A disease that damages wheat has taken root in West Bengal, forcing the state government to ban cultivation in two districts bordering Bangladesh for two years, and anywhere else 5 km from the border. Wheat blast, caused by a fungus, causes ripe wheat to turn whitish and dry up. It can infect large areas in a short time and render an area infertile for two to three years. Once it strikes, the entire field of standing crops has to be burnt and the ash disposed to prevent a return the next season. First identified in Brazil in 1985, it struck last year in Bangladesh, where crops over 20,000 hectares were burnt.