When should cowpeas be planted and how should field management be done to achieve high yields?

Cowpeas are rich in vitamin B, vitamin C and plant protein, can calm the mind, regulate the digestive system, and relieve chest and diaphragm distension. They have a relatively stable sales market, so what are the high-yield cowpea planting techniques? When is the planting time? How should field management be done for high yields?

1. When is the cowpea planting time?

Cowpeas are divided into spring cowpeas, summer cowpeas and autumn cowpeas according to different planting times.

1. Spring cowpeas are generally raised as seedlings from late February to late March, planted out from late March to late April, harvested from early June to mid-August, and seed-collected from late July to early August.

2. Summer cowpeas are sown in the Yellow River basin from April 20 to June 30, in the Yangtze River basin from mid-April to early July, in northern Guangxi from early April to early August, in Zhejiang and Fujian in spring and summer, and in the Leizhou Peninsula in spring.

3. Autumn cowpeas should be sown in August-September.

2. How should field management be done after planting cowpeas for high yields?

1. Seedling stage management

Two days after sowing, lightly sprinkle water according to the dry or wet condition of the ridge surface to ensure the moisture needed for emergence. After 5 to 6 days, when the bean seedlings have two leaves and one heart, drench once with 800 times junduqing plus 300 times jinggangmycin, using 750 kg of liquid per mu, to prevent and control root rot, blight and other diseases. Thin the seedlings in time to ensure one plant every 20 cm. When applying chemicals, be careful that the granules do not touch the plants. Apply fertilizer appropriately according to the growth of the bean seedlings: use 3 to 5 kg of urea per mu, add an equal amount of potassium fertilizer, mix with 1000 to 1500 kg of water, and sprinkle lightly with water after application.

Controlling bean thrips is the key point at the seedling stage. Bean thrips damage the young tender growing tips, which is also the common condition of no shoot emerging and only two leaves being seen, commonly known as “blind heart”. To control bean thrips, use 600 times isocarbophos plus 600 times yisaoli, or 1500 times abamectin plus 1500 times imidacloprid, or 500 times haoniandong plus 1500 times 5% fipronil, spraying once every 6 days, and spray 1 to 2 times with yunda 120 at the seedling stage.

2. Vine growth stage management

When the bean seedlings begin to send out vines, carry out heavy hilling, combined with fertilization: use 30 kg of phosphate fertilizer per mu plus 10 kg of urea, apply evenly on both sides of the ridge, and cover the fertilizer and weeds with soil from the furrow, being careful that the fertilizer and soil do not touch the bean stems. If conditions permit, apply 2000 kg of barnyard manure per mu and hill soil along the ridge sides. After hilling, drench once with a sulfur-amine mixture, using 1 kg of copper sulfate and 2 kg of ammonium bicarbonate per mu plus 1000 kg of water.

At the same time, train the vines onto supports, generally using an A-frame trellis. If the seedlings grow vigorously, a conical trellis can be used, that is, every 40 cm, insert three bamboo poles into an equilateral triangle, tie them with rope into a cone away from the ridge surface, and put horizontal bamboo on top; to make operation easier, the trellis height should be controlled within 2 m. A conical trellis can increase yield by more than 10% compared with an A-frame trellis. Control moisture: on sunny days irrigate with running water once every 3 days, while wetting the ridge surface, and pay attention to drainage on rainy days.

Diseases and insect pests during the vine growth stage are mainly rust, powdery mildew, bean thrips and bean pod borer. Use triadimefon (800 to 500 times) plus 500 times isocarbophos plus 800 times anlubao, or 600 times xiansheng plus 600 times wannengfen plus 800 times yisaoli. Note that the concentration of triadimefon should go from dilute to concentrated (800 to 500 times), spray once every 7 days, and add yunda 120 every 14 days.

3. Harvest stage management

About 60 days after sowing, the plants enter reproductive growth and the harvest stage begins. Fertilize once every 7 days, each time using 10 kg of compound fertilizer per mu plus 5 kg of urea, mix with 100 kg of manure and compost for 3 days, add 1500 kg of water and apply to the ridge surface, then sprinkle lightly with water; or apply in holes along the ridge sides, using 20 kg of compound fertilizer per mu plus 10 kg of potassium fertilizer plus 10 kg of urea, opening small holes every 35 cm along the ridge sides and applying, applying to one side of each ridge, then after 10 days apply the same amount of fertilizer to the other side. Before hole application, water sufficiently, and do not water the ridge surface within two days after application; do not fertilize on rainy days. During the harvest stage, keep 1 to 2 cm of water in the furrow.

For disease and pest control, the following agents can be selected. For Septoria leaf spot and blight: 600 times 75% chlorothalonil plus 600 times 70% mancozeb; for rust and powdery mildew: 300 times 50% colloidal sulfur, drenching 1000 kg of liquid per mu, but the premise is that no symptoms have appeared yet, as prevention is better than cure. The main insect pest is bean pod borer, and the following can be used:

1. 1000 times caixi plus 1500 times imidacloprid;

2. 1500 times abamectin plus 600 times anlubao;

3. 1000 times Bacillus thuringiensis plus 800 times xiaochongdi. The above 3 agents should not be mixed with fungicides.

Because bean pod borer control is very difficult, spraying should be done once every 3 to 4 days, and spraying before 10 a.m. when the bean flowers are open gives a better effect. Add yunda 120 every 7 days. Harvesting in the morning before the dew has dried is preferable.