How to Grow Chilies? A Detailed Guide to Overwintering Rootstock Cultivation

Chili overwintering rootstock cultivation means using the old rootstocks of the first crop of chilies to overwinter until cultivation the following year, skipping the usual seedling-raising and sowing steps. It is simple and easy to carry out, can save more than 50% of labor, effectively prevents seedling rot and pest and disease problems, and achieves a 90% survival rate. It can bring the crop to market 40-50 days earlier, and is a practical new technique that can create high economic returns.

1. Making the overwintering bed. Choose a sandy loam soil that is sheltered from the wind and faces the sun, with deep soil, good drainage, and no previous cultivation of solanaceous crops; a pH of 5.5-7 is suitable. The bed width is 1.5 m, and the length depends on the number of plants to be grown. Build earthen ridges around the edges, with a ridge height of 60-70 cm and a width of about 20-30 cm, and dig drainage ditches around the outside of the ridges. Deeply dig the soil in the bed, break it up finely and level it, and apply sufficient base fertilizer, applying 10-15 kg of rotted barnyard manure per sq m or 30 kg of composted miscellaneous manure, mixing it thoroughly with the bed soil. Spray with 50-times-diluted formalin for disinfection, and after 15 days the chili rootstocks can be transplanted.

2. Transplanting the chili rootstocks. The period for lifting and transplanting the rootstocks is from early October to mid-November, when the chili plants begin to age. Select strong plants, cut off the crown 20-25 cm above the ground, commonly called "beheading", and keep 4-5 side branches at the base. After lifting the rootstocks, shake off the soil from the roots, handle them gently, and remove damaged and weak plants. Soak the rootstocks in a 0.1% potassium permanganate solution, then transplant them into the overwintering bed at a spacing of 8 cm × 10 cm, and cover with 8-10 cm of nutrient soil (nutrient soil mix: 60% fresh garden soil, 1 kg of NPK compound fertilizer, 40% rotted and finely crushed barnyard manure, mixed evenly). Then insert bamboo strips or wooden strips to form arches, and cover tightly with plastic film together with the bed ridges to protect the seedlings from cold and keep them warm.

3. Overwintering bed management. (1) In winter, keep the temperature inside the bed at 14-22°C. If the temperature drops on rainy or snowy days, add a covering of rice straw or thatch for insulation. Check the plastic covering regularly, and repair or re-cover it promptly if damage is found. About every 15 days, choose a sunny midday to uncover the film once for observation, and air it for 2-3 hours. If the soil surface is dry, water with a light fertilizer solution to keep the bed soil moist. (2) After the temperature rises in early spring, first remove the covering straw to let light through, and uncover the film every day at noon for ventilation for 3-5 hours, then cover it again in the afternoon. When uncovering the film, uncover the two ends first, then the two sides, and then uncover it completely. Do not uncover the film on rainy days or during cold waves and low temperatures, and continue to add grass cover for insulation, uncovering only after the temperature rises again. (3) When the chili rootstocks sprout, promptly water with a light manure solution, adding 150 g of potassium dihydrogen phosphate ammonium per bucket of manure water, and wet the bed soil to speed up the old chili rootstocks' rapid and early production of new branches and buds. Water frequently to keep it moist, pay attention to drainage, and strictly prevent waterlogging in the bed. (4) When the new buds of the chili seedlings grow to 10-15 cm, begin hardening the seedlings. First, on a cloudy day or on a sunny evening, uncover the two ends of the film for ventilation; the next evening uncover the surroundings, laying the film on top of the arches; on the third day uncover it completely and harden the seedlings for 2-3 days, after which they can be transplanted. If there are cloudy days or light rain, the film can be uncovered regardless of day or night; if the nighttime temperature is low, uncover during the day and cover at night.

4. Cultivating the overwintering rootstock seedlings. Choose new soil and deeply dig and finely level it half a month in advance. Apply 40-50 kg of NPK compound fertilizer per 667 sq m (1 mu), divide into beds and make pits according to the usual cultivation spacing, pour human and livestock manure water into the pits, cover with soil and press firm, and immediately cover with plastic mulch to prevent weeds, raise temperature, and retain moisture. Cut a round hole in the plastic mulch at the center of each pit, plant the overwintering rootstock chili seedlings, and after planting drench the pits with 1000-times-diluted zinc sulfate solution (either with clear water or dilute manure water), then cover with 1-2 cm of fine soil, which can help prevent viral disease. Soon after the overwintering rootstock seedlings survive, they will form buds and bloom, so flower and fruit fertilizer must be applied promptly, applying 10-12 kg of urea and 1500-2000 kg of human and livestock manure water per 667 sq m, and earth up around the rootstocks to prevent lodging. Pay attention to pest and disease control; other management is the same as for conventional cultivation.