Water caltrop, a type of plant that swims well, bears fruit called tubers, which are sweet and delicious. People in Vinh Long sell them for more profit than growing rice.

Farmers in Tan Hanh commune (Long Ho district, Vinh Long province) are starting the dry season harvest (off-season crop) with prices more than double compared to the flood season crop (favourable crop).

Ms. Nguyen Thi Lan (56 years old, in Tan Hiep hamlet), who is selling water chestnuts along National Highway 1 (Vinh Long City bypass) said that water chestnut farmers in the commune have been harvesting water chestnuts during the dry season for about a month now.

Currently, the price of fresh water chestnuts (fresh water chestnuts) grade 1 that traders buy at the field is 13,000 VND/kg, an increase of 1,000-2,000 VND/kg compared to the same period last year and more than double the price of water chestnuts harvested in September-November of the previous lunar year; and fresh water chestnuts grade 2 (water chestnuts are worse than grade 1) are 10,000 VND/kg.

Traders weigh the fresh water chestnuts for her at 15,000-16,000 VND/kg; she boils the water chestnuts, puts them in bags and sells them to customers for 30,000 VND/kg.

Ms. Lan also informed that the price of water chestnuts will gradually increase from now until the end of the dry season this year; last year, at the end of the off-season, water chestnut farmers sold the tubers in the field at 22,000-23,000 VND/kg of fresh water chestnuts.

The model of growing water caltrops in rice fields and interspersed with garden ditches has existed in Tan Hanh commune for many years now, with the area of ​​water caltrops growing around 15 hectares per year. Previously, farmers only grew water caltrops during the flood season.

But recently, water chestnuts are grown year-round, concentrated in the hamlets of Tan Thuan, Tan Nhon, Tan An and Tan Hiep.

There is only one type of water chestnut chosen for planting, the Taiwanese water chestnut variety, because this water chestnut variety has high yield and is easy to grow.

Farmers are harvesting water chestnuts grown in Tan Thuan hamlet, Tan Hanh commune (Long Ho district, Vinh Long province).

Although not a crop with high economic value, growing water caltrop has been bringing in a regular source of income, helping people here stabilize their lives.

Water caltrop growers have also gradually improved their growing methods to achieve the highest efficiency; that is, they use thin plastic sheets to keep water in the caltrop fields from being lost.

Planting water caltrops with straight lines and planting at a lower density will help the caltrops hatch quickly, grow evenly, save effort in pest control and keep the caltrops from withering for a long time.

According to farmers' calculations, on the same field, farmers can grow a maximum of 3 crops of young larva each year, most commonly 5 crops/2 years.

Each water chestnut crop only lasts 4-5 months, from planting to harvesting all the fruits (tubers), the water chestnuts will wither and must be removed to plant a new crop.

After about 3 months of planting, the water chestnut can be harvested. Each crop of water chestnuts is harvested 2-3 times, with a total yield of 1-1.2 tons/acre/crop.

Compared to rice cultivation, the labor and investment costs for growing water chestnuts are the same, but the profit from growing water chestnuts is 2-2.5 times higher. In recent years, the price of water chestnuts (water chestnuts) has been quite high, from 6,000-7,000 VND/kg for water chestnuts grown in the favorable season and from 12,000-13,000 VND/kg for water chestnuts grown in the unfavorable season.

After deducting costs (fertilizers, pesticides, and hiring workers to pick the fruit), growers still make a profit of 5-7 million VND/ha/crop. The consumption of water chestnuts is also favorable, with traders coming to the fields to buy, and farmers do not have to worry about output.