Detailed Explanation of Key Technical Points for Growing Green Beans in Greenhouses

Growing green beans in greenhouses mainly includes: variety selection, seedling raising, transplanting, field management, pest and disease control, harvesting and other important technical steps.

Green Bean Growing Techniques in Greenhouses

1. Variety Selection

Early-maturing, high-quality and high-yielding varieties should be selected; the main varieties are: Purple Flower Oil Bean, Peanut Material Oil Bean, and Hacai Bean No. 1.

2. Seedling Raising

Seedlings are raised in nutrient pots inside a greenhouse. The sowing period is generally early to mid-March in southern regions and mid-to-late March in northern regions. Standard for strong seedlings: well-hardened strong seedlings with short but sturdy plant clumps, a well-developed root system, 2—3 true leaves, and a seedling age of 30—35 days.

3. Transplanting

Transplanting is generally done in early to mid-April. Insulation measures at transplanting: for internal insulation, build small tunnels inside the greenhouse and hang double-layer screens; when necessary, use a warm-air stove inside the greenhouse; for external insulation, mainly cover the surrounding area of the greenhouse with straw mats.

4. Field Management

Maintain 20-25°C during the day and 15—20°C at night; during the flowering stage, keep it around 20°C during the day and above 15°C at night to facilitate normal flowering and pod setting. In terms of water management, because the common bean has a certain drought tolerance, generally no irrigation or fertilization is carried out from transplanting to before flowering, to prevent excessive vegetative growth of stems and leaves. When flowering begins, increase ventilation to remove humid air, which helps pollination, avoids flower drop, and reduces diseases.

5. Harvesting and Marketing

The edible part of the common bean is the tender pod; when the pods reach market maturity, they should be harvested in a timely manner. Generally, dwarf varieties begin harvesting 25-35 days after transplanting, and climbing varieties begin harvesting 35—45 days after transplanting, with harvests every 3—5 days, and once every 1—2 days during the peak pod-setting period. Harvesting too late affects quality and pod setting of subsequent inflorescences; harvested pods should be marketed promptly, and those not yet marketed can be kept fresh at 3°C.