Although the domestic price has risen to VND5,800 a kg, cassava is still exported to China in large quantities because it can fetch higher prices.
In recent years, exports to China accounted for about 5 million tonnes annually.
Vietnam has about 510,000 ha under cassava, with an annual output of nearly 9 million tonnes.
The ministry estimates the country's domestic demand for cassava this year will be 8.12 million tonnes.
Of that figure, 1.89 million tonnes are used for producing ethanol, and the remaining volume for animal feed and confectionary products.
Pham Duc Binh, deputy chairman of the Vietnam Animal Feed Association, said cassava accounted for 30-40 per cent of input materials in animal feed production.
However, cassava is also exported so domestic animal feed plants have not been able to buy enough for production, Binh told Vietnam Economic Times.
Le Khac Triet, director of the Vietnam Cassava and Cassava Starch Club, said since 2009 cassava had become an agricultural plant with high economic value.
The price of cassava has increased to VND5,700-6,000 a kg, compared to just VND200-500 a kg in 2007-08 and VND4,000 a kg in 2010.
Triet warned that cassava had become a hot product and when output exceeds demand, the price could drop as it did in 2007-08.
At that time, it would be difficult for farmers to switch to other crops because the fertility of the soil would be eroded after three to four years of growing cassava, he said.
To resolve the cassava material shortage, the cultivation area should not be increased, but measures should be taken to increase productivity, Triet said.
Farmers in some countries have harvested cassava output of 40 tonnes per ha a year while in Vietnam output is only 17.2 tonnes per ha.
Measures to increase cassava productivity include applying advanced farming techniques and finding high-yield cassava strains, he said.
He added that his club had found new cassava strains with a high yield of 40 tonnes per ha a year.
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