When the bell rang at midday, students fetched tin bowls and lined up under trees in the schoolyard for scoops of corn and bean porridge. Not one of them was fussy about the food.

After the rainy seasons shortchanged Engaruka, a Maasai village in northern Tanzania, children suffered too many days when there was no porridge — no food at all to eat in their mud-and-stick huts. Drought is to blame for a good share of their suffering.

Scientists are developing drought-tolerant corn, which could ease hunger across Tanzania and other parts of sub-Saharan Africa. But the corn can't be planted in most places because it was genetically modified.