Researchers target drought-tolerant winter wheatDate posted: February 5, 2002
A new, major western Canadian study aims to improve winter wheat drought tolerance as the crop marches into more areas of the Prairies, including the drought-prone semiarid regions.
The University of Saskatchewan Crop Development Centre (CDC) winter wheat breeding program is searching for the right combination of traits for broadly adapted winter wheat varieties that will yield well, even in drought conditions. The research is part of a cereal crops environmental stress project that is partially supported by farmers through the Wheat Check-off Fund, administered by Western Grains Research Foundation.
Higher water-use efficiency helps give winter wheat a yield advantage over spring-seeded crops, says Dr. Brian Fowler, University of Saskatchewan CDC winter wheat breeder. However, like its spring-sown cousins, winter wheat experiences large yield losses because of droughts in the semiarid regions of Western Canada.
As winter wheat moves out of its traditional growing area in southern Alberta, due in part to its ability to escape Fusarium Head Blight and wheat midge infestations, tolerance to moisture stress must be addressed by crop improvement programs that target semiarid climates, says Fowler. In order to capitalize on these strengths, it is important that we understand the significance of the regional adaptation of genotypes.
Every year and every area is different in the level of drought stress that can occur, he says. That is why new, widely adapted cultivars and flexible management systems are needed to overcome variable patterns of water availability.
Fowler and his research partners in the project are now focusing on the factors that affect grain yield, such as number of tillers and kernel arrangement, to establish breeding guidelines for the production of varieties with high-yield potential and kernel uniformity.
The high-yield potential of many of the new, semi-dwarf winter wheat cultivars released over the past decade, is partly due to their ability to generate a large number of tillers in the spring, which in turn generates a high number of kernels, Fowler explains. High tillering capacity is an adaptation to low-stress conditions, but this early potential can be lost due to extensive tiller die-off under drought conditions.
Tiller die-back reduces the number of seeds that high-yield genotypes can produce, and limits the plants ability to respond to subsequent growing season weather conditions. We think that for improved drought resistance, vigorous tillers with numerous large kernels is the way to go.
In essence, the project is zeroing in on the architectural arrangement of yield components and how their arrangement can allow winter wheat varieties to adjust yield potential to variable water availability during the growing season, he says. This means grain yield can be maximized and the level of dockage due to variable kernel size can be minimized.
Fowler is also involved with cold hardiness research that is one component of a large Genome Canada crop environmental stress project. Both the drought resistance and cold hardiness projects, as they relate to winter wheat, are supported by the Wheat Check-off Fund.
Winter wheat offers many advantages, such as increased yield potential, soil conservation benefits, lower herbicide inputs, reduced disturbance to waterfowl habitat and planting flexibility, says Fowler. Hopefully, this research will help more Prairie farmers benefit from those advantages.
The Wheat Check-off Fund, administered by Western Grains Foundation, contributes $3 million annually to western Canadian wheat breeding programs. Other funders of the drought resistance project include Ducks Unlimited Canada and SeCan.
WGRF information at www.westerngrains.com
© 2002 Meristem Land and Science