Alan Ness and Greg Endres asked me to address several issues regarding winter wheat management. Alan suggested the topics of rotations, drill openers and varieties. I will also share results from a winter wheat trial comparing nitrogen application timing and fungicide application.

Rotations (slides 3 to 9)

Dr. Dwayne Beck at Dakota Lakes Research Farm at Pierre, SD probably has the best information for rotations including winter wheat in the Northern Plains of the U.S. The data consistently shows winter wheat to be the most profitable of the crops in the three rotations displayed on their web site over a nine-year period. Winter wheat also tends to be one of the lower cost of production crops. Be sure to study the profitability of the overall rotation. The rotations profitability is the real bottom line.

The three rotations with listed data are a WINTER WHEAT / CORN / COOL SEASON BROADLEAF rotation; HRSW / WINTER WHEAT / CORN / WARM SEASON BROADLEAF rotation; WINTER WHEAT / WARM SEASON BROADLEAF / CORN or SORGHUM / COOL SEASON BROADLEAF rotation.

The rotation including the cool season broadleaves of peas and lentils exhibited the greatest variability and highest yield at 94 bushels per acre and the lowest yield at 32 bushels per acre. It also produced the lowest average yield of the three rotations at 62 bushels per acre over the nine years. Planting winter wheat on peas and lentils may be the most desirous from a yield perspective, but these crops also have less ability to trap snow. There may be more winter injury resulting in lower plant populations and reduced yields in some years.

The winter wheat was most profitable in the WINTER WHEAT / CORN / COOL SEASON BROADLEAF rotation. Winter wheat will likely yield more following a broadleaf crop than another small grain. However, there is usually less snow trap potential following a broadleaf crop than a small grain crop and this should be considered as you select a winter wheat variety. Rotation also can impact disease and the number of fungicide treatments that may be necessary.

The winter wheat survival and yield slide (9) lists my experience with winter wheat following those crops.

Shank verses Disk Openers (slides 10 and 12)

Drills equipped with either shank or disk openers can be used for planting winter wheat. There are some management considerations for each type of opener. The prior crops stand ability is an important consideration for both drills.

A disk drill tends to perform better with less surface residue and more standing residue in order to avoid hair pinning. Hair pinning can cause poor germination and plant development and if the seed trench stays open, it can be a conduit for cold air to an exposed winter wheat crown. I encourage growers with disk drills to leave as much standing residue as possible and do a very good job of spreading the straw and chaff with the combine. Managing the front and the rear of the combine is important. Modern disk drills tend to have depth gauge wheels with each opener, which gives them an advantage in depth control. Seeding depth is an important management concern with winter wheat as exhibited by the winter wheat growth from the various seeding depths in slide 12.

A shank drill tends to work better in shorter to medium height stubbles. For example, a prior small grain crop combined with a stripper header is generally going to cause a lot of plugging problems for a shank drill. However, most shank drills should be able to negotiate 16-inch small grain stubble depending on the shank spacing and numbers of ranks. However, a 16-inch stubble height is more than adequate for snow trap. Surface residue is less of a concern with a shank drill, but straw and chaff spreading is still important. The trench left with a shank drill may add to the survival protection package. However, standing residue is more important than the trench.

It is important for several reasons to reduce your travel speed when seeding winter wheat with a shank drill. Slower speeds increase the amount of standing residue after seeding and allows for better trash flow. It also provides for more uniform depth of seeding, particularly in dry seedbed conditions. Shank drills should be equipped with a narrow opener rather than a shovel or sweep. Anderson, Dutch and other openers can do an adequate job of leaving standing residue when used at an appropriate travel speed and still allow you to spread the seed and apply banded fertilizer.

Varieties (slides 13 to 17)

Variety selection is not only based on yield, but on the seedbed conditions and the prior crops residue condition that you are seeding into and the winter hardiness of the variety. More winter hardy varieties should be selected when the height and density of the prior crops residue is minimal following seeding. Less winter hardy varieties can be selected when there are good prior crop residue conditions. This may open the window to less winter hardy varieties that may have better stand ability, yield potential and quality. Where you are located geographically in North Dakota or Manitoba also plays a significant role on the level of winter hardiness you select in a winter wheat variety.

Lodging plays a significant role in high-end yield management. A SDSU winter wheat variety trial from 1998 (good winter wheat year) is utilized to demonstrate the importance of lodging to maximizing yields (slides 14 to 16). The three varieties in our program with the best straw strength are Wesley (NE), CDC Falcon (Sask.) and Jagalene (AgriPro). Millennium (NE) is a close second. Jerry (ND), a taller variety, also has very good straw strength.

CDC Falcon and Jerry have the good winter hardiness followed by Wesley and Millennium. Jagalene was developed for the southern states and should probably only be raised in very tall stubble south of Interstate 94 in North Dakota. Harding (SD) has fair winter hardiness, between CDC Falcon and Wesley, and has pretty good protein. It does not have the straw strength of the other varieties, but can stand to 70-bushel yield levels. The highest to lowest protein levels are Wesley, Jagalene, Harding, Jerry, Millennium, and CDC Falcon.

As you move west in the Dakota’s, Wesley and CDC Falcon tend to lose their yield advantage in the drier environments. A newer variety from Nebraska, Wahoo, has been performing quite well further west. Straw strength appears to be similar to Jerry with winter hardiness similar to Wesley. CDC Falcon and Jerry should become the dominant varieties in the northern part of North Dakota.

In visiting with my DU counterparts in Canada, they indicated CDC Falcon, CDC Harrier and CDC Clair are currently most popular. To compete with the HRWW variety quality in the U.S., Canada has added the "Select" division to the hard red winter wheat class. McClintock and CDC Buteo, two new releases, meet the Select class requirements and may be varieties to watch in the near future.

Slide 17 is 2003 variety results averaged over nitrogen timing treatments and fungicide verses no fungicide treatments. The information regarding the plot management is contained in slides 23 and 24. An individual Wesley plot yielded 114 bushels per acre with early nitrogen and fungicide.

Disease and Nitrogen Management Trial (slides 18 to 33)

Slides 18 to 21 contain data from Lisbon, ND trials conducted by Dr. Marcia McMullen and Scott Meyer, NDSU, and reflect the yield increases that can be obtained with fungicide application to winter wheat in a good environment. You will note that in 2002 when the yield potential was limited to 45 bushel per acre, the fungicide applications were break even at best. Dr. McMullen’s trials seem to indicate that split applications are most consistent. You will generally receive a return on your investment when yield potential reaches 45 to 50 bushel per acre or higher.

Slides 22 to 30 are information on a nitrogen time of application study with a fungicide verses no fungicide application comparison. Ten varieties of winter wheat were planted nine miles east of Ellendale, ND on the Larry and Jane Anderson farm on September 13, 2002. All varieties were seeded at 100 lbs/A at a depth of 1.5 inches and 10-34-0 fertilizer was applied at 5 GPA. The plots were seeded in spring wheat stubble with a Horsch Anderson air plot drill with 15-inch shank spacing. Shanks were equipped with Anderson triple shoot openers. The seed spread was 5 to 6 inches and the fertilizer placed between and below the seed.

Forty-five pounds per acre of actual nitrogen was applied. The soil test indicated 138 pounds of nitrogen with 60 pounds in the 0-6 inch soil depth and 78 pounds in the 6-24 inch depth. Puma + Bronate Advanced + Tilt was applied at 8 + 12 + 1 ounces, respectively. The June 18 Tilt was applied at 3 ounces per acre with a non-ionic surfactant at early flower or Feekes stage 10.51. The UAN stream bar nitrogen was applied to the wheat at the 4-leaf stage. Urea was used for the early nitrogen application.

Winter wheat plant populations were less than expected. There was no snow cover in February and March because of below average snowfall. Temperatures were also below normal during this period. There were 10 to 14 plants per square foot or 450,000 to 620,000 plants per acre based on the spring survival counts. Seeds planted ranged from 1.3 to 1.7 million per acre based on varietal seed size. Plants entered dormancy with 3.5 to 4 leaves and 0 to 3 tillers.

Dr. McMullen completed leaf disease ratings (slides 25 and 26) on July 1, 2003 at the late milk to early dough stage. The disease means are across both nitrogen treatments. Tilt fungicide significantly reduced Septoria and leaf rust levels when averaged over varieties. Nekota and Expedition exhibited higher levels of leaf rust. CDC Falcon had more Septoria. Dr. McMullen estimated the UAN stream bar applied plots had approximately 50% less disease, but that they were less mature at the time of disease rating.

As varieties reached maturity, general observations indicated that Millennium, Harding and Jagalene appeared to maintain the best leaf health. Leaf rust was not detected on CDC Falcon or Millennium.

The winter wheat trial was planted in spring wheat residue and fungicide was important in attaining top yields in the 2003 environment as indicated by the 12.8 bushel average increase (76.8 vs. 89.6) to Tilt fungicide applications. Tilt fungicide application appeared to have its’ greatest impact on those varieties with high yield potential and better straw strength as indicated in slide 27. Those varieties include Wesley, Millennium, Jagalene, CDC Falcon, Expedition, Nekota and Wahoo. The Expedition and Nekota yields increased 23.2 and 19.5 bushels, respectively, with fungicide application verses no fungicide. They are the same varieties that had significantly higher levels of leaf rust as indicated in slide 25. Fungicide application also had a significant impact on protein and test weight as indicated in slide 29.

Urea applied early with fungicide had the highest yield (92.6 bu.) when averaged over varieties as indicated by slide 28. UAN (28-0-0) applied at the 4-leaf stage with fungicide averaged 86.5 bushels and was better than urea applied early without fungicide at 79.6 bushels. The 4-leaf UAN nitrogen without fungicide had the lowest yield at 74 bushels.

Urea applied early (86.1 bu.) yielded more than UAN applied at the 4-leaf stage (80.2 bu.) when averaged over varieties as indicated in slide 30. Wesley and Nekota yielded more with urea applied early than with UAN applied at the 4-leaf stage. Although tiller counts were not taken, visual observation indicated that the early nitrogen application was more effective in stimulation of tillering that resulted in increased head numbers. This was important because of the low plant populations as a result of winterkill.

Conclusions from the trial indicate that urea applied April 1 had significantly higher grain yield than UAN applied with stream bars May 2 at the 4-leaf stage based on the conditions present at the site in 2003. Fungicide application had a significant impact on winter wheat yields, test weight, and % protein when planted in spring wheat residue in this high yield environment. Expedition and Nekota displayed the greatest sensitivity to leaf rust and the greatest yield response to fungicide application suggesting that leaf rust also contributed significant yield loss in addition to Septoria. The good Lord blessed us with great weather, but management decisions including choosing the correct variety, fungicide application, and nitrogen timing can make a significant difference.

Slides 31 and 32 show the result of a nitrogen shortage on barley growth and health. The message being conveyed in the pictures is that a nitrogen shortage early can have a negative impact on plant health. The poorly developed plant in slide 32 also has leaf spot disease problems as a result of the lack of nitrogen and crop residues.

Slide 34 is a yield monitor reflecting a 134-bushel per acre yield in a field of Wesley winter wheat in east-central South Dakota. The field, according to a Syngenta rep, averaged 128 bushels per acre. Slide 36 compares the overall trials average yield results of spring wheat and winter wheat variety trials at Langdon, Carrington and Minot. Slides 37 to 40 contain some general information on winter wheat management.