Efficient Early-Spring Cultivation Techniques for 'Yuejiao No. 1' Pepper in Northern Guangdong

'Yuejiao No. 1' pepper is a first-generation hybrid pepper bred by the Vegetable Research Institute of the Guangdong Academy of Agricultural Sciences. It is early-maturing, with a plant height of 65cm and a plant spread of 60cm. The fruit is thick and horn-shaped, 16-17cm long and 4cm in diameter, with a single fruit weight of 50-100g. The skin is smooth and dark green, the flesh is thick, the taste is spicy, and it is crisp and tender with excellent quality. It is resistant to phytophthora blight, bacterial wilt, and viral diseases, and yields more than 4000kg per 667 sq m. 'Yuejiao No. 1' pepper has been successfully planted in early spring for 3 consecutive years in Shixing, Lianzhou, Lechang and other places in northern Guangdong, and has been promoted over a large area.

1 Sowing and seedling raising

Based on local climatic conditions combined with @#@136@#@, early to mid-November is determined to be the most suitable sowing time. First disinfect the seeds in warm water at 55°C (keeping the temperature constant) for 15min, then soak the seeds in warm water at 20-30°C for 6-7h. Mix the seeds evenly with sifted plant ash or fine young soil, sow in the seedling bed, and be careful to sow thinly. After sowing, cover with fine crumbly topsoil, water thoroughly, and cover with plastic film. 50g of seed is needed per 667 sq m. When the seedlings grow 3-4 true leaves, move the overcrowded seedlings to sparse or empty spots to promote robust seedling growth. During the seedling stage, 1-2 additional fertilizer applications may be made as appropriate.

The main disease during the seedling stage is damping-off. On damping-off seedlings, water-soaked lesions appear at the base of the stem, quickly spread upward, and turn brown; after the diseased part loses water, it constricts into a thread-like shape, causing the seedlings to topple over. Outbreaks usually spread from a single point to a patch, and seedling collapse is rapid. After the disease occurs, choose 58% metalaxyl-mancozeb wettable powder at 500 times dilution, or Lüheng No. 1 (hymexazol) at 3000 times dilution, and spray 1-2 times depending on the severity, with an interval of 7-10 days between the two sprays. After spraying the seedbed with the pesticide, it is best to spread dry fine soil to reduce humidity and control the spread of the disease.

2 Transplanting

5-7 days before transplanting, uncover the plastic film to harden the seedlings for a period, and at the same time spray once with dimethoate at 1500 times plus chlorothalonil at 500 times to avoid transplanting with aphids. The land for planting peppers must not have solanaceous vegetables, peanuts, tobacco, etc. as the previous crop; rice is best. The base fertilizer application rate is 1500-2000kg of decomposed pig and cattle manure, 40-50kg of peanut meal, and 50kg of superphosphate per 667 sq m, applied in furrows or holes. After preparing the land, make beds running north-south, 25cm high, generally 1m including the ditch, with double-row planting and about 5500 plants per 667 sq m. Transplanting should be done on a cloudy day or on a sunny afternoon. Select vigorous seedlings and keep as much soil as possible with the seedlings to avoid root damage and increase the survival rate. After transplanting, water thoroughly to settle the roots.

3 Field management

The 10 days after transplanting are the seedling recovery stage. The focus of field management is to water thoroughly, ensure survival, and fill in gaps promptly. From 6-9 days after transplanting, apply additional fertilizer; you may apply 100g of urea dissolved in 50g of water, using 4-5kg of urea per 667 sq m, or apply decomposed human manure and urine to promote vigorous plant growth.

From 10-30 days after transplanting, the plants grow vigorously and begin to flower and set fruit. The focus of field management is to apply sufficient fertilizer and water, cultivate and earth up, and control pests and diseases. From 15-18 days after transplanting, in combination with cultivation and earthing up, apply fertilizer once, using 30-40kg of compound fertilizer and 10kg of potassium chloride per 667 sq m. In combination with fertilizing, cultivate and earth up, weed, and remove the side branches and side buds sprouting below the first fork.

One month after transplanting, attention should be paid to strengthening pest and disease control, timely harvesting, and applying sufficient water and fertilizer. 25-30 days after flowering, when the fruit has fully grown and become firm and glossy, it can be harvested. After harvesting 2-3 batches of fruit, some plants can be removed by "pulling out one every two plants" to favor the later growth of the plants.

4 Control of main pests and diseases

4.1 Phytophthora blight

Under open-field cultivation, it first damages the base of the stem, with symptoms appearing on various parts of the stem, most commonly turning brown or dark brown at the branching points. Generally, the disease tends to become epidemic when the weather suddenly clears after the rainy season or heavy rain and the temperature rises sharply. Control measures: focus on prevention, start applying pesticide from the seedling stage, and when central diseased plants appear in the field, immediately apply pesticide 2-3 times in succession. You may choose 58% metalaxyl-mancozeb wettable powder at 400-500 times dilution, or 64% oxadixyl-mancozeb wettable powder at 400-500 times dilution, or 72% mancozeb-cymoxanil wettable powder at 600 times dilution, or 69% mancozeb-dimethomorph wettable powder at 1000 times dilution, used alternately, once every 7-10 days. Spread some quicklime within 2-3m around diseased plants.

4.2 Viral disease

There are many symptoms of viral disease in pepper fields, which can be specifically divided into 4 types: ① Mosaic type: in the early stage, the veins of new leaves slightly lose green, or the leaf mesophyll shows mottling of alternating dark and light green; in severe cases, the leaf surface becomes uneven, the veins shrink, and plant growth is slow or the plant is stunted. ② Yellowing type: diseased leaves turn obviously yellow, and the plant is dwarfed. ③ Necrotic type: spots, streak spots, top necrosis, necrotic spots and other tissue necrosis appear on diseased plants and leaves. ④ Deformation: internodes shorten, the plant is dwarfed, branches and leaves cluster, and diseased leaves thicken and become smaller. That is, fern leaf. Control measures: before disease onset or in the early stage, choose 20% Virus A wettable powder at 500 times dilution, or 2% ningnanmycin aqueous solution at 500 times dilution, or 1.5% zhibingling emulsifiable concentrate at 1000 times dilution for spraying, used alternately, once every 7 days, for 3-4 consecutive sprays.

4.3 Anthracnose

This disease damages leaves and fruit. The pathogen mostly overwinters in diseased plant residues on the soil surface or attached to seeds. In warm seasons, it is easily transmitted after rain or when soil moisture is high. After leaves are affected, water-soaked spots first appear, then gradually expand and become brown, nearly round, with concentric rings. Infected fruit develop brown oval to oblong lesions, sunken, with concentric rings, and often with small black dots attached on the surface. When the disease is severe, it causes heavy defoliation and fruit rot. Control methods: drain promptly after rain and avoid water accumulation. Choose a relatively ventilated place for planting. In the early stage of disease, spray 10% difenoconazole at 1500 times dilution, 2.5% prochloraz emulsifiable concentrate at 1500 times dilution, or 50% sporgon wettable powder at 2000 times dilution, once every 5-7 days, for 2-3 consecutive applications.

4.4 Tobacco budworm

The larvae bore into and feed on flower buds, flowers, and fruit, causing flower drop, fruit drop, and fruit rot. The larval body color is generally green or bluish green in summer. Tobacco budworm eggs are mostly laid on the veins of the upper and middle leaves on both the front and back, and on the sepals and leaves of flower buds. You may choose 5% Syngenta Match emulsifiable concentrate at 1500 times dilution, or 40.7% Lorsban emulsifiable concentrate at 1000 times dilution, or 2.5% Caixi suspension concentrate at 1000 times dilution for spraying, used alternately, and spray from afternoon to evening.

4.5 Aphids

Aphids damage the undersides of leaves and tender shoots and stems. After young leaves and growing points of seedlings are damaged, the leaves curl; in severe cases, the entire leaf curls into a ball, growth stagnates, and the whole plant wilts and dies. Chemical control: choose 20% Haoniandong emulsifiable concentrate at 800 times dilution, or 10% imidacloprid wettable powder at 2000 times dilution, or 2.5% Tianwangxing at 3000 times dilution, or 50% pirimicarb at 1500 times dilution for spraying, used alternately.

4.6 Thrips

After damage, young tender leaves shrink and become deformed, branch and side-branch growth stagnates, and fruit stalks, leaves, and fruit skin turn brown. You may choose 10% Gaoxiao Dagongchen wettable powder at 1500-2000 times dilution, or 20% Haoniandong emulsifiable concentrate at 800 times dilution, or 10% imidacloprid wettable powder at 2000 times dilution for control spraying, used alternately, once every 7-10 days, for 2-3 consecutive sprays.

4.7 Mites

They damage the undersides of leaves. The damaged leaf undersides appear grayish brown or yellowish brown, with an oily sheen or oil-soaked appearance, and the leaf margins curl downward; in severe cases, defoliation, flower drop, and fruit drop occur. You may choose 73% propargite emulsifiable concentrate at 1200 times dilution, 20% fenpropathrin emulsifiable concentrate at 2000 times dilution, or 1.8% abamectin emulsifiable concentrate at 3000 times dilution for alternate spray control.