Cowpea is an annual herbaceous plant of the genus Cowpea, family Leguminosae. Cowpea is available for consumption in its young pods, which are relatively nutritious and can be fried, chilled, salted, processed for pickles and dried in the sun. Because of the good heat tolerance of cowpea, it is a heat-resistant ambrosia variety.

I. Characteristics of fertility and development of cowpea

Individual development of cowpea, in terms of vining species, from sowing to pod maturity or seed maturity, can be divided into four periods, seed germination, seedling, vining and flowering and podding.

1, seed germination. Since the seed sprouting to the first pair of true leaves to carry out the process of seed germination. Cotyledons out of the ground, not photosynthesis, rely on stored nutrients in the germination decomposition of the use, to the first pair of true leaves to carry out, then photosynthesis can be carried out, independent life.

2, seedling stage. Since the first pair of true leaves to have 7 to 8 compound leaves for the seedling period. Seedling internodes are short, the stem is erect, and the root system is gradually developed. Later, the internode elongation, can not be upright and winding growth, while the base of the axillary buds began to move, it will be transferred to the vining period.

3. Vines. There are 7 to 8 compound leaves to the plant buds for the spreading period. In this period, the main vine elongates rapidly, and the base begins to draw out lateral vines from the axillary buds of the first pair of true leaves and the second to third nodes, and the rhizomes also begin to form.

4, flowering and podding period. After the plant buds to the end of the pod harvest or seed maturity, generally 5O ~ 6O days, from the single flower, the beginning of differentiation to the formation of the floral apparatus takes about 25 days, buds to flowering about 5 ~ 7 days, flowering to pod commercial maturity of about 9 ~ 13 days or so, to the pods of physiological maturity still need 4 ~ 1O days, depending on the variety and cultivation season.

Second, cowpea planting environment

1, temperature. Cowpea is resistant to high temperature and not frost. The appropriate temperature for germination is 25 to 35 degrees Celsius, the appropriate temperature for growth and development is 2O to 25 degrees Celsius, higher than 35 degrees Celsius or lower than 15 degrees Celsius, the growth of pods is affected. Close to O degrees Celsius, the plant will suffer frost damage.

2, light. Cowpea is not sensitive to the response of the length of sunshine, only a few varieties of the length of sunshine requirements are strict, suitable for growth in the short sunshine season. Generally speaking, short sunshine can accelerate growth and development and mature earlier. Cowpea likes sunlight, and during flowering and podding, if the light is insufficient, it will cause flower and pod fall.

3. Water. Cowpea is a vegetable that consumes a medium amount of water and has a strong resistance to drought. Excessive soil moisture is easy to lead to reduced germination, rotten roots and dead seedlings and drop flowers and pods, and is also unfavorable to rhizobial activity. Insufficient soil moisture will inhibit growth and development and affect yield.

4. Soil. Planting cowpea in well-drained, loose and fertile soil is ideal. The most suitable soil acidity and alkalinity is ph6.2～7. Cowpea requires nitrogen, phosphorus and potassium comprehensive fertilizer, because the rhizobium of cowpea is far less than other legumes, it should be appropriately increased nitrogen fertilizer. At the same time, the application of appropriate amount of phosphorus fertilizer can promote rhizobial activity and increase yield.

Third, cowpea planting technology

1, good seed selection: cowpea in Wuxi area spring, summer and autumn can be cultivated, long growing season, must be based on the climatic conditions of each season, choose the appropriate varieties, generally I commonly used varieties of cowpea series, Yang cowpea series, Nanjing Xingguang series, Yan belt cowpea, seven-inch cowpea, eight-inch cowpea, cowpea and so on.

2, cultivation season and sowing period: early spring cowpea in late March to early April can be sown seedlings in greenhouses and other facilities, after mid-April can be direct seeding of the ground film, after the end of April to early May can be direct seeding of the open ground. Spring and summer cowpea sowing period can be generally extended to early to mid-July. Autumn Cowpea is sown from July to early August, with seven-inch cowpea and eight-inch cowpea as the main ones.

3, land preparation for beds and basic fertilizer: cowpea is not to be cropped continuously, and needs to be rotated for more than two years, otherwise it is prone to diseases. After the harvest of the previous crop, deep plowing 2O~3O centimeters, mu apply base fertilizer 3OOO kg, calcium superphosphate 25~3O kg, grass ash or huller ash 5O~75 kg or potassium sulfate 1O~2O kg. Acidic soil can be appropriate additional lime 75 ~ 1OO kg, and then the soil broken rake flat, made into a bed width with ditch 1.3 meters of raised beds.

4, reasonable dense planting: early spring cowpea due to low temperature, rain, advocate seedling transplantation. After the seedlings come out of the ground, the first pair of true leaves should be planted when they have not yet unfolded, and the planting should master the principle of planting small, planting dry. When planting, plant two plants in each hole. Summer and fall cowpea is mostly used for direct seeding, the amount of seed sown in each hole is as little as 3 to 4 grains, and as much as 4 to 5 grains, and after the emergence of seedlings, two plants are left in each hole. Sowing density for row spacing O.8 to 1 meter, plant spacing O.26 to O.33 meters.

Cowpea planting technology

Fourth, cowpea planting field management

1, fertilizer management: the early stage should be appropriate control of water, squatting, and promote reproductive growth to form more inflorescences. Cultivated in the spring, the pre-fertilization should be appropriately controlled, to be the first - inflorescence seat pods, gradually increase the fertilizer, to promote growth, more flowers, more pods. Beginning of the pod harvest, to continuously reapply fertilizer. Fertilizer every 4 to 5 days, 3 to 4 times in a row, can be 4O to 5O kg per mu hole application of ordinary compound fertilizer or human urine 1OOO kg, watering after fertilization. Those cultivated in fall should be -promoted to the end. Mulch-covered spring cowpea, because of the developed root system, strong absorption of fertilizer, the number of times of fertilizer is less, so it is necessary to increase the basal fertilizer.

2, plant adjustment: when the vine grows to 17-3O centimeters, it is necessary to take the herringbone frame to lead the vine. When the plant grows to a certain size, it is necessary to straighten, that is, the main vine - inflorescence below the side shoots are all erased, the main vine - inflorescence above the side shoots, stay - leaf centering, in order to promote the flowering of pods. When the main vine grows to 1.3 ~ 1.7m, hit the top, so that the nutrient concentration more pods.

3, set up bracket: 5 ~ 6 true leaves should be set up bracket. Initially, the trails should be drawn up and fixed with a rope in the counterclockwise direction, usually at noon or afternoon on a sunny day. Later winding ability is very strong, without artificial assistance.

4, temperature and water management: like warmth, growth temperature 2O ~ 3O degrees Celsius, 15 degrees Celsius below the slow growth, 5 degrees Celsius below the freezing, high temperature, 35 degrees Celsius can still bloom and pods, but the quality is not good. More tolerant of drought but not flooding, the first stage should be appropriate water control, when about half of the inflorescences on the main vine began to pods, to be fully watered to ensure that the soil is moist.

5, whole branch centering: when the main vine grows the first inflorescence, the inflorescence below the lateral branches should be removed, the inflorescence above the lateral branches to be centering, the base to stay 2 leaves. When the main vine climbing full bracket when the top, to promote the lower lateral branches sprouting flower buds.

V. Cowpea harvesting and seed saving

When cowpea is harvested, be careful not to damage the rest of the flower buds, not to mention the inflorescences - all taken off. Cowpea is a successive harvesting crop and should be harvested in time before seed expansion. For cowpea, plant and fruit selection should be done when the pods are ripe. Seed plants should be centered early, in the main vine in the lower part of the third to fourth inflorescence selection of well-developed fruits to stay, to be harvested when the seed pods turn yellow and fluffy.

Six, cowpea pests and diseases control

Aphids are mainly in the seedling stage, and can spread cowpea mosaic virus disease, with 4O% of Lego sprayed once every 7 to 1O days. Bean wild borer usually occurs in large numbers during July to August (summer and fall cowpea), and harms the pods. Spray with dichlorvos 8OO times every 6~1O days during the flowering period. When there is a lot of rain in summer and fall in the south, it often causes cowpea coal mold damage. At the early stage of occurrence, 5O% carbendazim 1OOO times liquid or 5O% tolbutazin 1OOO times liquid can be sprayed 2 to 3 times to prevent and control, and cowpea rust can be used 7O% metribuzin wettable powder 1OOO times liquid or 65% diclofenac zinc 5OO times liquid. Spray every 7 to 1O days, ****2 to 3 times.