Add 400 g of ternary compound fertilizer with 15% each of nitrogen, phosphorus, and potassium per cubic meter. Make nutrient blocks or use nutrient pots for seedling raising. When transplanting seedlings, transplant single or double plants according to the spread of the variety. During the seedling period, use measures such as temperature regulation and water control to achieve balanced aboveground and underground growth and cultivate strong seedlings. Within one week after transplanting, maintain 25°C-30°C during the day; after the seedlings recover, maintain 20°C-25°C during the day and 17°C-15°C at night. Conduct low-temperature hardening 10-15 days before planting.
????III. Planting
1. Fine land preparation and fertilization. Because the growth period of delayed cultivation of sweet pepper is long, the amount of base fertilizer should be appropriately increased. Apply 6000 kg of high-quality manure, 50 kg of diammonium phosphate, and 50 kg of cake fertilizer per 667 sq m, incorporated with deep plowing. After deep plowing, harrow finely and level. Make ridges 50 cm wide from one side of the field. Then cover the two 50 cm ridges with plastic film, extending both sides 6-8 cm beyond the outside of the ridges, pull the bed surface flat, and press the sides firmly with soil.
2. Planting. When planting, first open planting holes on the ridges at 30-33 cm spacing, then plant the seedlings with nutrient blocks into the planting holes, cover with half soil, water thoroughly to stabilize the seedlings, seal the holes the next day, and press the plastic film around the planting holes firmly.
????IV. Open-Field Cultivation Management
Open-field cultivation management should focus mainly on disease prevention and protecting the plants. Before the arrival of high summer temperatures, the main focus should be promoting plant growth, striving to close the rows before the large tuber stage, and increasing disease resistance during the high-temperature season. Entering the full fruiting period, strengthen fertilizer and water management and pest and disease control. Keep the leaves vigorous. Water once 3-4 days after planting to help the seedlings recover, then do not water again, appropriately promoting root growth and controlling vine growth. Prevent excessive vegetative growth and flower drop. After the first fruit sets (that is, when the fruit grows to 3-4 cm), begin watering, and afterward the soil surface must not be allowed to dry and crack. Water every 7-8 days, and apply fertilizer with the water. Apply 15 kg of urea or 20 kg of diammonium phosphate per 667 sq m. Foliar spraying of 0.3% potassium dihydrogen phosphate can also be used to prevent premature aging.
????V. Making the Arch Frame
Before the first frost, make an arch frame 3 m wide, with unlimited length. Make one arch frame every 1 m. Install only a central post, no side posts. The material for the central post can be adapted to local conditions and sourced locally. Use leftover wood branches from logging or bamboo strips - 1.5 m long, buried 20 cm underground, with a tunnel height of 1.3 m. Use bamboo strips on the central post to form the arch frame.
????VI. Preparation Before Covering the Tunnel
4-5 days before the arrival of the first frost, promptly pick all sweet peppers that have reached commercial standards and sell them nearby. Then apply 20-25 kg of ammonium sulfate per 667 sq m and irrigate heavily once.
????VII. Covering the Tunnel
When the daily average temperature drops to 13°C, 2-3 days before the arrival of the first frost, choose a sunny and windless day to cover with film. Use two sheets of plastic film, covering with an overlapping seam in the middle, to facilitate ventilation and cooling and regulate the temperature inside the tunnel. After covering with film, secure it with film-pressing lines to prevent strong winds from blowing the film off.
VIII. Strengthen Temperature Management
In the early stage, the main focus should be controlling temperature rise; in the later stage, the main focus should be heat preservation. After covering the tunnel, because the outside temperature is relatively high, and because fertilization and irrigation were carried out before covering the tunnel to promote excessive growth of sweet pepper, attention should be paid to ventilation and cooling for control. Keep the temperature inside the tunnel at 25°C-30°C. Appropriately control growth. In the later stage, as the outside temperature drops, heat preservation measures should be strengthened to ensure normal growth of sweet pepper. During the day, ventilation should be closed 2 hours before sunset to increase the temperature inside the tunnel and prevent too great a drop in nighttime temperature from affecting growth.
????IX. Strictly Control Moisture
Sweet pepper has a shallow root system, and the root mass prefers moisture but fears waterlogging. For this reason, after covering the tunnel, adopt frequent light irrigation to prevent water shortage and water accumulation. Irrigation should be carried out on sunny mornings, and ventilation should be provided in time to remove moisture and prevent disease occurrence.
????X. Pest and Disease Control
In delayed cultivation of sweet pepper, the growth period is long, and improper management can cause various diseases. With open-field management in the early stage and tunnel management in the later stage, combine artificial control of disease occurrence conditions with chemicals for prevention and control.
????XI. Timely Harvest
In the early stage, harvest promptly as the fruits mature. When the tunnel temperature drops to 5°C-6°C, harvest all fruits to prevent freezing damage. After harvesting, use the jar storage method to keep them fresh and supply the New Year's Day and Spring Festival markets.