Water efficiency in wheat and the tortoise the hare

Farm and Ranch November 26, 2009 Part of the drought resistance research on wheat being conducted by the USDA’s Agricultural Research Service at Washington State University focuses on the water efficiency of the plant. ARS scientist Camille Steber is working to develop wheat plants that fix more carbon dioxide for the amount of water they put into the atmosphere.

Steber: “That ratio is important in that it gives you more yield for the amount of water that is taken out of the soil.”

Steber says this process is controlled to some degree by a plant hormone produced in the roots in response to drying soils.

Steber: “And it acts as a signal to the shoots, the leaves, to begin to close down the stomates in response to drought. The stomates are the pores where water escapes from the plant.”

So by making a plant that is more sensitive, it responds to the drought earlier and has a more conservative approach to using water. Steber says its like the fable of the tortoise and the hare.

Steber: “If you have a hare it is going to run through the water really quickly and then at the end it is going to run out of gas before it makes it through grain fill. If you have something that is a little bit more of a tortoise it will go more slowly on the water use early in the season but then you will have that water there to help with grain filling yield.”

Steber says part of the research involves looking for the genes related to this root hormone in existing varieties. After all she says breeders have been selecting for plants that do well and inadvertently may have been selecting for these genes.

I’m Bob Hoff and that’s the Northwest Farm and Ranch Report on the Northwest Ag Information Network.

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