How to Grow Water Caltrop for High Yield? Latest Planting Techniques and Methods Tutorial

Water caltrop is the fruit of the annual herbaceous aquatic plant water caltrop of the genus Trapa in the family Trapaceae, also known as water chestnut, dragon horn, water chestnut, etc.; when young and tender it can be eaten raw as a fruit, when fully ripe the fruit can be eaten cooked or processed into water caltrop flour, and the leaves can be used as green fodder or green manure; it is widely distributed in China and can be cultivated in shallow water as well as planted in deep water. Let us take a look together at the high-yield cultivation techniques for water caltrop!

Variety Selection for Water Caltrop

For water caltrop, varieties that are high quality, high yielding, disease resistant and suited to the market should be selected according to the water depth of the cultivation site and local consumption habits. If it is mainly for raw consumption, early and mid-season varieties with large fruits (two-horned water caltrop) can be chosen, and placed on the market in batches at different times. If high yield is the main goal, late-maturing black water caltrop varieties can be planted. Water surfaces with a water depth of 0.3 to 1.5 m are suitable for planting shallow-water water caltrop varieties, and water surfaces with a water depth of 2 to 4 m are suitable for planting deep-water water caltrop varieties.

Propagation Methods for Water Caltrop

1. Direct seeding in the field: shallow water surfaces with a water depth of less than 3.3 m are mostly direct seeded; in the Yangtze River basin, sowing is done when the water caltrop seeds sprout at Qingming. There are two sowing methods: broadcast sowing and drill sowing. For large water surfaces, drill sowing is preferable. First, according to the shape of the water caltrop pond, divide it into longitudinal rows with a row spacing of 2.8 to 3.3 m, insert poles at both ends and stretch ropes as markers, then use a boat to evenly scatter the seed water caltrop into the water along the rope lines. The sowing amount and density vary depending on the variety and water surface conditions.

2. Seedling raising and transplanting: when the water depth is above 3.3 m, direct seeding makes seedling emergence difficult, the sprouts are thin and weak, and the yield is low, so seedling raising and transplanting are necessary. In the Yangtze River basin, from Chunfen to Qingming, select a pond sheltered from the wind, with relatively shallow water, fertile soil and convenient drainage and irrigation as the seedling pond, and sow the seeds in hills at a spacing of 1 m square to raise seedlings. The seed rate is 65 to 90 kg per mu, which can supply 8 to 10 mu of water caltrop pond. During sowing, the water depth should be controlled at 85 to 100 cm, and after the water caltrop seedlings emerge, the water level should be gradually raised.

Cultivation Techniques for Water Caltrop

1. Selection of water caltrop pond: for water caltrop cultivation, it is advisable to choose ponds, river bends, low-lying water surfaces, lake edges, etc. with a water depth of 0.3 to 4 m, fertile soil, relatively small wind and waves, and gentle rise and fall. It is preferable that the underwater silt layer is more than 20 cm deep and the soil organic matter content is above 1.5%.

2. Applying sufficient base fertilizer: water caltrop has a relatively concentrated demand for fertilizer. Before planting, 2000 kg of pig manure or decomposed mud manure can be applied per mu. After germination, 5 kg of urea per mu can be applied as a quick-acting fertilizer. After flowering, in 2 to 3 applications combined with disease and pest control, 2 to 3 packets of strong yield-increasing agent or 2% potassium dihydrogen phosphate can be used for foliar spraying.

3. Transplanting and planting: water caltrop seedlings should be lifted and planted on the same day. Generally, for shallow-water water caltrop, the row spacing is 1.5 to 2 m and the hill spacing is 1.5 to 2 m, with about 2 to 3 seedlings planted per hill as one bundle. For deep-water water caltrop, the row spacing is 2.5 to 3 m and the hill spacing is 2 to 2.5 m, with about 8 to 10 seedlings planted per hill as one bundle.

4. Timely weeding: there are many kinds of aquatic weeds in water caltrop ponds, such as duckweed, centipede grass, moss, etc., which must be removed manually in time, otherwise they will affect the photosynthesis of water caltrop. Generally, weeds are removed once every 10 days after transplanting until the water caltrop covers the water surface.

5. Pest and disease control: common pests of water caltrop include aphids, leafhoppers, etc., which can be controlled in the early stage of damage by spraying trichlorfon or decis mixed with water. The common disease is mainly water caltrop blast, which can be controlled in the early stage of onset by spraying validamycin plus carbendazim mixed with water.

6. Timely harvesting: water caltrop matures 20 to 30 days after flowering. For use as a vegetable or for raw eating, it should be harvested when the sepals have fallen off and the fruit skin has not yet fully hardened. For cooked eating, processing or seed preservation, it must be harvested when fully mature. Early-maturing varieties are harvested once every 5 days, and late-maturing varieties once every 7 days.