AMSTERDAM – In the Mekong Delta, farmers obtain 6-7 tons of rice per hectare in dry seasons and 4-5 tons per hectare in wet seasons, using fast-maturing rice varieties that allow up to three consecutive yields annually. By contrast, West African rice farmers harvest only 1.5 tons per hectare of traditional upland rice annually, while other cereals yield no more than one ton – a figure comparable to yields in medieval Europe.