Eleocharis dulcis

The crop can be cultivated in paddies (2-7.5 m wide by up to 100 m long to allow for mechanization)[15] or in a hydroponic culture.[16] As it is an aquatic plant, it should always be submerged in approximately 10 cm of water.[6] The crop needs continuously high soil temperatures, ideally 14-15.5 °C.[6] At 13.6 °C, the corms begin to sprout.[15] Soil is ideally a sandy loam with pH 6.5 to 7.2.[17] The plant produces two types of subterranean rhizomes. Under long-daylength conditions, rhizomes grow horizontally and then turn upwards forming daughter plants. Under short-daylength conditions, the rhizomes grow downward and produce a corm at the tip.[6][15] The photoperiod also significantly influences how fast the corms grow. Corms begin to develop much more slowly if the photoperiod exceeds 12 hours.[18] The corms are also the propagating material.[15] Alternatively, transplants can be used.[16] Machinery such as tractor-mounted vegetable planters can be used for plantation.[15]

Nitrogen addition is beneficial for corm production, applying a dose before planting and another dose when corms begin to enlarge.[15] To further improve nutrient levels, potassium and phosphorus mineral fertilizers can be used before planting, where the N:P:K uptake ratio is 1.00:0.50:1.75.[15] Also organic mulch, especially mushroom compost, shows good results.[15]

Once the corms turn dark brown, they should be harvested.[15] If left in the soil after this point in time, corms will get sweeter, however shelf life will decline.[15] The corms can be harvested using a modified gladioli corm harvester once the paddy is drained.[16] Alternatively, a "water-suction harvester" can be used without the need to drain the paddy.[15] The corms have to be washed after harvest and brushed once they are dry.[16]

The per plant yield was described at 2.3 kg/season (fresh matter).[9] In China, yields are reported between 20-40t/ha,[6] while in the United States a range between 47-85 t/ha has been mentioned.[9]

The harvested corms are best stored at 4 °C. At this temperature, transpiration and thus weight loss are minimized.[15] This will also delay sprouting and minimize deterioration resulting from small injuries.[15] Corms should not be stored at temperatures above 13.6 °C as otherwise the corms will begin to sprout.[15] If the corms need to be stored longer term, they can also be kept in a solution of 1000 ppm sodium hypochlorite.[19]

Chinese water chestnut is usually not very prone to pests;[16] nevertheless, some animals and fungi may attack the plant: Water fowl may damage the stems and corms, especially when plants are young.[15] Similarly, rodents and grazing animals pose a threat to the Chinese water chestnut, which may be discouraged by keeping the paddy inundated.[15] Fly larvae (Trichoptera sp.) and other leaf-eating caterpillars also feed on the stems. However, unless complete defoliation below the waterline occurs, the plants can normally tolerate this damage.[15] Plant hoppers (Fulgoridae) and scale insects feed on plant sap and may cause subsequent death.[15] Other pests represent nematodes Ditylenchus spp. and Dolichodorus heterocephalus.[6] Fungal species can also attack the Chinese water chestnut. In warmer climates, a rust is caused by Uromyces[15] and Cylindrosporium eleocharidis is causing stem blight.[20]