DHAKA, Bangladesh: Potatoes are not traditionally high on the menu for the 140 million people in Bangladesh, but a surge in rice and wheat prices has prompted the government to popularize the humble spud as a substitute food. "Think potato, grow potato and eat potato," was the main slogan of a three-day potato festival in Dhaka last week. Bangladesh's government is waging a campaign to convince millions of Bangladeshis to embrace potatoes as a staple food because of record high rice and wheat prices and an unusually good crop of potatoes that will need to be eaten quickly before they rot. Since grain prices soared, about a third of Bangladeshis have had to skip one or two meals a day because they could not afford to buy rice, which forms the bulk of their diet. One kilogram of rice, or 2.2 pounds, has doubled in price over the past year and now costs 40 taka, about 58 cents, almost half the daily wage of a factory worker. Wheat costs 44 taka for a kilogram, up 150 percent. By contrast, a kilogram of potatoes sells for 13 taka in the capital, and far less in the countryside. Potatoes are native to Latin America, but sometime in the 18th century they were brought from Europe to South Asia, where they are mostly eaten as a vegetable ingredient in dishes like curry. Although an excellent carbohydrate substitute to rice, it is hard to persuade Asians, who often do not regard a meal to be complete without a bowl of rice, to switch. "It's not possible to change people's food habit overnight," said Nazrul Islam, director of Bangladesh's Agriculture Information Service. "Potato cannot replace rice as the main staple, but I think they will soon realize it can be a very good substitute at a reasonably low cost." Potatoes are regarded as a safe crop in Bangladesh because they are planted in October and harvested by the end of February, when the land is dry and before annual floods ravage the country, leaving thousands of people homeless and hungry. Potatoes are now Bangladesh's biggest crop after rice. Consumption has risen from an average of 7 kilograms per capita in 1991 to 24 kilograms in 2007, according to agriculture officials. Potato consumption in Britain is about 114 kilograms per capita, and in Belarus, the world's biggest potato consumer, it is around 338 kilograms per capita, according to the International Year of the Potato Web site. Bangladesh's government, which recently ordered 500,000 troops to eat potatoes, hopes potato consumption will jump drastically in the coming years as experts say it is unlikely rice prices will return back to previous lows. "We grow potato every year as a subsidiary crop, along with pulses and spices," said Mariam, a village farmer near Dhaka, who added that farmers "will have to rely on potato as a principal crop in the future." "Growing wheat is difficult as it needs more fertilizer and irrigation," Mariam said. "Potato is easier and cheaper to grow." Experts see potatoes as a potential antidote to hunger caused by higher food prices, a global population that is growing by one billion each decade, climbing costs for fertilizer and reduced cropland. The potato has been called a "hidden treasure" by the United Nations, which proclaimed 2008 as the International Year of the Potato. Asian countries are seeing potatoes as their possible salvation as they scramble to feed their people at reasonable prices in the future in a region where the population is estimated to soar by some 35 percent to 4.9 billion by 2025. Food security is vital in the region, as many governments fear unrest if food staple prices keep going up. India has said it wants to double potato production in the next 5 to 10 years. China, a huge rice consumer, has become the top potato grower in the world. In sub-Saharan Africa, the potato is expanding more than any other crop right now. Potatoes are an excellent source of complex carbohydrates, which release their energy slowly, and they have only 5 percent of the fat content of wheat. When boiled, potatoes have more protein than corn and nearly twice the calcium, according to the Potato Center in Peru. They are also rich in vitamins, iron, potassium and zinc. "Rice and potato contain almost similar quantity of calories," said S.K. Roy, a nutrition expert in Dhaka. But potatoes "are rich in vitamin C and other food values. So nutritionally, potato can be a real good substitute for rice." This year, Bangladesh produced its biggest potato crop ever, more than eight million tons, three million tons more than last year. But the country lacks warehouses to store the potatoes, which spoil easily, and officials fear much of the stock will go to waste even as people starve or suffer from malnutrition because they cannot afford rice and refuse to turn to potatoes. "We cannot let the potatoes, which provide us a strong food backing in this period when food grains are short in supply and high in prices, rot and perish," the army chief, General Moeen Ahmed, told the crowd at the potato festival. "So let us all take more potato and make it a viable substitute for other foods." Officials say Bangladesh can preserve only 2.2 million tons of potatoes in 300 existing cold-storage facilities across the country. "It means we will have about three million tons left," said Harunur Rashid, managing director of Canteen Stores Department, a supermarket chain run by the army that organized the Dhaka potato festival in a bid to popularize potatoes among the masses. "This is huge; we have to consume it," he said.