India plans to impose an extra 5% tax on vegetable oil imports within weeks and use the revenue to help boost the country's stagnating oilseed production, two government sources said. India is the world's biggest importer of vegetable oils, buying nearly $10 billion worth a year, its biggest import after crude oil and gold. The country's consumption of vegetable oils - including palm oil and soyoil - has trebled over the last 20 years as the population grew and incomes rose, while output has increased by less than a third. Now, the government plans to create an oilseed fund by imposing the 5% surcharge, or cess, that will be used to help Indian farmers step up oilseed production, said the sources, who did not wish to be identified in line with government policy.