Issue 32
November/
December 2000

Prairie Grains is the official publication of the Minnesota Association of Wheat Growers, North Dakota Grain Growers Association, South Dakota Wheat, Inc. and the Minnesota Barley Growers Assocation.

Copyright Prairie
Grains Magazine
November/
December 2000

The Best Strategy For Selecting Varieties

By Dr. Michael D. Peel, NDSU Small Grains Extension Agronomist, mpeel@ndsuext.nodak.edu

"It was the best of times, it was the worst of times." So said the famous opening line in the Charles Dickens book, "A Tale of Two Cities." It might also describe the 2000 ND small grain crop, which ranged from the best ever recorded to some of the worst. 

In the southwest part of the state, wheat yields will probably set new records and the quality was good.  Conversely, in the north central region, yields would have been respectable, but there was a problem with Fusarium head blight (FHB, or scab) and then rain when the crop should have been harvested. This demonstrates the wide range of environmental conditions encountered throughout North Dakota and the region. It may not be obvious, but this illustrates the need to use information correctly when selecting a new variety.

So what is the best strategy for selecting a new, or the best, variety?  A simple enough question, but one in which too little attention is given, in my opinion. There are a few basic principles that should be remembered.

First, pest resistance, marketing factors (test weight and protein) yield and other agronomic characteristics should not be dealt with in the same manner. Let's use pest resistance for example. We want a variety in many growing areas with good resistance to scab.  So let's say we find a variety trial table from one year near our farm that lists yield, test weight, protein and includes a scab rating.  A tendency might be to view this information as though it is sufficient to select the variety that best meets our needs. Not necessarily, however.

Keep in mind that this was a variety trial; someone noted that scab was present and rated the trial. A close examination may reveal that few varieties in the table rated poorly under FHB pressure. Since none of the varieties were rated as poor, they apparently must perform well under FHB, right? Well, the fact is that the disease level in this particular plot trial may have been insufficient to differentiate among varieties. Thus, it is important to look and compare elsewhere for a rating among varieties.  This information can be found in the ND variety description tables. 

Varieties should meet minimum requirements
You will note in the ND variety description tables elsewhere in this issue (Tables 1a for wheat and 6a for durum) that several newer varieties are not rated for some disease, because too little information was available to rate them.  This lack of information should be viewed as a precautionary statement.

This same type of scenario can be described for lodging and other traits that are influenced by various plant stresses. In each variety description table are relative ratings for each variety. Judiciously using this information to eliminate varieties that do not meet minimum requirements should be the first step in selecting a variety.

Ratings for specific varieties are changed periodically. This is most frequent for leaf rust resistance. Prevalent races of leaf rust are continually changing, and when a new race appears that is virulent on a variety previously listed as resistant, the rating is changed.

Moisture, temperature, solar radiation, pest pressure and soil conditions to name a few are never the same from year to year, even at the same location.  A variety that performs very well at a single location in one year may look appealing.  Before choosing such a variety, look at its performance at other locations.  If it performs well at other locations, it is likely a good choice, but if it is poor at other locations then its performance is suspect.  Variety trials summarized over multiple locations and years provide the most reliable way to differentiate among varieties.  The top performing variety from this type of summary is the most adapted. On average, it has performed better under a range of environmental conditions.  Single year, single-location data provides the least reliable comparisons among varieties.

In 1999 and 2000, there were many new varieties of wheat, durum and barley released that look very promising.  Again, review the performance data properly on these new varieties before growing them. Frequently I get a call from an individual looking for information about a particular variety that I have not heard of.  If you can't verify the relative performance of a variety with multiple locations and years worth of data, either experiment with it on limited acreage next year, or don't gamble on it at all.