High-yield planting techniques of cowpea

Cowpea requires high temperature and strong heat tolerance, and the suitable temperature for growth is 20-25 ℃. It can bear pods normally and does not fall flowers when the temperature is above 35 ℃ in summer, but it is not resistant to frost. When the temperature is below 10 ℃, the growth is inhibited. Cowpea belongs to short-day crops, but cowpeas cultivated as vegetables are mostly medium-light, and the sunshine requirements are not very strict, such as red-billed swallow, cowpea 28-2 and other varieties, which can be cultivated in spring, summer and autumn in the south. Cowpea has a wide adaptability to the soil, as long as the drainage is good, the soil is loose, the fields can be planted, the pods are tender, and the pod stage requires sufficient fertilizer and water.

Sowing and raising seedlings

Cowpea early-maturing cultivation generally needs strong seedlings. The sowing date should be determined according to local climatic conditions, cultivation facilities and management measures. Those cultivated in small arch greenhouse can be sown in the middle and last ten days of March, those cultivated in greenhouse can be sown in the first and middle of March, and those cultivated in greenhouse can be sown from late February to early March. In some areas, the sowing date has been delayed to late April or early May and can be broadcast live.

Before sowing, select large, full, disease-free, insect-free, non-damaged seeds, and choose sunny weather for 1-2 days, it is necessary to mix seeds with medicament and sow seeds. The seedbed should be prepared before sowing, and the thickness of the nutrient soil in the seedbed should not be less than 5 cm. The soil in the bed should be dry and wet, not too wet, otherwise it is easy to rot. When sowing, sow the seeds in the seedbed soil, cover the loose fine soil 1.5-2 cm after sowing, spread sparse straw after a little suppression, and then cover with plastic film to keep warm and moisturizing. The temperature of seedling bed was controlled at 25-30 ℃ after sowing.

Seedlings began to emerge 4-5 days after sowing, and when about 30% of the seeds were unearthed, remove the plastic film and straw in time. When most seeds emerge, the temperature of the seedling bed should be reduced to keep the temperature in the daytime at about 20 ℃, the highest temperature not more than 25 ℃, and the lowest temperature at night not less than 15 ℃. If the temperature is too high, the small arch shed can be opened to cool down, but it is necessary to prevent cold air from blowing directly into the seedbed so as not to cause freezing damage. Qimiao began to refine seedlings 4-5 days later, and during the period of seedling refining, the lowest temperature at night should not be lower than 10 ℃. Colonized when the first pair of true leaves are formed and have not yet fully unfolded. In order to protect the root system, nutrition bowl can be used to raise seedlings under certain conditions.

Soil preparation and application of base fertilizer

Cowpea is not tolerant to waterlogging, and the growing period is long, so it needs more nutrients during the growth period, so we should choose the soil with high dry terrain, deep soil layer, rich organic matter and convenient drainage and irrigation. Apply basic fertilizer 10-15 days before planting, generally apply fully mature human feces and urine or chicken and duck manure 1500-2000 kg, calcium superphosphate 15-20 kg, plant ash 75-100kg, ditch application can also be applied. After soil preparation, the width of the border is 100-110 cm, the width of the groove is 40 cm, and the height of the border is 20-25 cm. Smooth the border and cover with plastic film.

Colonization

Although the root system of cowpea is developed, the regeneration ability of root system is weak, so it is suitable to transplant seedlings. Generally, when the cotyledons are unfolded and the first pair of true leaves are not fully unfolded, the colonization can be delayed when the seedlings are raised in a nutrient bowl. Planting should be carried out on a sunny day with a cold tail and a warm head, pour water through the seedling bed before planting, and then raise seedlings to eliminate abnormal seedlings such as cotyledon defect and true leaf distortion. Cowpea was planted in two rows with a distance of 24-27 cm and 2-3 plants per hole. The opening of plastic film should be small when planting, pour some root water immediately after planting, and then seal it with soil.

Management after planting

1. Replenish seedlings

It should be checked in time after planting, and the seedlings with missing seedlings or damaged basal leaves should be replenished in time. After replenishing seedlings, water should be poured in time to ensure that these seedlings can grow synchronously with other normal seedlings.

2. Water management

After the cowpea is returned to the seedling, the moisture should be strictly controlled before flowering and podding, otherwise it will cause overgrowth, flowering node rise, lateral bud germination, easy to cause the middle and lower part of the plant empty vine (no pods). Generally, the seedlings will be watered every 3-5 days after planting, and will not be watered in principle after that. If there is too much water in the early flowering stage, the plant will grow too much and consume too much nutrients, so that the buds can not get enough nutrients and lead to the drop of flowers and pods. After setting pods, the plants grow vigorously, not only grow stems and leaves, but also blossom and bear pods one after another, and the water demand increases, so it is necessary to supply more water to promote the elongation and expansion of pods, increase the number of pods, and maintain the better growth of the plant. In general, young pods are watered when they are 2-3 cm, and then watered every 5-7 days, but to prevent waterlogging after rain.

3. Topdressing

The principle of cowpea topdressing is "less application before flowering, more application after flowering, and re-application at podding stage". Generally, after the seedling survived, the seedling fertilizer was applied once, and the mature human feces and urine of 15% MUE 20% per mu was applied to 1000 kg. After flowering, 1500 kg of mature human urine was applied with 20% concentration. After podding, 2000 kg of mature human feces and urine and 10 kg of superphosphate were applied after podding, and then every other week, or 15 kg of compound fertilizer per mu. In the later stage of cowpea growth, cowpea can be re-applied 2-3 times and compound fertilizer 15-20 kg each time to promote plant vigorous growth, continue to shoot inflorescence, increase pod setting rate, prolong harvest time and increase yield.

4. Build a fight in time

Generally speaking, the plant should set up a frame to draw the vine when it begins to "shake the vine" to prevent it from intertwining with each other, so as to facilitate ventilation and light transmission, and reduce the drop of flowers and pods. Generally, a bamboo pole with a length of 2-2.5 meters is put into the word frame, and one is inserted into each hole. The bamboo pole is inserted into the soil at a distance of 10-15 cm from the base of the plant. A bamboo pole is placed at the intersection of the upper and middle parts of the plant, and the cross beam is fastened with a rope. After setting up the frame, the vine is drawn counterclockwise for 2-3 times to make the plant stem grow along the support, and then let it grow naturally. The bamboo pole used in cowpea scaffolding is longer, so it should be operated carefully so as not to break the greenhouse film at the top of the bamboo pole. After setting up the frame, especially after entering the harvest period, the old and diseased leaves at the base should be removed in time according to the growth of the plant.

Pest control

The common diseases of cowpea are rust, gray mold, Sclerotinia sclerotiorum and anthracnose. The main pests are aphids, bean pod borer, thrips and so on. Measures should be taken to control them in time.

Harvest

Cowpea reached the initial harvest period 40-50 days after planting. Generally speaking, cowpeas reach commercial maturity about 10-12 days after flowering, and can be harvested one after another. the specific harvest standard is that the pods are full, showing the inherent color of the variety, but not yet "drum beans". If the harvest is too early, the yield is low, if the harvest is too late, the pods are easy to aging, and the cowpea falls seriously, so the harvest should be more timely.