The Grain Growing Classroom

Wheat Is a Resilient Plant–And Other Lessons From 2006

By David Boehm

Could the growing seasons in 2005 and 2006 be any different?  For most growers in the Northern Plains, the past two years were exact opposites. Marked by excess early season moisture, 2005 saw heavy foliar disease pressure and one of the worst scab years we have witnessed.  The past growing season brought hot and dry conditions where diseases were hard to find.  Grain yields were expected to be really hampered, but in the end, wheat came through for many with one of the best crops in recent memory. Like always, there is something to be learned from what happened.

For growers in south central and southwestern N.D. and central S.D., it was one of the driest years on record, with many crops hayed or abandoned. My father harvested a 12 bushel per acre spring wheat crop west of Mandan, N.D. that maybe should have been taken for forage earlier. 

But outside of these bone-dry areas, most of the small grain crops didn’t experience a drought, as much as they underwent heat stress and a lack of rain.  Soil moisture levels existed for much of the region that the crop utilized and turned into pretty good yields.  We learned that wheat is a pretty resilient plant that can tap into deep soil moisture if needed. 

In 2003-04, summer rains kept roots higher in the soil profile, causing more lodging and lower grain proteins.  Because the wheat plant was stressed for water early in 2006, the roots traveled downward, and if they found water, the yields were normal or even higher.

Stored soil moisture based on crop rotation, planting date, and tillage made all the difference.  I visited with many growers who had large yield differences in fields with different cropping histories. As an example, wheat following sugar beets and sunflowers was under more pressure than wheat after soybeans or peas. 

A grower I work with in Crookston, Minn., had two neighboring fields planted to the same variety on the same day. The field on sugar beet ground produced 55 bu/ac while the other field on soybean ground ran over 80 bu/ac.  Another grower in south central N.D. told me that he has to rethink about sunflowers in his rotation and “charge” the following year’s wheat yield loss back to his sunflower returns. 

I would bet that most growers learned exactly what their soil conditions were this past year. Even driving around the region, you can spot any lighter soils or less-productive areas in fields.  When reporting yields this year, most growers will have to qualify their reports with statements like, “it was planted in this rotation, on this soil type, or planted on this date.”

The other major factor in 2006 was the absence of wheat disease, one good result from dry years.  The overall level of early season tan spot, summer leaf rust, and scab was markedly low. I have heard of large reductions in fungicide use and wonder if it paid off for those who applied it.  This lack of disease pressure may have been one of the biggest reasons yields were as respectable as they were. I believe our results might have been much different if leaf rust had become a problem and added to the stress the plant was already facing.

So what was the outcome from drier conditions and less disease?  Pick a variety that was planted on time, with good soil moisture and no disease pressure, and it probably performed pretty well. I have talked with growers all fall trying to find varieties that either did well or did poorly, and there are no consistent themes.  I have found no varieties that were heads-and-shoulders above anything else, and no varieties that just didn’t keep up. Foliar disease and scab susceptible varieties did just fine. Varieties with weak straw strength stood up well. Even varieties that are earlier in maturity didn’t have a real advantage this year.  Talk to 10 growers and you will have 10 different top-yielding varieties. 

While I like to hear success with wheat at any production methods, there still are things we can learn from 2006 to keep in mind as we choose varieties and plan for next year. 

Wheat Management Lessons

Make sure you look at three-year data when comparing varietal performance.  From a breeding perspective, it was a very difficult year for understanding test plot results. More disease, lodging, and yield separation would have helped to discard experimental wheat lines. The dry conditions amplified soil variation and forced us to abandon multiple locations.  If you think a lack of rain caused variability in a 160 acre field, throw a bunch of 5’x10’ plots in the same field and try to make these look consistent.  In shopping for wheat varieties, study results from various locations and seasons. Look at the statistical separation of the results (LSD, CV) to see if the differences really mean something. What varieties did well against scab and disease in 2005, as well as the drier conditions in 2006?  Look for these varieties, they are best bets for consistent performance.

Stick to your varietal plan. If you pick multiple varieties based on disease tolerance, protein, straw strength, etc., for your production issues, stay with that plan.   This past growing season will figure into determining “average data” but is not the best year to base your varietal choices.

Manage your varieties according to their weakness. Disease and lodging will come back.  Remembering that no variety is perfect, managing that weakness is the best chance to make it work for you.  Fungicides may be extremely important in 2007.

This might be a good year to take field notes and maps. Find the areas in your fields that are more or less productive. That could help you with fertilization and other land and inputs management issues, maybe even your rotation.

Continue to spread your risk. Grow multiple varieties with different maturities.  Mother Nature controls when and if you get rain, heat stress, frost, and disease.  The past few years have taught us that timing is everything.

One of our seed associates, Paul Anderson of Coleharbor, N.D. had a great quote in Prairie Grains a few years ago related to variety selection that’s worth repeating: “How many varieties do I recommend farmers grow?  Three.  In baseball, a career average over .333 should get you in the Hall of Fame. At planting time you just don’t know what the growing season will bring. To hedge the risk, plant a top yielder, a good protein variety and if scab has been a problem, a scab-tolerant variety. If you can do a little bit better than average on two of the three varieties you plant, and really hit it out of the park with one variety, long term you will survive and prosper.”