Leaf rust attacks on wheat are a major problem, adversely affecting the incomes of poor farmers all over the world. A new study shows that over the past several decades, every dollar invested in CIMMYT’s wheat genetic improvement has generated at least 27 times its value in benefits to developing country farmers.

Spring bread wheat covers about two-thirds of the developing world’s wheat area, and almost 80 percent of that area was sown to CIMMYT-related semidwarf varieties in 1997. Leaf rust, caused by the fungus Puccinia triticina, is the most widespread biotic stress. The economic impact of CIMMYT’s efforts to develop leaf rust-resistant spring bread wheat varieties during 1973–97 was 5.36 billion (in 1990 adjusted US dollars) based solely on esti-mates of the value of grain farmers would have lost through use of susceptible varieties. To this conservative figure, one could add the significant economic, health, and environmental benefits of applying fewer fungicides on developing world wheat crops.

“CIMMYT investments leverage global partnerships with national research programs, advanced research institutes, an society organizations,” says Ravi P. Singh, CIMMYT wheat pathologist who leads the effort on rust research. He has successfully applied the concept of more durable, multi-gene resistance. “Rapidly mutating pathogens can overcome crop resistance based on a single gene in a few years,” Singh explains. “CIMMYT and partners have developed high-yielding and highly resistant wheats with combinations of four or five minor genes. Rust still affects the crop, but so slowly that it has little or no effect on yield.”

Global Rust Initiative

Building on strong science, partnerships, and its large collection of global wheat diversity (CIMMYT holds over 175,000 seed collections in its genebank), CIMMYT is launching a global initiative to counter the effects of a new, eastern Africa race of stem rust (Puccinia graminis) that can attack most commercial wheats in the world. Fundraising for the pioneering initiative is being led by Norman Borlaug, Nobel Peace Laureate.