Crops & Conservation

The 2008 winter wheat crop had a challenge from the get-go. Western North Dakota (ND) experienced very dry seeding conditions during September 2007 and it continued to be very dry in the spring. Very little moisture fell after June 2007 west of the Missouri River and Highway 83 in ND. In fact, very little significant moisture was received until mid-May 2008 in many western locations. Eastern ND and most of South Dakota (SD) received adequate precipitation to establish winter wheat.Despite the challenging conditions, both ND and SD set some new records related to winter wheat production. SD set a new statewide record yield average of 55 bushels per acre. ND set a new winter wheat production record of 22.6 million bushels, but the average yield per acre fell nine bushels due to the dry conditions in western ND and winter injury.

Survival

Winter survival was a tale of two climatic regions and prior crop residues. North Central and Eastern ND and Northwest Minnesota had sufficient snow cover to provide insulation for winter wheat seedlings. This area also had adequate fall moisture to obtain good emergence and plant development prior to winter. South Central and Southeast ND had adequate fall plant development but had an open winter. A majority of SD experienced similar conditions to that of South Central ND.

Western ND had poor to good winter wheat emergence and plant development in the fall. Poor emergence and development was due to limited soil moisture and lack of prior crop residue to conserve what moisture that did fall. But despite the open winter, if the prior crop left adequate standing and surface residue to reduce soil water evaporation and catch the little snow that fell, winter wheat stands were often very good with cold tolerant varieties. Conversely, if the soil surface had limited surface residue, stands were spotty and plant development hindered. Many fields saw germination occur following a two or three tenths inch rainfall in September and maybe one additional rain of a similar amount in early October.

Pea, soybean and harrowed canola stubble fields were the three prior crop scenarios that witnessed the greatest winter wheat stand reductions. Canola fields that maintained adequate standing stubble after winter wheat seeding experienced good winter wheat survival. The old “rule of thumb” seems to apply and that is if there is a combination of no soil moisture and little standing residue at seeding time, it may be better to wait with seeding or select a different field. If you have soil moisture or good standing stubble, survival often times is successful when the variety planted has good winter hardiness.

Fields that had minimal prior crop residue, such as prior crop pea and soybean fields, and were seeded with a shank drill, sometimes experienced greater survival due to the depressed furrow of the shank opener and some soil movement to hold the pea residue on the field.

Winter wheat varieties with greater cold tolerance sometimes made the difference between a field being destroyed or harvested in minimal cover fields. Differences between winter wheat varieties became more evident when either soil moisture stress was present or standing residue was not adequate. One example was at the Dickey County variety trial. There were four replications and the first rep had very little standing residue but fair surface residue from the prior spring wheat crop. The Kansas varieties suffered stand loss and injury in the first rep but had good stands and yield in the three remaining reps that had good standing residue.

When survival is an issue, many management decisions and environmental stresses can make a difference. Seeding depth and date issues, in combination with fields containing little surface or standing residue and less cold tolerant varieties made fields a potential candidate for reseeding in the west. Each stress becomes additive in this type of environment. A seeding depth of 1 to 1.5 inches is recommended for winter wheat seeded into moist soils. When seeding in dry soil, seed germination will not occur immediately, or if seeding in late September, place winter wheat seed at a 1” depth.

Winter wheat seed that was hair-pinned at seeding experienced more loss due to the open winter and the exposure of the winter wheat crown to fluctuating air temperatures. This results because the seed trench is not properly closed and the crown is exposed to the surface air temperature. The key is to do a good job of spreading the straw and chaff back across the width of the header and not to leave any residue bands.

The dry soils of Northwest ND revealed a new challenge at seeding time in the fall of 2007. Some soil types within fields were much firmer than others and caused some shank drills to vary their seeding depth by more than an inch. The variety Jerry survived in prior cropped pea fields in the soils where it was seeded 1.5” deep, but did not survive in the soils where it was seeded 2.5” or deeper. The crown development was significantly reduced by the delayed emergence from the deeper seeding depth.

Diseases

Weather in 2008 provided for low-to-moderate disease pressure with rust appearing very late in the growing season. Early disease pressure was low due to the cool and dry conditions. It was still important to protect the flag leaf from diseases such as tan spot and septoria, particularly in the eastern parts of the Dakotas and where yield potential exceeded 50-60 bushels/acre. Fusarium head blight or scab was present, but in low levels.

Yield increases from fungicide application were variable in the trials. SDSU conducted two intensive management winter wheat variety trials at Brookings and Winner. The intensive management treatments increased yields by 12 and 5 bushels per acre, respectively.

The winter wheat variety trials conducted by Dr. Joel Ransom and Dr. Marcia McMullen, NDSU, and Ducks Unlimited at Lisbon, ND experienced a 18.3 bushel/acre average yield increase for the 20 varieties. A split fungicide treatment of Headline with the herbicide and Prosaro at the early flower stage of growth was applied.

Kent McKay, Vision Research in conjunction with NDSU Minot, conducted a fungicide trial with 10 varieties at Berthold and Underwood, ND. Yield response was minimal in the dry areas depending on the variety.

Wheat streak mosaic virus was actually observed in many fields, but at a very low incidence level. We recommended the destruction of two fields in all of our visits. In one case, winter wheat volunteers from the 2007 winter wheat crop were not controlled in the fall and winter wheat was seeded back into the same field. The second case involved a field of winter wheat seeded into spring wheat stubble. The spring wheat volunteers had been controlled in the field to be seeded. The neighboring field had winter wheat volunteers that had not been controlled far enough in advance to cause complete volunteer winter wheat desiccation before the new winter wheat field emerged. Once the volunteer winter wheat desiccated the mites moved to the new winter wheat seedlings from the neighboring field.

To manage the disease wheat streak mosaic, control volunteer small grains and grassy weeds two weeks prior to seeding winter wheat to eliminate the “green bridge”. Wheat streak mosaic is spread by the wheat curl mite. Volunteer small grain and grassy weeds are the hosts for the mite. Eliminating the grassy hosts breaks the life cycle of the mite and stops the spread of the disease. Neighboring corn fields can also be a host for the mite. Mite populations in corn generally decline rapidly once the corn husk dries and opens.

Seeding later during the optimal seeding period can assist in reducing exposure to wheat streak mosaic. Many of us needed to seed a little later last fall as rain showers occurred two or three times per week in some areas, causing several flushes of volunteers. This made it challenging to break the green bridge. NDSU has a wheat streak management bulletin online at www.ag.ndsu.edu/pubs/plantsci/smgrains/pp646w.htm.

Controlling volunteer winter wheat in the past year’s winter wheat field(s) is a must. The best time to control the volunteer winter wheat after harvest is late in the fall or the very first field activity performed the following spring. One exception is, if you are planting winter wheat in close proximity to a prior year’s winter wheat field, be sure to control the winter wheat volunteers in the neighboring field prior to planting the new field of winter wheat.

Record Yield in SD and Production in ND

According to the 2008 National Agricultural Statistics Service data, South Dakota achieved records in winter wheat yield and total production. The state average winter wheat yield was 55 bushels/acre eclipsing the old record from 2007 by 7 bushels. They produced 103.95 million bushels. The spring wheat average yield was 45 bushels/acre.

North Dakota’s winter wheat area harvested for grain totaled 550,000 acres, equaling the prior record in 1984. ND produced a record 22.6 million bushels. The yield 41 bushels/acre, was down 9 bushels from last year. ND’s spring wheat average yield was 38.5 bushels/acre.

Minnesota winter wheat acreage also continues to increase with 70,000 harvested acres with a yield of 52 bushels/acre. Montana harvested 2.42 million acres of winter wheat in 2008 with a 39 bushel/acre yield.

South Dakota and eastern North Dakota experienced great winter wheat yields once again ranging from 40 to over 100 bushels/acre. The Dakota Farmer reported a farm average yield of 108 bushels/acre on 820 acres of winter wheat west of Chamberlain, SD. As you moved west in ND, the yields ranged from zero to 70 bushels/acre depending on rainfall and survival. I am still receiving feedback on yields and in most cases the winter wheat still out yielded its spring wheat cousins, but not always in the west.

Record Price

Many crops set record price levels in 2008 and winter wheat was included in that group. Mike Nickolas, North Central Farmers Elevator, Ipswich, SD and Dan DeRouchey, Berthold Farmers Elevator, Berthold, ND, provided the following prices. Current winter wheat cash prices range from $5.00 to $5.50/bushel. The high cash prices in March 2008 ranged form $14 to $18/bushel. The top harvest delivery price back in March for the 2008 crop was in the $12 plus range.

As we all know, the high wheat prices in August and September of 2007 were not as encouraging in the fall of 2008. However, I believe the same or more winter wheat was planted in ND for the 2009 crop, but probably less in SD. Winter wheat’s ability to maintain or increase its acres points to the fact that growers continue to experience the benefits of spreading the workload and risk and good profitability that winter wheat adds to the rotation.

Prospects for 2009 are very good with almost all areas obtaining good stand establishment this past fall with much better soil moisture recharge. In addition, we now have a nice blanket of snow for insulation. We are already two steps ahead of 2008 in some regions.

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, online at www.ducks.org/agronomy.

Observations from the 2008 winter wheat growing season were due in part to the following individuals: Dr. Joel Ransom, Dr. Marcia McMullen, Kent McKay, and Greg Endres of NDSU; Dr. Jochum Wiersma of the University of Minnesota; David Boehm of AgriPro Wheat; Roger Knapp, DU field agronomist; and Alan Ness, consulting agronomist.