Key Technical Points for High-Efficiency Cultivation and Management of Water Spinach

Water spinach, also known as bamboo-leaf vegetable, hollow-heart vegetable, water spinach (wengcai), tongcai, or vine vegetable, is a fast-growing leafy green vegetable that has been actively introduced in various regions in recent years. Its main management techniques are as follows:

Raising Seedlings

The seed coat of water spinach is relatively thin and not hard, absorbs water quickly, and sowing dry seeds will allow them to germinate. Soaking to promote germination before sowing. For example, for every 300 sq m of greenhouse, about 2.5 kg of seeds is needed. Soak the seeds in 1/1000 thiophanate-methyl for 30 minutes, then rinse several times, and then soak in clean water for 22 hours. After removing and washing, wrap them in gauze and place them in a 30°C constant-temperature incubator to promote germination; once the seeds crack and show white, they can be sown. Before sowing, first fill small stone grains into the planting cups to 2/3 of their height, place them closely in the seedling troughs, with about 2000 cups per trough, and add clean water to the trough up to 1/3 of the planting cups. Sow 3 seeds per planting cup with the root tip pointing downward, then cover with a layer of small stone grains to slightly cover the seeds. Cover the trough surface with foam boards to maintain humidity inside the trough, and water frequently when dry. Soaking to promote germination: the seed coat of water spinach is thick and hard. If sown directly, germination will be slow due to low temperature; if there is prolonged low-temperature rainy weather, the seeds may rot. Therefore, it is advisable to promote germination by soaking the seeds in warm water at about 30°C for 18-20 hours, then wrapping them in gauze and placing them in a 30°C germination incubator. When 50%-60% of the seeds show white, they can be sown.

Preparatory Work Before Planting

1. Site selection. When selecting a site, choose a plot with sufficient sunlight and no light-blocking objects around it, and the soil should be loose and breathable, with a suitable pH value and suitable soil moisture. It must be suitable for the growth of water spinach.

2. Land preparation and bed making. Before sowing, the land needs to be prepared and beds made. We should deep-plow the soil. If conditions permit, it is best to use a rotary tiller for rotary tillage. A depth of about 10-15 cm is more appropriate. The bed height can be determined by the root depth of water spinach; a depth of about 10-15 cm is more appropriate. After leveling the soil, make beds, which should be flat beds running north-south. The width of the bed should be about 1.2 m. The bed ridge height is 0.2 m and the width is 0.3 m. To facilitate later watering and other production management, we can make a partition in the bed about every 0.3 m. Before land preparation, weeds in the land should be removed in advance to prevent weeds from competing with water spinach seeds for nutrients.

3. The method of applying base fertilizer and disinfection is to broadcast at the standard of 100 kg of lime per 667 sq m. Broadcasting should be uniform. After broadcasting, deep-plow the soil layer; the depth of plowing should be about 15-20 cm, which is more appropriate. After deep plowing, sun-dry the soil. After sun-drying for 1-2 days, sowing can be carried out.

Planting

Due to the growth of water spinach, planting should be carried out later, removing the excessively dense parts so that the water spinach can grow better. After removing them, watering and applying some organic fertilizer should be carried out to supplement nutrients.

Field Management

1. Intertillage and soil loosening, direct sowing and emergence, after transplanting or cutting survival, combined with intertillage and weeding, apply 1500-2000 kg of 2-3 parts mature human and animal manure per 666.7 sq m, and thereafter apply water once every 3-5 days.

2. Fertilizer management. About 10-15 days after sowing, when the seedlings grow to 4-6 cm, we can uncover the plastic film. If the film is not uncovered in time, it will affect the development of water spinach seedlings. It may even cause the death of the seedlings. Along with the growth of water spinach seedlings, other small grasses will also grow and compete with water spinach for nutrients. This is not conducive to the growth of water spinach. Therefore, we need to carry out intertillage and weeding. All weeds on the bed surface should be pulled out. When carrying out intertillage treatment on the bed surface, everyone should note that intertillage should not damage the plants. Otherwise, it is not conducive to plant growth. In subsequent field management, attention should also often be paid to the weed situation in the field; when weeds are seen, remove them promptly, thereby ensuring good growth of water spinach. Water spinach is a crop harvested multiple times, so in addition to applying sufficient base fertilizer, multiple split topdressings must be carried out to achieve high yield. At the seedling stage, 10%-15% dilute human feces and urine can be used for drenching, with a dosage of 1000-1500 kg per mu. When the seedlings have 3-4 true leaves, apply a mixture of 15-20 kg of compound fertilizer and 2-4 kg of urea. During the harvest period, apply 5-8 kg of compound fertilizer per mu as topdressing after each harvest.

3. Water management. Observe the dry and wet conditions of the soil. If the soil is relatively dry, watering should be carried out. When watering, the amount of water must be sufficient, and it should be watered thoroughly and soaked through, so that the soil fully absorbs water. In subsequent daily management, generally speaking, as long as the soil is seen to be relatively dry, watering can be carried out. Water spinach is a crop harvested multiple times, so in addition to applying sufficient base fertilizer, topdressing must be carried out to achieve high yield. When water spinach seedlings grow to 5-10 cm, the first topdressing can be carried out. When topdressing, it should be applied at the standard of 500-700 kg of organic fertilizer per 667 sq m. When topdressing, the fertilizer should first be diluted, and then applied along with watering. Fertilization should be uniform. Otherwise, too much fertilizer in one place will burn the plants to death. Before harvesting, generally speaking, carrying out topdressing once is sufficient.

Timely Harvesting

Timely harvesting is the key to high yield and good quality of water spinach. Generally, water spinach can be harvested when it grows to about 25-35 cm. If not harvested in time, it will both affect the eating quality of water spinach and reduce yield. Water spinach is a vegetable harvested multiple times. Generally speaking, open-field cultivated water spinach can be harvested continuously until mid-to-late August. When harvesting, all parts of the water spinach more than 4-5 cm above the ground should be harvested. Do not damage the roots of the water spinach. After water spinach is harvested, it should be tied into bundles of about 1 kg each. Because water spinach is a crop harvested multiple times, after harvesting, topdressing should also be carried out in time combined with watering. When topdressing, it should be applied at the standard of 400-500 kg of organic fertilizer per 667 sq m.

Pest and Disease Control

Water spinach has relatively few major diseases, and the main insect pests are whiteflies and others. Chlorfenapyr 1000-1500 times liquid and others can be used for spraying control. Spraying should be carried out once when water spinach grows to about 8-10 cm.