A new wheat variety that yields a whopping 18 tons per hectare was announced this month at a conference in New Delhi held by Mexico's International Wheat and Maize Improvement Center (CIMMYT). The advance could dramatically boost world wheat production, although experts worry that the fertilizer-hungry plant might worsen pollution from crop runoffs.
Earful. CIMMYT's supergrain.
CIMMYT
Wheat production around the world now averages 2.7 tons per hectare, although some varieties can yield up to 12 tons, according to CIMMYT director Timothy Reeves. Any further gains, he says, have been stymied by the plant's basic architecture. But now the "yield barrier" has been broken by a sturdy new large-eared breed that CIMMYT researchers have spent almost 20 years developing. "The plant has a robust small stem and three times as much grain-bearing capacity" as old high-yield varieties--that is, it holds up to 200 grains per stalk, says CIMMYT wheat researcher Sanjaya Rajaram. The yet-unnamed breed combines many traits, including branching capability from Polonicum wheat and hardiness from wild goat grass. What's more, says Reeves, "the whole plumbing system of the plant had to be overhauled so that it could partition more resources into grain" as opposed to stalk.
But some experts worry that the new wheat may not be practical. "How are you going to feed the plant? Does it mean massive inputs of chemical fertilizers?" asks geneticist M. S. Swaminathan, director of the M. S. Swaminathan Research Foundation in Chennai (formerly Madras). Indeed, in the first trials in Chile, the 18-ton yield was achieved under optimal conditions and with extremely intense fertilizer use. Because wheat generally needs 25 kg of fertilizer per ton of yield, this breed requires 400 kg per hectare.
CIMMYT says they are working on a technology called "bed planting" that may cut fertilizer input by 30%. And "we still need to incorporate disease resistance genes," says Reeves. But he thinks the new plant may be ready for deployment in 5 years. Just where it can grow awaits the result of multicountry trials yet to begin.
