From Revolution to Evolution: The Continuing Impacts of International Wheat Breeding

In the late 1960s, spectacular achievements in wheat breeding contributed to a ,"Green Revolution" in South Asia. Since then, some may wonder what wheat breeding research has done for the world lately.

A new CIMMYT study confirms that, during the last two decades, payoffs to wheat research by a global network of scientists have been as high as during the heady years of the Green Revolution.

The study, "Impacts of International Wheat Breeding Research in the Developing World, 1966-1990," finds that developing country farmers who used new varieties of spring bread wheat between 1977 and 1990 harvested--in 1990 alone--an extra 15.5 million tons of grain, worth about US$ 3 billion at 1990 prices.

During the 1980s, an additional 16 million hectares in the developing world--mostly unirrigated--were sown to new wheat varieties, equaling the area--mostly irrigated--brought under improved wheats during the Green Revolution. Most farmers who experienced the first wave of the wheat revolution have replaced their Green Revolution varieties with newer strains of wheat at least twice.

Using these newer varieties, farmers raised their yields by about 1% every year. The superior disease resistance of the newer wheats has also paid off. In the large areas throughout the world where farmers grow spring bread wheat under irrigation, resistance to one disease alone--leaf rust--is worth about US$ 150 million each year. And because this resistance is built into the genetic structure of CIMMYT wheats, the need for environmentally hazardous chemicals to control disease outbreaks has been dramatically reduced.

Even more important, however, is that for poor farmers--who can rarely afford to apply chemicals anyway--this built in genetic resistance will help ensure higher and more stable yields well into the future.

CIMMYT has played a vital role in this success. "Varieties with CIMMYT ancestry now cover more than 50 million hectares in the developing world," observes Derek Byerlee, CIMMYT economist and one of the authors of the study. "That's impressive, cc nsidering that the total area sown to wheat in developing countries outside of China is but 70 million hectares--about three times the size of the US wheat-growing area."

More important than the numbers, though, is knowing whether that research has helped the people who need it most.

"While it's better to look at this issue for individual countries than at the global level," says Byerlee, "we estimate that more than 50% of the benefits of international wheat research have been captured by farmers and consumers in South Asia, which is where about half of the world's poor people live."

Having accomplished so much lately, what can we expect from wheat research in the future? The study cautions that sustaining the rate of gains from research will require both vision and perseverance. Improved wheats have yet to make an impact in some areas, usually characterized by extreme drought, fierce heat, or excessive cold. Expansion into these areas will probably be slow and the gains modest. Even in more benign environments yield gains may be harder to secure. All the more reason, concludes the CIMMYT study, to ensure sustained investment in research on more efficient, ingenious ways to maintain progress.

(CIMMYT news release)