Management Methods and Technical Key Points for Small Chili Peppers in the Middle and Late Stages

I. Land preparation and basal fertilizer application: Chili peppers should not be continuously cropped with solanaceous vegetables. Choose fields with deep soil, high organic matter content, loose soil, and good drainage for planting. Chili peppers have relatively high requirements for the three major nutrient elements: nitrogen, phosphorus, and potassium. Apply 3000--4000 kg of barnyard manure per mu as basal fertilizer, plus 40 kg of compound fertilizer or phosphorus and potassium fertilizer, applied in furrows in the middle of the bed or broadcast before plowing. Build beds 1.4--1.5 m wide (including furrows), and after land preparation, cover with a plastic tunnel to store heat so as to raise the soil temperature inside the tunnel.

II. Transplanting: For early-maturing cultivation in a large plastic tunnel, transplanting is generally done in mid-to-late December each year, choosing a sunny day after cold air has passed. Plant 2 rows per bed, with a plant spacing of 25--30 cm. After transplanting, apply a root-setting fertilizer, level the bed surface, cover with plastic mulch, and set up a small arched tunnel covered with film for insulation to promote new root growth and early seedling recovery; at night, cover the small tunnel with straw bags and other coverings for insulation. III. Field management: 1. Heat preservation and cold protection. Early-maturing cultivation of chili peppers generally uses the method of a large tunnel with a small tunnel inside for cold protection, and the small tunnel film is covered with straw bags and other insulation materials. 2. Ventilation and light transmission management. Do not ventilate before the transplanted seedlings have recovered, so as to maintain relatively high temperature and humidity and promote early rooting and seedling recovery. After seedling recovery, ventilate in a timely manner; the tunnel temperature should preferably be 20--25°C during the day and 15°C at night. Regardless of sunny, cloudy, rainy, or snowy days, the small tunnel film inside the large tunnel should be removed during the day to strictly prevent insufficient light. When the nighttime temperature exceeds 15°C, ventilation can be carried out day and night. 3. Fertilizer and water management. After transplanting, water thoroughly. From March to April, temperatures are relatively low, so generally no watering is done. From late April each year to after May each year, water as appropriate according to soil moisture and plant growth conditions; where conditions permit, drip irrigation or irrigation can be used. Early-maturing cultivation of chili peppers is mainly based on basal fertilizer, with less topdressing in the early growth stage; if needed, use 0.2% urea and 0.3% compound fertilizer for foliar topdressing. In the middle and late stages, the film can be removed for topdressing; apply fertilizer once after every 2 harvests, applying 10 kg of compound fertilizer per mu each time, using hole application or strip application between plants, and cover with soil in a timely manner. After fertilizing, strengthen ventilation to prevent harm from harmful gases such as ammonia. According to soil moisture, combine topdressing with watering, or use drip irrigation with fertilizer solution. During the full fruiting stage, appropriately increase the amount of fertilizer, applying 20 kg of compound fertilizer per mu. 4. Flower and fruit preservation by flower spotting. In early spring, temperatures are relatively low, pollination and fertilization of chili peppers are poor, and flower and fruit drop is quite serious. Excessive nitrogen fertilizer application causes excessive vegetative growth, or too dense transplanting leads to insufficient light, or too high tunnel temperatures during the flowering stage. In addition to strengthening ventilation and light transmission, plant growth hormones can be used to preserve flowers and fruits, that is, from February to mid-April, use a 20X10--6 dilution of 2,4--D to spot flowers; during the full flowering stage, use 30X10--6 anti-fruit-drop hormone to spray flowers (no more than 2 times, to avoid phytotoxicity). IV. Pest and disease control. 1. Disease control. The main diseases of chili peppers include gray mold, viral disease, bacterial wilt, and anthracnose. Gray mold mainly damages young fruits, stems, and leaves. It is prone to occur in tunnel cultivation and is severe in low-temperature and rainy weather. Ventilation and light transmission should be strengthened, tunnel humidity should be reduced, and diseased leaves and fruits should be removed in a timely manner. In the early stage of the disease, Yixunling No. 2 smoke agent can be selected; for each standard 6 m X 30 m tunnel, use 1 packet (4 medicine blocks, 100 g total), fumigating once every 1 week, for a total of 2--3 times. It can also be sprayed with 800-fold dilution of 75% chlorothalonil wettable powder or 1500-fold dilution of 50% procymidone wettable powder. To control viral disease, start with agricultural control, implement crop rotation, strengthen fertilizer and water management, and promptly control aphids to reduce artificial transmission, etc. To control bacterial wilt, appropriately apply quicklime to neutralize soil acidity, promptly pull out diseased plants, and spread quicklime in planting holes and around them, etc. Anthracnose can be controlled with 1000-fold dilution of 75% thiophanate-methyl or 800-fold dilution of 75% chlorothalonil. In addition, excessively wet or dry soil, insufficient phosphate fertilizer, etc., can also cause physiological diseases such as flower drop, fruit drop, and leaf drop, so fertilizer and water management should be strengthened. 2. Pest control. Common pests of chili peppers include aphids, red spider mites, tea yellow mites, and thrips. Aphids can be controlled with 3000-fold dilution of 10% Yibianjing or 2000-fold dilution of 50% pirimicarb. When red spider mites and tea yellow mites cause severe damage, they make leaves shrivel and fruit quality decline; they can be killed by spraying with 2000-fold dilution of 73% propargite or 3000-fold dilution of 20% pyridaben. Manguangguang has good control effects on all three pests: red spider mites, tea yellow mites, and thrips. In addition, field weeds and residual branches and fallen leaves should also be removed in a timely manner to reduce pest sources.