13 Technical Points for Growing Peppers in Greenhouses, a Must-Read for Pepper Growers
Since greenhouse pepper technology became widespread, people can enjoy fresh peppers in any season, and the growing market has remained stable. Below are 13 technical points for growing peppers in greenhouses, for everyone's reference.
1. Seed treatment
Before sowing, soak the pepper seeds in a 10% trisodium phosphate solution for 30 minutes. To prevent anthracnose and bacterial spot disease, first pre-soak them in clean water for 5-6 hours, then soak them in a copper sulfate solution for 5 minutes, then rinse them clean with water before sprouting. When sprouting, wrap the treated seeds in a damp cloth and place them at 20-23 degrees C; after 24 hours raise the temperature to 25-34 degrees C; once the sprouts show white, lower the temperature again to 20-25 degrees C to harden the sprouts; once 50% of the seeds have sprouted white, sow them.
2. Sowing and raising seedlings
Because heated seedling raising gives a high emergence rate and fast growth, the sowing rate should be lower than for cold-frame seedling raising. After sowing, cover with about 0.5 cm of nutrient soil, then cover the soil with a layer of rice straw, then a layer of plastic film, and finally cover with a small arched shed sealed for insulation. After sowing, heat day and night, keeping the temperature at 22-24 degrees C. When 40% of the seeds have emerged, remove the straw covering the soil and the film on the straw to prevent the seedlings from becoming leggy. After the seedlings emerge evenly, pay attention to ventilation and cooling.
3. Reasonable watering
Peppers grown in greenhouses are prone to drying out in the hotbed, so water should be replenished frequently. Too little watering cannot meet the needs of seedling growth, while too much watering creates high humidity, which easily causes pepper seedlings to become leggy and leads to damping-off and other diseases. The humidity of the seedbed soil should be kept so that the surface soil turns white while the subsoil stays moist.
4. Controlling leggy growth
If the bed temperature becomes too high and the seedlings become leggy, the most effective measure is to check the bed temperature frequently and control the temperature. Hotbed seedling raising takes a short time, so sufficient base fertilizer should be applied in the nutrient soil, and generally no topdressing is needed. If the seedlings are rather small and thin, you can spray 99% monopotassium phosphate 2-3 times for foliar topdressing. If the nutrient soil is too dry, water at noon on a sunny day, and the amount of water should not be too large.
5. Timely seedling separation
When the seedlings grow 2 true leaves, separate them once, transplanting the seedlings into nutrient pots, 1 plant per pot. Before separating, harden the seedlings at low temperature for 2-3 days, and water to lift the seedlings 1-2 days before separating. Plant the separated seedlings shallowly, with the cotyledons exposed above the soil surface, and water promptly after planting. After separating, close the shed tightly, maintaining a daytime temperature of 25-30 degrees C and a nighttime temperature of 16-18 degrees C. After the seedlings recover, maintain a daytime temperature of 20-25 degrees C and a nighttime temperature of 14-16 degrees C. Do not water unless there is no transpiration; when dry, water lightly. Water once 1 week before planting, and 2 days later lift the seedlings and harden them to promote rooting and recovery.
6. Land preparation and fertilization
Peppers can be planted on flat beds or in ridges. For the convenience of mulching and watering, as well as to help raise soil temperature, ridge planting in a north-south direction is recommended. When ridge planting, the ridge spacing must vary by variety, and the row and plant spacing should be determined according to the plant spread angle of the variety used. For the winter-spring crop, the dense planting method of wide and narrow rows with two plants per hole is often suitable. The wide row spacing is 55-60 cm, and the narrow row spacing is 40-50 cm. When fertilizing, first spread the organic fertilizer on the ground, deep plow twice to mix the fertilizer thoroughly with the soil, then open furrows according to the row spacing, apply cake fertilizer and chemical fertilizer in the furrows, and after thoroughly mixing with the soil, build ridges over the furrows, with a ridge height of 15-20 cm.
7. Scientific planting
The planting time for greenhouse peppers is late January. Planting must be done on a sunny day, and it is hoped that after planting there will be several consecutive sunny days. This requires listening to and watching the weather forecast more. Planting should preferably be done in the morning. When planting, open holes at a hole spacing of about 33 cm. Plant about 4,000 holes per mu, with 2 plants per hole, totaling 8,000 plants per mu, aiming for early yield through dense planting. The 2 plants in the same hole should be uniform in size. When planting the seedlings, pour warm water (30-40 degrees C) into the hole to place the seedlings, and close the hole after the water seeps down.
8. Temperature management
After planting greenhouse peppers, in order to promote seedling recovery, early-spring cultivation should be kept closed and insulated, maintaining no ventilation for 5-6 days and keeping a high-temperature, high-humidity environment. Do not ventilate during the day and cover with straw mats appropriately early so as to maintain a relatively high temperature at night. After the seedlings recover, maintain the daytime temperature at 26-28 degrees C, and ventilate to cool down when it exceeds 30 degrees C.
9. Humidity management
The suitable relative air humidity for pepper growth is 60-80%, and the suitable relative soil moisture is about 80%. Too high humidity easily causes the plants to become leggy, affecting the dispersal of pollen grains and thereby affecting pollination and fertilization. Under the condition of ensuring a certain temperature, ventilate boldly to reduce the humidity inside the shed.
10. Ventilation management
The suitable temperature for peppers during flowering and fruit setting is 20-25 degrees C. At this time, increase the ventilation volume and ventilation time. Ventilation can reduce humidity, increase light, promote sturdy and compact plant growth with short and numerous internodes, and also help pepper flowering and pollination, resulting in more fruit and ensuring early maturity and high yield. Generally, during the flowering and fruit-setting period of peppers, control the nighttime temperature to not be lower than 15 degrees C, and ventilate day and night without affecting flowering and fertilization.
11. Light management
In winter, light intensity is low. While ensuring the greenhouse temperature, extend the lighting time as much as possible, uncover straw mats early and cover them late, so that the plants receive more light. At the same time, keep the film surface clean to improve light transmission. On the north side of the greenhouse, reflective screens can be hung to increase light intensity. On cloudy or snowy days, light intensity is low and plant respiration consumes a lot, so foliar topdressing can be carried out by spraying 1% sugar water.
12. Water and fertilizer management
When enough water has been given at planting, generally do not water until the first fruit sets. During the seedling hardening period after recovery, focus on cultivating and loosening the soil, and the soil below the plastic mulch can remain moist with good aeration. At the end of seedling hardening, water once. At this time, the first pepper has grown to about 3 cm in diameter. Apply Tiannongsu (20% wood vinegar + trace elements) or Genmate (50% wood vinegar + trace elements) with the water per mu. After that, apply fertilizer with every watering or every second watering.
13. Plant adjustment
When cultivating greenhouse peppers, pruning should be carried out to promote fruiting. The method is that when the young fruit borne on the secondary lateral branch of the main lateral branch grows to 1 cm in diameter, leave 5 leaves above it and pinch off the growing tip, so that nutrients are concentrated on supplying fruit growth. Leggy branches that appear in the middle and later stages should be removed promptly.
In addition, when related pests and diseases appear in greenhouse peppers, effective control measures should be taken promptly, as delayed control can cause irreparable losses.