As a war of words rages over biofuels and their impact on world food supplies, researchers in India are promoting sweet sorghum as a crop that combines the best of both worlds. The plants, which grow three metres high in dry conditions, yield grain that can be eaten by people or animals; their stalks provide sweet juice for bioethanol production and a crushed residue that can be burnt or fed to cattle.

Scientists at India's National Research Centre for Sorghum and the International Crops Research Institute for the Semi-Arid Tropics near Hyderabad announced this week that they had developed new varieties of sweet sorghum, which could provide sugary juice for year-round fermentation and distillation into ethanol. The first sorghum bioethanol plant began operations last year in Andhra Pradesh and more plants will be built in collaboration with Tata Chemical.

Sweet sorghum - so called because its stalks contain more sugary sap than the closely related grain sorghum - has traditionally been grown mainly for animal feed but the latest high-yielding varieties produce good quality grain too.