Detailed Explanation of Asparagus Bean Planting Methods and Technical Points

Asparagus bean, also called cowpea, is a vegetable abundantly produced in summer. It belongs to the cultivated species within the cowpea species that can form long pods, and is an annual twining herbaceous plant.

Planting Methods

I. Variety and Soil Selection  

For autumn asparagus bean planting, choose varieties with strong cold resistance, strong moisture resistance, and strong re-flowering ability. For the soil, sandy loam with higher terrain, deep soil layers, good drainage, moderate pH, and that has not previously grown legume crops is best.  

II. Timely Sowing, Reasonable Close Planting  Autumn asparagus beans should be sown in August to September. Direct sowing is preferable. For reasonable close planting, use 1.25 to 1.5 kg of seed per mu, with row spacing of 50 to 60 cm and plant spacing of 8 to 10 cm, in double rows, sowing 2 seeds per hole.  

III. Field Management  

1. Inserting bamboo and guiding vines: Generally, when the seedlings grow to 30 to 40 cm, insert bamboo and guide the vines. Vine guiding should be done in cool weather on sunny days, and it is best to guide about 4 vines per bamboo stake.  

2. Fertilizer and water management: Asparagus bean fertilization should be mainly base fertilizer, supplemented by topdressing. For the base fertilizer, apply 1500 to 2000 kg of high-quality farmyard manure and 20 kg of compound fertilizer when forming the beds, and at the early flowering stage, when earthing up, apply 30 to 40 kg of Xingwang fruit-and-vegetable compound fertilizer on both sides of the bed. Topdressing at the seedling stage should be light and dilute, gradually increasing the fertilization concentration as the plant grows, and each topdressing should be done on a sunny day. During the harvest period, supplement topdressing as appropriate according to growth conditions.  

Asparagus beans dislike moisture throughout the entire growth period. Excessively wet soil can easily cause excessive vegetative growth or root rot. This is especially true if the soil is too wet after sowing, as the seeds absorb too much water and sprout too early and too quickly, making the seedling tissues tender, weakening stress resistance, and easily causing excessive growth or seedling death. Therefore, sowing should be done on sunny days, and before sowing, the sowing rows should be thoroughly watered first, then sown, and no watering should be done within 2 to 3 days after sowing. When the seeds begin to emerge, water moderately, which helps the seedlings grow robustly. During flowering and pod setting, the water requirement is greater, especially in autumn when temperatures are high and evaporation is large, so water in the early morning and evening to regulate the field microclimate.  

IV. Pest and Disease Control  

The main diseases of asparagus beans are root rot and rust. For root rot, follow the principle of "prevention first, combining prevention and control" through crop rotation and field management. At the same time, when sowing, mix 1 kg of 50% carbendazim with 400 to 500 kg of fine soil and cover the seeds with it. In the early stage of disease, drench the roots with a 200 to 300 times dilution of 37% root rot remedy or a 1000 to 1500 times dilution of dexon, once every 3 to 5 days, for 2 to 3 consecutive times. For rust, spray with a 200 to 250 times dilution of colloidal sulfur, or use 150 to 200 g of 15% triadimefon wettable powder mixed with 75 to 80 kg of water. The main insect pests are the bean pod borer and the cowpea pod borer. Use a 500 times dilution of 25% dimehypo aqueous solution or 50 to 75 g of Cascade mixed with 60 kg of water, spraying once every 7 to 10 days from bud appearance to the early flowering stage, for 2 to 3 consecutive times.

First, apply an appropriate amount of nitrogen fertilizer in the early growth stage. At the seedling stage of common beans, the nitrogen-fixing ability of the root nodules is weak, so applying an appropriate amount of nitrogen fertilizer can promote early vine development and robust growth. However, if the plant grows vigorously, nitrogen fertilizer must be controlled or not used, to prevent excessive vegetative growth, commonly called crazy growth, which can delay the flowering period, cause flower and fruit drop, or delay fruiting.

The first topdressing should be timed at the bud appearance stage of the first inflorescence, applying 10 kg of urea per mu or an appropriate amount of manure. When the pods grow to 3-4 cm long, that is, from the flowering and fruiting stage onward, begin continuous topdressing. Depending on the different crop seasons and plant growth conditions, generally topdress once every 10-20 days.

Manure and compound fertilizer should be used alternately, with an appropriate amount of manure and 10-20 kg of compound fertilizer per mu.

Topdressing is best applied with irrigation water, which helps dissolution. Between two topdressings, water once with clear water to promote photosynthesis and meet the needs of rapid pod growth. In addition to root fertilization, foliar fertilizer can also be sprayed on the leaves, with fairly obvious results.