Key Cultivation and Management Techniques for Direct Seeding of Snake Gourd in Open Fields
Snake gourd is an annual climbing vine; the stem is slender, much branched, with longitudinal ridges and grooves, covered with short pubescence and sparsely with long hirsute hairs. The snake gourd has a well-developed root system with many lateral roots and readily produces adventitious roots. The vines are slender and long, reaching 5-8 m in length. The stem is five-angled and green, with strong branching ability. The leaves are green, palmately deeply lobed, with relatively rounded sinuses, and the leaf surface has fine down. The corolla is white, and the flowers are unisexual, with male and female flowers similarly differentiated. Male flowers are mostly borne in racemes, green in the bud stage and pale yellow-green when about to open. Male flowers appear earlier than female flowers. Generally, female flowers begin to set at the 20th-25th node of the main vine, after which both the main vine and lateral vines can continuously produce female flowers. The young fruit is slender, cylindrical or curved, tapering gradually at the tip and base, shaped like a snake. The rind is grayish-white with multiple green stripes, and the flesh is white, soft and loose. The mature fruit is light reddish-brown with loose flesh. The seeds are nearly rectangular, with two parallel small grooves, a rough surface, and light brown color, with a 1000-seed weight of 200-250 g.
Environmental Requirements of Snake Gourd
1. Temperature The optimum temperature for seed germination is about 30°C, and the optimum temperature for plant growth is 20-35°C. It can still flower and set fruit normally above 35°C, but growth is slow below 20°C and stops at 15°C. It prefers warmth and tolerates heat but not cold.
2. Water Snake gourd prefers a humid environment, but due to its well-developed root system, it is also relatively drought-tolerant. In an environment with sufficient water supply and high air humidity, it sets more fruits and the fruits develop well.
3. Light Snake gourd prefers light, and the fruiting period requires relatively strong light. During the flowering period, many rainy days and low temperatures will cause flower drop and fruit abortion.
4. Soil It prefers fertile soil and tolerates fertilizer, and is also relatively tolerant of poor soil. It has wide adaptability to soil and can be cultivated in various soils, but when planted in poor land or in pots, the fruits are small and the yield is low. To obtain high quality and high yield, it should be planted in fertile places or given more base fertilizer.
Cultivation and Management of Direct Seeding of Snake Gourd in Open Fields
Cultivation Methods Snake gourd can be planted in large fields or in courtyards. In the north, it can also be intercropped with spring greenhouse tomatoes and greenhouse head lettuce, or planted sporadically in front of and behind houses. Because snake gourd has a long growth and harvest period, only one crop is planted per year. North of the Yangtze River Basin, sowing and seedling raising generally take place in March-April, and the growth period can be extended to October-November. In North China, seedlings are mostly raised in hotbeds in spring from March to April, transplanted in late April to May, and harvested from June to October.
Sowing Snake gourd is a warm-season crop with relatively strong heat tolerance but poor cold tolerance. North of the Yangtze River, sowing and seedling raising generally take place in March-April, and the growth period can be extended to October-November. It can be cultivated for the autumn off-season. If sowing and seedling raising are done earlier, insulation facilities must be added to protect against cold and preserve seedlings. Trellis cultivation is more common. Among trellis forms, flat trellis cultivation is the most common. Training Vines and Fertilizing Snake gourd is relatively tolerant of poor soil, but when planted on such land it bears few fruits and yields poorly. Therefore, during cultivation, some organic fertilizer or human manure and urine should also be applied appropriately as topdressing to promote plant growth, vigorous vines, more lateral vine sprouting, increased fruit set, and high yield. Snake gourd prefers moisture but is also drought-tolerant. Generally, when planting, if the groundwater level is not too low and the soil has a certain moisture content, there is no need to irrigate. However, to strive for a high yield, it is still necessary to irrigate 1-2 times during high temperature and drought to maintain certain soil moisture and air humidity, so as to ensure many fruits and plump fruit. Snake gourd vines grow vigorously and need timely trellising and vine guiding to expand the root system. Afterward, guide the vines onto the trellis. Before trellising, vine training should be carried out, removing lateral vines, or selecting and keeping 1-2 robust lateral vines at the base to train onto the trellis. When guiding vines onto the trellis, distribute the vines evenly so that every vine tip can receive light and dew.
Sowing and Seedling Raising Snake gourd can be directly sown in open fields, but to harvest earlier, the method of raising seedlings and transplanting should be adopted. 1) Seed treatment. Snake gourd has a thick seed coat. Before sowing, the seeds should be sun-dried for 1-2 days, then scalded with hot water at 55°C for 3 minutes. During scalding, stir constantly. After the water temperature drops, change to clean water and soak the seeds for 2-3 days. During this period, wipe off the sticky substance on the seed coat and change to clean water to continue soaking. When the seeds are slightly soft, wrap them in gauze to keep moist and place them in a 30°C constant-temperature chamber or beside a warm kang for germination. Alternatively, mix the seeds with wet sand at a 1:1 ratio, pile them together in a seedling box, and cover with a wet towel or wet gauze to keep moist. Install a 25-watt ordinary incandescent bulb under the lid of the seedling box to increase temperature, adjust the temperature to 28-30°C, and after about 4-5 days, when 80% of the seeds have sprouted, they can be sown. 2) Seedling bed or nutrient soil pot seedling raising. Nutrient soil can be made by mixing 5 parts garden soil, 2 parts peat, and 3 parts decomposed organic fertilizer. If there is no peat, spent mushroom substrate or fertile garden soil can also be used. After filling the pots, arrange them neatly and water thoroughly. Place 1 germinated seed flat in each pot and cover with fine soil 1 cm thick. Cover the seedling bed with plastic film to preserve heat and moisture. Before emergence, the temperature should preferably be maintained at 25-30°C. After emergence, remove the film according to temperature conditions, with the temperature at 25-30°C during the day and 16-18°C at night. If the temperature is still low after emergence, replace with new film with good light transmittance. When the daytime temperature meets the requirement, remove the film to allow light, or uncover both ends for ventilation, and cover again when the nighttime temperature is low. After growing two true leaves, the covering can be removed. Transplant when the seedlings have 3 leaves and 1 heart. For direct seeding in open fields, sow after germination in late April or early May with sufficient soil moisture.
3) Transplanting Before transplanting, prepare the land well and apply sufficient base fertilizer. Apply base fertilizer in furrows. Per 667 sq m, use 3000 kg of decomposed poultry and livestock manure, plus 75 kg of superphosphate and 20 kg of potassium sulfate. For sporadic planting, it is advisable to dig large planting holes, apply base fertilizer, and then transplant. For large-scale planting, the density is 80-200 cm between rows and 50-80 cm between plants, using 600-1000 seedlings per 667 sq m, depending on soil fertility, with more plants on poor soil and fewer on fertile soil. After transplanting, water thoroughly to settle the roots.
4) Harvesting Generally, harvesting for market can begin in May-June, supplying young fruits to the market. Usually, they can be harvested about 10 days after flowering. Mature fruits require more than about 30 days, at which time they can be harvested for seed saving. Mature fruits are light reddish-brown in color with loose flesh and are not edible. The seeds are nearly rectangular, with two parallel small grooves, light brown, and each fruit contains 10-50 seeds.