Crops & Conservation

Winter Wheat Breeding Program Resolution and Spring Nitrogen

by Blake Vander Vorst
bvandervorst@ducks.org

The Minnesota Association of Wheat Growers (MAWG) has passed a resolution to look into the possibility of establishing a winter wheat breeding program. Several discussions regarding the need for a winter wheat breeding program that looks more closely at the winter wheat varietal needs of Minnesota (MN) and North Dakota (ND) have occurred with MAWG board members, North Dakota wheat leaders and winter wheat growers throughout the region. 

Background
Actually, we need to take a step back and indicate that it was the late Tracy Sayler, Prairie Grains Editor, who was after MAWG and Ducks Unlimited (DU) on several occasions regarding this need. Tracy had scheduled a meeting with MAWG and DU staff to get the ball rolling regarding the establishment of a winter wheat breeding program on the unfortunate day of his passing. My suspicion is that Tracy may have also had discussions with the North Dakota Grain Growers (NDGGA) and Wheat Commission (NDWC) representatives.  Tracy recognized the potential of winter wheat for a number of reasons including its profitability. So, maybe the credit for another effort to promote wheat in the Dakotas and Minnesota belongs to Tracy.

Is there a need for a winter wheat breeding program in North Dakota or Minnesota? Before I answer, let’s start back in 1997 and 1998 when I had the fortune of doing some program analysis and development contract work for DU regarding waterfowl nesting in cropland.  The ag statistics data (see figure 1) indicated ND planted 60,000 acres and Minnesota 40,000 acres for the 1999 growing season, which was the first year of the DU winter cereals program. The graph shows the rapid growth in winter wheat acreage in ND to a projected 650,000 acres for 2008.

Figure 1. Minnesota and North Dakota Winter Wheat Planted Acreage, 1999 to 2008.

My initial recommendations to DU in 1999 was that a winter wheat breeding program was not an immediate need and would be a very challenging sell in light of the planted acreage of winter wheat.  In all reality, I thought the South Dakota (SD), Nebraska (NE), Saskatchewan (SK), and Manitoba breeding programs could meet our needs.  It is amazing how nine years can change your views.

Winter wheat variety development is currently occurring in the three Prairie Provinces in Canada and Montana, SD and NE, and by the private breeding programs of AgriPro and WestBred.  The three programs that supply a majority of the newer varieties being used in MN and ND are from the SK, SD and NE programs.  Many of the WestBred varieties were derived from the SK program.  AgriPro has a presence, but winter hardiness is a weakness of their varieties. Jerry, the last NDSU release before the program was eliminated a number of years ago, continues to hold a significant share of the planted acreage because of its good winter hardiness, however, its disease resistance is slowly decreasing with time and many growers would like a shorter variety.

Breeding needs
Because of climatic differences, a higher level of winter hardiness is a greater need for MN and ND as compared to the traditional winter wheat areas in SD and other states. Planting no-till in prior crop standing residues has dramatically assisted with winter survival.  However, not all prior crops provide adequate standing residue to catch snow for insulation.  For example, pea and soybean would likely provide the crop sequence for the highest winter wheat yields if winter injury could be minimized.

Winter wheat crown development is affected by seeding date and depth and moisture available for germination at planting.  Survival rates will be lower for plants with poorly developed crowns in comparison to plants with well developed crowns (see figure 2). Delayed emergence due to dry soils or late planting is common place in the Dakotas and MN. Varieties with better winter hardiness would be very beneficial in delayed emergence conditions to help compensate for fields where winter wheat crown development has been restricted.

Figure 2. Effect of Seeding Depth on Winter Wheat Plant Development and winter Survival.

Scab, leaf, stem and stripe rust, leaf spot, bacterial blight and wheat streak mosaic resistance are varietal characteristics where breeding improvements are necessary. Scab or Fusarium head blight resistance is of greater importance to the MN-ND area as compared to the states to the south and west.  Dr. Marcia McMullen, NDSU Extension Pathologist, has stressed on many occasions that winter wheat varieties have much less leaf and head disease resistance than their spring wheat cousins.

Reduced plant height and good straw strength are varietal characteristics desired by growers and is particularly necessary to achieve high yield goals.  Winter wheat yield is limited once lodging occurs.

Global warming
Quoting ND Farm and Ranch Guide article on Dr. Leon Osborne from the Regional Weather Information Center at UND “UND meteorologist predicts North Dakota will be the new Nebraska.”

“Global warming is causing the split in the jet stream but we don’t know what’s causing global warming.”  He says he continues to believe warming is partly human, partly Mother Nature.

“Climate variability is real and pervasive,” Osborne said. “You can’t just flip a switch and reverse it.”  He said he predicts with the trends continuing the way they are now that in 25 to 30 years, North Dakota will be the new Nebraska.  That would mean longer growing seasons, hotter summers, and “enough precipitation” in summer and fall.

If Dr. Osborne is correct, one only needs to reflect on the type of wheat that is grown in NE and realize that it is almost 100% winter wheat.  This is a result of the impact that high temperatures have on wheat and the yield advantage that winter wheat experiences because of its earlier maturity.

Another article in the January 2008 issue of Farm Industry News states: “Gradual Warming” “According to Gene Takle, an Iowa State University climatologist with the Regional Climate Modeling Laboratory, over the past 50 years, the number of frost-free days in central Iowa has increased by eight or nine days.  In Nebraska, and other parts of the Plains, the heading/flowering date of winter wheat, which is dependent on cumulative heat units during the growing season, has moved up a full two weeks over the past 70 years, adds Steve Hu, a climatologist at the University of Nebraska-Lincoln.”

Where do we stand now?
I do believe there is a need for a renewed effort in winter wheat breeding in MN and ND in light of the fact the Saskatchewan winter wheat breeding program may not exist after the retirement of its current breeder. Add to that the higher priority need in this region for scab resistance and winter hardiness, and I will have made a 360 degree change in my position on the need for a winter wheat breeding program from what I thought nine years ago.

I am not alone in my position as attested to by some of the survey responses from the Best of the Best meetings sponsored by the NDWC and the NDGGA in January and February as well as the MAWG resolution.  I have also had numerous winter wheat growers express the need for better varieties and a breeding program.

The trend in ND winter wheat and spring wheat yields are shown in Figure 3.  The yield trend reversal basically started in 2000 shortly after the DU program was initiated. The current increase in winter wheat yield is more due to production management changes in proper seeding, fertility and disease management from research, demonstration and education than new varieties. Future yield gains will also need to come from better genetics.

Figure 3. North Dakota winter Wheat and Spring Wheat Yield Trends.

I am looking forward to your feedback and future discussions on the need for a winter wheat breeding program.

Spring nitrogen management on winter wheat
Please remember the higher yield potential of winter wheat compared to its spring wheat cousin as you determine the nitrogen rate for your winter wheat crop.  The NASS yield trend line currently has a nine to 10 bushel yield advantage for winter wheat in terms of a ND average yield difference.  In ND, that yield difference grows as you move from northeast ND to the south and west.

It is also important to assess the level of winter injury and stand loss when the winter wheat is breaking dormancy. If stand loss and injury are significant, apply a 10 to 20 pound rate of actual nitrogen as early as possible to the surviving winter wheat seedlings to enhance root and top growth to increase tillering to compensate for stand loss.

Vander Vorst is regional agronomist with Ducks Unlimited, Inc., Bismarck, N.D. Find more information about DU’s agronomy program , including winter wheat performance data and production information, online at www.ducks.org/agronomy