How to Grow Sweet Peppers in a Medium Tunnel? Detailed High-Yield and High-Efficiency Cultivation Techniques
Sweet peppers like warmth but fear intense heat, and like moisture but fear waterlogging. The most suitable growing temperatures: between 20-30°C during the day, not exceeding 35°C at the highest; 15-30°C at night, not falling below 8°C at the lowest. Above 30°C, disease is likely; below 8°C, growth stops.
1. Field seedling raising.Generally, seedlings are raised in a solar greenhouse. The seedling tunnel should first be disinfected: for every square meter of space, use 8 g of sawdust and 480 [units] of sulfur, light the sawdust, and seal for 24 hours; this achieves disinfection and sterilization.
(1) Seedbed preparation. Seedbed soil mix: the soil used for sweet and hot pepper seedling raising is preferably sandy loam, accounting for about 60% of the total; organic fertilizer (such as livestock manure) about 30%; chemical fertilizer (such as ammonium bicarbonate, phosphate fertilizer) about 10%. After mixing the above fertilizers, spread them evenly on the seedbed, deep-plow and rake level to make beds, generally 6 m long and 1.5 m wide. Medicinal soil preparation: to sterilize and prevent disease, medicinal soil must be prepared before seedling raising and used at sowing. The main agents are: Wudai mixture (a mixture of equal amounts of 70% quintozene powder and 65% zineb powder). For each bed, mix 70-80 g of the prepared agent with 150 kg of fine soil and stir evenly for later use. This method can prevent damping-off, seedling blight, anthracnose, scab and other diseases.
(2) Variety selection. The best variety is "Zhongshu" Zhongjiao No. 7, bred by the Flower Research Institute of the Chinese Academy of Agricultural Sciences; it is a new early-maturing first-generation hybrid variety.
(3) Seed disinfection. Use 80% mancozeb (0.3% of seed weight) or 70% dexon (0.4% of seed weight). Put the seeds and the agent into a sealed wide-mouth bottle or plastic bag, seal tightly and shake continuously for 5 minutes so the powder sticks evenly to the seed coat. This can prevent early damping-off and seedling blight.
(4) Sowing. Mid-December is suitable. Half a month before sowing, cover with plastic film and straw mats to raise the indoor temperature. Sow on a sunny day. Water thoroughly the day before; the next day, spread 1/3 of the prepared medicinal soil evenly in the bed, cover with the remaining medicinal soil, or keep a small amount for filling cracks later. For every 667 sq m of land, 150 g of seed can be used.
After sowing, scatter some poison bait in the bed to trap and kill mole crickets. Pull up the straw mats at 10 a.m. every day and put them down at 3-4 p.m. In bad weather, uncover later and cover earlier. The seedlings begin to emerge in about 30 days; generally no watering is needed. If dry, spray a small amount of warm water. When the seedlings grow to 6-8 leaves, if the indoor temperature exceeds 30°C, ventilate promptly. When ventilating, do it from small to large to prevent injuring the seedlings and especially to prevent leggy growth. At planting time, the seedlings should be controlled at 9-12 leaves and 15-20 cm in height, not exceeding 25 cm. One week before planting, harden the seedlings; at night the straw mats may be left off. As long as there is no frost, do not close the ventilation openings for the last two days and nights, so the plants adapt to outside climatic conditions. In addition, when planting, damage the roots as little as possible to shorten the recovery period.
????2. Land preparation.Generally, in the autumn of the previous year, apply sufficient base fertilizer and deep-plow. Around Awakening of Insects (Jingzhe), for every 667 sq m apply 40 kg of diammonium phosphate, 20 kg of potassium sulfate, and 2 kg of zinc sulfate. To prevent continuous cropping disease, for every 667 sq m use copper sulfate with 11 kg of ammonium bicarbonate; crush each separately, mix evenly, put into an intact plastic bag, and tie the mouth tightly to seal. After 24 hours, spread evenly into the holes, then close the tunnel film and wait for planting.
????3. Planting
(1) Time. Best in late March. One week before planting, disinfect the air inside the tunnel by the same method as for disinfecting the seedling tunnel. Then ventilate to release the toxic gases.
(2) Planting. One day before planting, water the seedling bed heavily once so that roots are less damaged when pulling seedlings. Plant on a sunny day, with a spacing of 45 cm between plants and rows, two plants per hole, watering while planting; it is better to have water waiting for the seedlings than seedlings waiting for water.
(3) Management. After planting, generally do not ventilate for one week, but if the temperature exceeds 30°C, ventilation must be used to cool down. If not dry, do not water a second time; promptly straighten and fill in missing seedlings. Keep the daytime temperature between 25-30°C and the nighttime temperature between 10-15°C. When the tunnel temperature reaches above 30°C, open the ventilation openings; when it drops to 20°C, close them.
3-5 days after planting, scatter some poison bait in the tunnel to trap and kill mole crickets. When the ground is not wet, along with weeding, carry out 3-4 hoeings, from shallow to deep. Especially in low temperatures, hoeing is a powerful measure to raise soil temperature. When the seedlings grow to 30 cm, hoe deeply once to hill up the soil, and then no more hoeing. Entering March, ventilate day and night, and raise the tunnel film as much as possible, but do not remove it, to prevent damage from the last late frost. By mid-month the tunnel can be removed.
????4. Water and fertilizer management
(1) Water timely to promote flowering. From planting until the first pepper grows to about the size of a red date is the period when sweet peppers mainly undergo vegetative growth. In this period, moisture must be controlled, the soil loosened by hoeing, soil temperature raised, and root growth downward promoted; finally, hill soil around the seedlings. This stage is called the seedling-strengthening stage. Until 23 days before the first pepper flowers, water once to promote flowering, and for every 667 sq m apply 15 kg of diammonium phosphate with the water.
(2) Management during the first pepper swelling stage. When the first pepper grows to the size of a ping-pong ball, it enters the period of rapid fruit swelling; this period has relatively large water and fertilizer requirements. For every 667 sq m, apply 15 kg of urea, or 20 kg of ammonium nitrate, or 50 kg of ammonium bicarbonate with the water. Generally after another 5-6 days, irrigate once with clear water, and the first pepper then reaches harvest standard. The time is late May.
(3) Early-stage management. After the first pepper begins to be picked, the fruits on the 2nd-3rd layers begin to swell and successively reach harvest standard, and the ones above will also flower and set fruit. Up to the harvest of the 3rd layer of fruit is the early harvest period. The yield level and harvest timing of the early period have a great impact on output value.
Usually water once a week. After each harvest, apply fertilizer along with watering; following the principle of "eat small meals often," apply 7-8 kg of urea per topdressing. When there is relatively heavy rain, pay attention to drainage. Because high temperature and much rain easily cause Phytophthora blight, soft rot, and bacterial wilt, prevent them early.
(4) Mid-stage management. April 10 to July 20 is the peak harvest season for sweet peppers in medium tunnels; most of the yield and output value are determined in the mid-stage. Management in this period should grasp the following points: harvest fruit carefully, and to reduce the burden on the plants, pick immediately once the harvest standard is reached. After each fruit harvest, water once. Do not water too much; according to soil fertility and the growth of the sweet peppers, apply appropriate fertilizer with the water. If the leaf color becomes lighter and yellow, spray 5% urea or 0.3% potassium dihydrogen phosphate in the evening. Promptly control aphids, red spiders and other pests.
(5) Late-stage management. Under general conditions, sweet peppers do not easily survive the plum rain season, but with proper management they can get through it. After August 25, the weather becomes very favorable for the growth and development of sweet peppers; the plants begin to flourish, flowering increases, and the fruit-setting rate clearly rises; vegetable growers call this the "autumn flush." After the dog days, sweet peppers form a second yield peak and need watering once every 7-8 days. During the three solar terms End of Heat, White Dew, and Autumn Equinox, apply fertilizer or human manure with the water. After each topdressing, irrigate once with clear water 3-4 days later. Before Frost's Descent, pick all the fruits to avoid frost damage, then carry out autumn plowing and sun the land.