Clean potatoes have helped enrich the lives of local farmers," said Nguyen Phung Hoan, director of Nam Dinh’s seedling centre.

Since 2005, the year the province joined a German-sponsored programme to increase potato yields, the area under cultivation has increased 10 fold.

Nam Dinh’s Science and Technology Department has set up a seedling laboratory to provide disease-free potatoes to farmers. The province has also built a storehouse capable of holding 1,500 tonnes of the root vegetables and passed on new technologies to farmers. In 2006, Nam Dinh’s seedling centre provided potato seeds to 20 co-operatives at 75 per cent the price of imported germs.

Productivity has also been high; farmers can reap in the neighbourhood of 20 tonnes per ha, a 20-25 per cent increase over previous levels. The price of potatoes has also jumped from VND500 to VND800 per kilogram.

"Since we began growing potatoes without disease, we have harvested eight to nine tonnes per 360 sq.m, which makes us VND1 million," said farmer Nguyen Thi Loan from Vu Ban District. Her last crop sold out quickly, she said.

The drive has received financial support from the German Technical Co-operation (GTZ) and aims to increase potato production across Viet Nam to 50,000 ha by 2010. The project will encourage small households to embrace the tuber.

"The potato cultivation area in Viet Nam is 35,000 ha with an average productivity of 13 to 15 tonnes per ha, but this can reach 24 or 25 tonnes per ha," said Nguyen Chi Ngoc, head of Viet Nam’s Cultivation Department.

According to officials and farmers, potato growing is about three times as lucrative as growing rice. The root vegetables also leave the land soft, which is good for growing peanuts.

German and Vietnamese officials believe potato cultivation could provide jobs for 50,000 household in the Hong (Red) River Delta