Wheat Research That Needs To Be Done

Published on: 11:10AM Oct 09, 2008
Vance Ehmke

One of the things that I look forward to each year is the K-State wheat variety trial information. To me, getting that information is literally like Christmas in July. I love to see how the varieties stack up against each other. Another thing that I enjoy is seeing how the varieties rate against diseases like wheat streak mosaic or how well they stand up to shattering, for instance.

But after reading those data for a number of years, I’d like to suggest that our researchers expand the number of things they rate the varieties for.

The first thing I’d like to see them start rating is the ability of the various varieties to suppress post harvest weed growth.

A number of years ago I was talking with Gail Wicks from the University of Nebraska’s North Platte Experiment Station. He told me a very interesting little story about this ability.

A farmer in the area was planting wheat and had done maybe l00 acres out of the l60-acre field. But he ran out of seed. And he had to switch varieties. So he went back to the house and got another variety to finish the field. Then later next year after harvest, he was out spraying the field to kill post harvest weeds like kochia and Russian thistle.

But when he reached the spot where he had switched varieties, all of a sudden there were no more weeds. The stubble was clean. So he stopped the sprayer and sat there trying to figure out what had happened. Then he finally realized—wheat varieties have an influence on post harvest weed growth. And in this case, it meant he didn’t even need to spray the rest of the field. What’s that worth today? $l0 or $l5 per acre? Two or three bushels per acre?

Here on our farm, since we grow rye and triticale, we see the same thing every year. Our rye and triticale stubble fields have no weeds in them while most wheat fields are green with weeds. Of course, our organic farmer friends have known about this for years and like to plant rye as a cover crop because it helps suppress weeds after the rye has been removed or plowed under. This is important to these guys because they can’t use herbicides.

But why aren’t there weeds in the stubble? It’s because of one of two things, or a combination of the two. Either certain wheat varieties or the rye and triticale are such competitive plants that they physically shade out or simply out-compete the weeds. Or the other possibility is that it’s because of a chemical or allelopathy effect—the plant puts something toxic in the soil which inhibits the growth of later weeds.

Gail said the University of Nebraska used to rate wheat varieties on this characteristic, but haven’t done so in a number of years. Well, maybe it’s time to take another look at this trait.

Another thing I’d like to see the universities rate is how strong the different varieties are in emerging.

Some years ago, K-State Extension wheat specialist Jim Shroyer told me about a French study he read about where the researchers measured the strength or torque of the coleoptile as it pushed its way through the soil to the surface.

We all know that the coleoptile length is influenced by soil temperature—warmer soils mean shorter coleoptiles. But my guess is that while variety has an influence, too, on length of coleoptile, it also has an influence on how hard it can push. And knowing more about length of and strength of the coleoptile could certainly be useful when selecting varieties.

And finally, your words of wisdom for the day come from noted farmer Bob Paris of Dighton KS: It only costs 90% more to go first class.