Although the drought-caused famine of 198485 in Ethiopia remains well known, the country has suffered less serious but significant droughts in 1987, 1988, 1991-92, 1993-94, 1999, and 2002. When drought hits, all crops fail except one—grass pea (Lathyrus sativus). The survival of the poor, therefore, depends on this crop. While harmless to humans in small quantities, a steady diet of grass pea seeds over about a three-month period can cause a neurological disorder that frequently results in irreversible paralysis of the leg muscles. This is because the grass pea seeds, although tasty and rich in protein, contain a neurotoxin called R-N-oxalyl-L-a-B diaminopropionic acid (B-ODAP). The disorder caused by this neurotoxin has several names, including paraparesis, lathyrism, and neurolathyrism. Under certain conditions, eating grass pea can lead to retardation and death in young children. The African grass pea types contain 0.7% or more of this neurotoxin, much higher than the safe levels (below 0.2%) for human consumption.

Thousands of people who frequently confront drought and crop failures in Ethiopia face permanent paralysis of the legs from eating grass pea. The poor people know the effects of eating grass pea but live under such desperate conditions that they have no other option but to eat it.

A legume crop—part of the family to which peas and beans belong—grass pea is also grown in Bangladesh, China, India, Nepal, and Pakistan. It is similar in appearance to mung bean, with small green seed. Researchers at ICARDA recently harvested the first grass pea lines that can be eaten without fear of paralysis. This was accomplished by crossing grass pea from the Middle East—many of which have naturally low toxin levels (average about 0.1%)--with African and Asian varieties. The new ICARDA hybrids contain between 0.02% and 0.04% of neurotoxin, and are perfectly safe for human consumption.

To accomplish that objective, the scientists used a technique known as somaclonal variation to force the plant to mutate and to express genes that were formerly dormant. Among these dormant genes were the genetic codes that controlled the plant's neurotoxins. ICARDA's improved grass pea lines produce 1.5 tons of seed per hectare even with less than 200 mm (8 inches) of rainfall.