How to Grow Hyacinth Beans for High Yield? A Detailed Guide to Standardized Cultivation Techniques
Hyacinth bean, Lablab purpureus (Linn.) Sweet, commonly known as bian dou, also called fire-sickle hyacinth bean, vine bean, hedge bean, magpie bean, cha bean, moon vegetable, belongs to the Dicotyledoneae class. There are also many varieties, such as: white hyacinth bean, purple hyacinth bean, oil bean, snake bean, pig's ear bean (shaped like a pig's ear). It is a perennial, twining vine plant of the genus Lablab in the Fabaceae family. It is a legume plant. It is cultivated in tropical and subtropical regions throughout the world. Hyacinth bean flowers come in red and white, and the pods come in colors such as green-white, light green, pink or purple-red. The young pods are eaten as a vegetable, while the white flowers and white seeds are used medicinally, helping to dispel summer-dampness pathogenic factors, with effects of strengthening the spleen and stopping diarrhea; at the same time, hyacinth bean also has a notable effect in reducing tumors.
Plant morphology of hyacinth bean
Annual twining herb. Leaflets 3; terminal leaflet rhombic-broadly ovate, lateral leaflets obliquely rhombic-broadly ovate, 10 cm long, 4.5-10.5 cm wide, apex shortly acute or gradually acute, base broadly cuneate or nearly truncate, both surfaces with white short pubescence along the veins. Racemes axillary; flowers 2-4 clustered on the nodes of the rachis; upper 2 teeth of the calyx almost completely connate, the remaining 3 teeth nearly equal; corolla white or purple-red, the standard petal with 2 appendages on both sides at the base; ovary silky-hairy, with glands at the base, style with white beard hairs near the apex. Pods flat, sickle-shaped or semi-elliptical, 5-7 cm long; seeds 3-5, flat, oblong, white or purple-black. Flowering and fruiting period July-September.
Growth habits
Perennial, twining vine. The whole plant is almost hairless, the stem can reach 6 m long, often light purple. Pinnately compound leaves with 3 leaflets; stipules basifixed, lanceolate; stipels linear, 3-4 mm long; leaflets broadly triangular-ovate, 6-10 cm long, width about equal to length, lateral leaflets unequal on both sides, oblique, apex acutely acute or gradually acute, base nearly truncate. The suitable germination temperature for seeds is 22-23°C. The plant can tolerate high temperatures of around 35°C, has a well-developed and strong root system, strong drought tolerance, and good adaptability to various soils; planting in well-drained and fertile sandy soil or loam can significantly increase yield. Annual herbaceous plant, stems trailing, leaflets lanceolate, flowers white or purple, pods oblong, flat, slightly curved. Seeds white or purple-black. Prefers warmth and moisture, tolerates heat. Generally sown in spring and harvested in autumn. The young pods are an ordinary vegetable, and the seeds can be used medicinally.
Standardized high-yield cultivation techniques for hyacinth bean
Variety selection
For hyacinth bean cultivation, it is advisable to choose white-seeded varieties that tolerate low temperatures, grow quickly, bear many pods early, have young pods with little fiber, are crisp and tasty, have strong stress resistance, and are marketable, such as Shanghai white hyacinth bean, Chongming white hyacinth bean and Chunbian No. 1, etc.
Land preparation and ridging, appropriate application of base fertilizer
Plow the soil and sun the field 5-7 days before sowing. When sowing, prepare the land and make ridges, with a bed width of 100 cm, bed height of 10-15 cm, and ditch width of 50 cm. Open shallow holes according to the sowing density specifications and apply base fertilizer. Apply 15 kg per mu of sulfur-containing ternary compound fertilizer as base fertilizer in the sowing holes, then mix the fertilizer evenly with the topsoil and wait for sowing.
Sowing at the right time, rational close planting
For open-field cultivation, the suitable sowing period is early to mid-April, with a sowing rate of 3.5-4 kg per mu. Small arched shed seedling raising and transplanting can also be used, and its sowing period can be 10-15 days earlier than open-field cultivation. The sowing density is preferably 1500-2000 holes per mu. Sowing method: sow 2 rows per bed, with a row spacing of 50 cm and a hole spacing of 50 cm, sow 3 seeds per hole, cover with about 3 cm of soil, thin and fill in seedlings after emergence, leaving 2 plants per hole, and leaving 3000-4000 plants per mu.
Fertilization management
Fertilization principles: apply base fertilizer appropriately, apply good fertilizer for promoting vines, and apply heavy fertilizer for promoting buds. During the seedling stage, apply 2 applications of vine-promoting fertilizer. The first time is within 15 days after emergence, combined with intertillage and weeding, broadcast 10 kg per mu of sulfur-containing ternary compound fertilizer, or 5 kg of urea plus 5 kg of potassium sulfate, and apply with water. The second time is when the seedlings are about 20 cm tall, apply 1500 kg per mu of barn manure, or 1000 kg of fresh leaves or fresh tender grass, combined with earthing up. White-seeded hyacinth bean has a long harvest period. At the beginning of harvest, apply 1 heavy application of quick-acting nitrogen fertilizer to promote the occurrence and growth of new buds; 7-10 kg of urea per mu can be applied, broadcast on rainy days to avoid fertilizer injury. Afterward, according to growth conditions, apply 1-2 foliar topdressings combined with pest control, or spray the quick-acting organic micro-fertilizer Xiaoyedi at 800 times dilution during the flowering and podding stages to increase the podding rate.
Trellising and pruning
When the hyacinth bean plants grow to about 40 cm, begin trellising. Insert 1 miscellaneous wood pole or small bamboo pole 200 cm long per hole, and at a height of 150 cm tie 4 miscellaneous wood poles together in a bird's nest shape, and guide the vines onto the trellis. When the main vine grows to about 150 cm, begin pinching the growing tip to promote the occurrence of side branches and vine extension. When the side vines twine to the top of the trellis, also pinch the growing tip to promote the development of the lower inflorescences and the occurrence of secondary vines on the side vines. In the middle and late podding stages, promptly remove old yellow leaves in the middle and lower parts, and thin out some leaves where stems and leaves are too dense and remove late-growing tender buds to improve light transmission conditions.
Pest and disease control
During the growth period of hyacinth bean, attention should be paid to controlling pests such as aphids, red spiders, bean pod borers and tobacco cutworms. From the beginning of the flowering stage, attention should be paid to the control of bean pod borers. Starting from the bud stage of each inflorescence, spray once every 7-10 days to ensure normal flowering and podding. Pesticides can be selected from 1% sophocarpidine at 800 times, 1.1% Lülang at 1000 times, 2.5% Decis at 1500 times, Shi'an at 500-800 times, 5% Yitaibao at 1000 times, and 2.5% cyhalothrin at 2000 times for spraying control.
The main diseases of hyacinth bean include damping-off, seedling blight, anthracnose and gray mold, etc., which can be controlled by selecting 50% carbendazim or 50% thiophanate-methyl at 600 times dilution, and 50% iprodione at 800-1000 times dilution.
Timely harvest
Hyacinth bean is eaten for its young pods and young seeds, and should be harvested in batches at the right time. Harvesting too young results in small seeds and low yield; harvesting too old affects marketability. It can be harvested when the pods appear light green and the seeds are swollen and plump. Generally, the first season's harvest period is from early to mid-July to mid-August, and the second season's harvest period is from early September to late October. The yield per mu can reach more than 1500 kg.