Corn Yield Tripled in Kenya

Corn yields on experimental plots in Kenya have tripled, thanks to a new weed-fighting strategy developed by the Institute's Prof. Jonathan Gressel in collaboration with Kenyan researchers Dr. Joel Ransom and Gordon Abayo.

A parasitic weed known as witchweed (Striga hermonthica) has infested 80,000 hectares (200,000 acres) of corn in Kenya, causing estimated annual losses of $10 million.

Witchweed attaches itself to the roots of a host crop. Removing it by hand or spraying it with herbicides is ineffective because by the time the weed emerges above ground it has already drained the crop.

Gressel, a member of the Plant Genetics Department, proposed using a corn genetically modified to be resistant to herbicides. Under the strategy, the corn seeds are soaked in herbicide before planting. Invading witchweed then absorbs the chemicals from the crop roots or surrounding soil and dies, while the herbicide disappears by the time the crop ripens and thus does not enter the food supply.

Kenyan researchers tested this approach for five crop seasons and found that in plots planted with herbicide soaked seeds, witchweed infestation was dramatically reduced while crop yields increased more than threefold compared with plots planted with untreated seeds.