Planting technique of cowpea

Cowpea, also known as long bean, long bean, bean, carob bean, rice bean, kidney bean, belt bean, undress bean, chopstick bean, belongs to the annual herb of cowpea of Leguminosae. Cowpeas are eaten with tender pods, which are rich in nutrition, such as stir-frying, salting, processing kimchi and drying dried beans. Because of the good heat resistance of cowpea, it is a heat-resistant variety. The following editor will introduce the planting technology of cowpea.

Characteristics of growth and development of cowpea

The ontogeny of cowpea can be divided into four stages: from sowing to pod maturity or seed maturity, seed germination stage, seedling stage, vine stage and flowering and pod stage.

1. Seed germination period. The process from seed germination to the development of the first pair of true leaves is the seed germination stage. Cotyledons unearthed, do not carry out photosynthesis, rely on stored nutrients in the germination of decomposition and use, to the first pair of real leaves to carry out photosynthesis, independent life.

2. Seedling stage. The seedling stage is from the development of the first pair of true leaves to having 7-8 compound leaves. In the seedling stage, the internodes were short, the stem was erect, and the root system developed gradually. After that, the internodes elongated and could not grow upright and twined. At the same time, the basal axillary buds began to move and then turned to the trailing stage.

3. Ripening period. There are 7 to 8 compound leaves in the stage of trailing from bud appearance of the plant. During this period, the main vine elongated rapidly, the base began to draw out lateral vines in the first pair of true leaves and axillary buds of nodes 2 ~ 3, and root nodules began to form.

4. Flowering and podding stage. It takes about 25 days from bud appearance to pod harvest or seed maturity, about 25 days from differentiation to floral organ formation, 5 to 7 days from budding to flowering, 9 to 13 days from flowering to commercial maturity of pods, and 4 days to physiological maturity of pods, which varies according to varieties and cultivation seasons.

Planting environment of cowpea

1. Temperature. Cowpea is resistant to high temperature and not resistant to frost. The optimum temperature for germination was 25-35 ℃, and the optimum temperature for growth and development was 20-25 ℃, which was higher than 35 ℃ or lower than 15 ℃. When the plant is close to 0 ℃, the plant will be damaged by freezing.

2. Light. Cowpea is not sensitive to the length of sunshine, and only a few varieties are strict with the length of sunshine, which is suitable for growing in short-day season. Generally speaking, short-day exposure can accelerate growth and development and mature earlier. Cowpeas like the sun, during flowering and podding, if there is not enough light, it will cause flowers and pods to fall.

3. Moisture. Cowpea is a vegetable with moderate water consumption and has strong drought resistance. Too much soil moisture can easily lead to the decrease of germination rate, rotting roots, dead seedlings and falling flowers and pods, which is not conducive to the activity of rhizobium. Insufficient soil moisture will inhibit growth and development and affect yield.

4. Soil. Planting cowpea with good drainage, loose and fertile soil is the most ideal. The most suitable soil pH is PH6.2~7. Cowpea requires comprehensive fertilizer of nitrogen, phosphorus and potassium. Because the rhizobia of cowpea are far inferior to other legume plants, nitrogen fertilizer should be applied appropriately. At the same time, the application of appropriate amount of phosphate fertilizer can promote the activity of rhizobium and increase the yield.

Planting techniques of cowpea

1. Selection of improved varieties: cowpea can be cultivated in spring, summer and autumn in Wuxi area, and the growing season is long. Suitable varieties must be selected according to the climatic conditions of each season. Generally speaking, my commonly used varieties are cowpea series, cowpea series, Nanjing starlight series, swallow cowpea, seven-inch cowpea, eight-inch cowpea, cowpea and so on.

2. Cultivation season and sowing date: cowpea in early spring can be sown and raised seedlings in greenhouse and other facilities from late March to early April, direct seeding with plastic film after mid-April, and open-field direct seeding from the end of April to early May. The sowing time of cowpea in spring and summer can be extended to the first and middle of July. Autumn cowpeas are sown from July to early August, mainly seven-inch cowpea and eight-inch cowpea.

3. Land preparation and application of basic fertilizer: cowpea should not be cropped continuously and should be rotated for more than two years, otherwise diseases are easy to occur. After harvest, the former crop was ploughed 20 cm deep, 3000 kg per mu of base fertilizer, 25 kg of superphosphate, 50 kg of plant ash or rice chaff ash or 10 kg of potassium sulfate. Acid soil can be properly added with lime 75-100 kg, and then the soil will be broken and raked flat to form a high border with a width of 1.3 meters.

4. Reasonable close planting: cowpea in early spring is encouraged to raise seedlings and transplant because of its low temperature and more Rain Water. After the seedlings are unearthed, the first pair of true leaves should be planted before they are unfolded, and the principles of planting small and dry should be grasped. Two plants were planted in each hole when planting. Cowpea in summer and autumn mostly used direct seeding. The sowing amount of cowpea in each hole was as little as 3-4 grains, and as many as 4-5 seeds. After emergence, there were up to 2 plants in each hole. The sowing density is 0.81m between rows and 0.26mm between plants.

Field management of cowpea planting

1. Fertilizer and water management: in the early stage, it is necessary to properly control moisture, squat seedlings and promote reproductive growth so as to form more inflorescences. When cultivated in spring, fertilizer and water should be properly controlled in the early stage. After setting pods in the first inflorescence, fertilizer and water should be gradually increased to promote growth, more flowering and more pods. At the beginning of a good harvest of pods, it is necessary to apply topdressing continuously. Topdressing once every 4-5 days, 3-4 times in a row, 40-50 kg of common compound fertilizer or 1000 kg of human feces and urine can be applied per mu and watered after fertilization. Those cultivated in autumn should be promoted to the end. For the spring cowpea covered with plastic film, it is necessary to apply more base fertilizer because of its developed root system, strong fertilizer absorption and less times of topdressing.

2. Plant adjustment: when the vine grows to 170cm, it is necessary to build a herringbone frame to draw the vine. When the plant grows to a certain size, it needs to be pruned, that is, all the lateral buds below the first inflorescence of the main vine are erased, and the lateral branches above the first inflorescence of the main vine, leaving a leaf to pick the heart, in order to promote flowering and pod formation. When the main vine grows to 1.3m and 1.7m, it will top, so that the nutrients will concentrate and bear more pods.

3. Setting up stents: when 5 or 6 true leaves are set up, stents should be set up. At the initial stage, the vine should be pulled on the shelf in a counterclockwise direction and fixed with a rope, usually at noon or afternoon on a sunny day; in the later stage, the winding ability is very strong and there is no need for manual assistance.

4. Temperature and water management: like warmth, the suitable temperature for growth is 20: 30 ℃, the growth is slow below 15 ℃, freezing injury occurs below 5 ℃, and it can bear high temperature. It can still blossom and bear pods at 35 ℃, but the quality is poor. It is more resistant to drought but not resistant to waterlogging, and the early stage should be properly controlled. When about half of the inflorescences on the main vine begin to bear pods, they should be fully watered to ensure that the soil is moist.

5. pruning and heart-picking: when the main vine grows the first inflorescence, all the lateral branches below the inflorescence should be removed, and the lateral branches above the inflorescence should be removed, leaving 2 leaves at the base; when the main vine climbs all over the support, hit the top to promote the lower side branches to sprout flower buds.

Harvest and seed retention of cowpea

When harvesting cowpeas, be careful not to damage the rest of the flower buds, let alone pick off the inflorescences together. Cowpeas are harvested one after another, and should be harvested in time before the seeds expand. Leave the cowpea, plant selection and fruit selection when the pod is ripe. The seeds should be heart-picked as early as possible, and the well-developed fruits should be selected from the third to fourth inflorescences in the middle and lower part of the main vine, and the seeds should be harvested when the pods turn yellow and soft.

Control of diseases and insect pests of cowpea

Aphids are mainly harmful at the seedling stage and can spread cowpea mosaic virus disease. 40% dimethoate is sprayed every 7 to 10 days. Wild bean borer generally occurs in large numbers from July to August (summer and autumn cowpea), harming pods. Spraying dichlorvos at flowering stage every 6 to 10 days, Rain Water often causes cowpea coal mildew damage in summer and autumn in the south. At the initial stage of occurrence, 50% carbendazim 1000 times or 50% topiramate 1000 times spray 2 times 3 times, while cowpea rust can be treated with 1000 times methyl topiramate wettable powder or 65% Dysen zinc 1000 times. Spray once every 7-10 days, a total of 2-3 times.