Detailed Explanation of Key Points of High-Yield Water Chestnut Planting Techniques

The water chestnut is the fruit of the annual herbaceous aquatic plant of the genus Trapa in the family Trapaceae, also known as water caltrop, 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 chestnut flour; the leaves can be used as green fodder or green manure. It is widely distributed in China and can be cultivated in both shallow and deep water. Let us take a look at the high-yield water chestnut planting techniques below!

Variety Selection for Water Chestnut

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

Propagation Methods for Water Chestnut

1. Direct seeding in the field: Shallow water surfaces with a depth of less than 3.3 m are mostly direct-seeded. In the Yangtze River Basin, sowing is done when water chestnut seeds sprout around Qingming. There are two sowing methods: broadcasting and drilling. For large water surfaces, drilling is preferable. First, according to the shape of the water chestnut pond, divide it into longitudinal rows with a row spacing of 2.8-3.3 m, insert poles at both ends and stretch ropes as markers, then use a boat to evenly scatter the seed water chestnuts into the water along the ropes. 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 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 irrigation and drainage as the seedling pond, and sow by dibbling with a spacing of 1 m square to raise seedlings. The seed rate is 65-90 kg per mu, which can be used for 8-10 mu of water chestnut pond. During sowing, the water depth should be controlled at 85-100 cm, and after the water chestnut seedlings emerge, the water level should be gradually increased.

Planting Techniques for Water Chestnut

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

2. Applying sufficient base fertilizer: Water chestnut has a relatively concentrated fertilizer demand. 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, 2-3 packets of strong yield enhancer or 2% potassium dihydrogen phosphate can be sprayed on the leaves 2-3 times in combination with disease and pest control.

3. Transplanting and planting: Water chestnut seedlings should be planted on the same day they are lifted. Generally, for shallow-water water chestnut, the row spacing is 1.5-2 m and the hole spacing is 1.5-2 m, with about 2-3 seedlings per hole. For deep-water water chestnut, the row spacing is 2.5-3 m and the hole spacing is 2-2.5 m, with about 8-10 seedlings per hole.

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

5. Disease and pest control: Common pests of water chestnut include aphids, leafhoppers, etc. In the early stage of damage, trichlorfon or deltamethrin can be diluted with water and sprayed for control. The common disease is mainly water chestnut blast, and in the early stage of onset, validamycin plus carbendazim can be diluted with water and sprayed for control.

6. Timely harvesting: Water chestnut matures 20-30 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 reservation, it must be harvested when fully mature. Early-maturing varieties are harvested once every 5 days, and late-maturing varieties once every 7 days.