UNL CropWatch March 31, 2011 Winter Wheat Off to a Slow Start, Still able to Rebound

UNL CropWatch March 31, 2011 Winter Wheat Off to a Slow Start, Still able to Rebound

 Wheat in tilled field at UNL's High Plains Ag Lab  No-till wheat at UNL's High Plains Ag Lab
Figure 1. Wheat sown into a tilled field at UNL's High Plains Ag Lab near Sidney with a hoe drill that moved dry soil into a ridge, allowing the seed to be placed into moist soil. Figure 2. Spotty wheat field at UNL's High Plains Ag Lab sown with a no-till disk drill shows wheat that emerged last fall and some that has recently emerged.

 March 31, 2011

Winter wheat is starting to show signs of new growth this spring, amid concerns in some areas about late-emerging and spotty stands.

In the southern Panhandle thin, spotty wheat stands resulting from a dry fall and winter are common. In the northern Panhandle, where there was better moisture, stands are fair to good. In southwest Nebraska conditions were poor to fair and in the southeast, conditions were mostly fair.

On Monday the Nebraska Field Office of USDA’s National Agricultural Statistics Service reported that wheat conditions statewide rated 3% very poor, 14% poor, 43% fair, 36% good, and 4% excellent, below last year.

Nebraska map of winter wheat condition

Figure 3. The condition of Nebraska’s wheat crop by district, as reported in the March 23 Nebraska Wheat Crop Report by Caroline Brauer, intern with Nebraska Wheat. The latest report can be found under the Buyers and Processors tab at www.Nebraskawheat.com.

Western Nebraska

Dry conditions during late summer and fall in much of western Nebraska resulted in dry, hard surface soil. Many growers delayed seeding in hopes of receiving moisture, but when timely rains didn’t occur, they planted into less than ideal conditions. Many disk drills had difficulty reaching moist soil given the hard ground and lower soil moisture line. This was particularly true in fine-textured soils under no-till management. Rains in mid to late October were too late to aid plant emergence, particularly at the higher elevations in the Panhandle.

Injured wheat roots

 Figure 4. Wheat stand condition and winter survival are improved in no-till fields where residue captures blowing snow and moisture.

wheat injury

Figure 5. Wheat plants with winter injury due to dry soil and lack of growth in the fall.

Wheat root comparison

Figure 6. Roots on the left are barely developed due to poor seed penetration into hard, dry soil last fall; the seed for the plant on the right was placed into deeper, moister soil that allowed for better root development and a stronger start for the plant.

Planting was also delayed in some areas due to concerns about grasshoppers potentially feeding on seedlings.

Spotty winter wheat stands last fall in the southern Panhandle and parts of southwest Nebraska created a worrisome situation for soil erosion (See Jan. 28 CropWatch article), but for the most part, wind erosion was not serious this winter.

As spring arrives in fits and starts, we should get a better feel for how the winter wheat crop survived. Seedlings that emerged late last fall, but were unable to produce more than one leaf, were at greater risk for winter injury than plants that produced two or more leaves last fall. Emerged wheat in no-till fields with crop residue caught more snow and seemed to survive the winter better than wheat in clean-tilled fields.

At this time, we don’t know what percent of the seedlings that emerged last fall germinated and died due to dry soil conditions or never germinated or germinated but didn’t emerge. All of this should become clearer over the next few weeks.

Wheat growers remain hopeful that barren areas will fill in this spring. Some of this is already occurring (Figure 1). Winter wheat that does not emerge until this spring will produce few tillers and will probably finish later and yield less than wheat that emerged last fall. Wheat that germinated and was exposed to several weeks of cool temperatures after germination will be vernalized and produce a seed head in a timely manner. With current wheat grain prices, growers should be slow to decide to tear out their wheat due to poor stands. However, growers with a lot of late-emerging wheat should carefully consider their weed control options.

Weed Control in Late Emerging Wheat

Late emerging wheat will not be as competitive with weeds as wheat that emerged last September. To prevent possible harvest problems and to reduce yield loss due to weed competition, consider using herbicides in these fields. If crop rotations allow, consider herbicides with extended soil residual activity, for example Ally®, Amber®, Finnesse®, or Rave®. Dicamba, and to a lesser extent 2,4-D, can provide a few days to a week or two of residual control of broadleaf weeds. However, wheat that has fewer than four tillers is more susceptible to injury from synthetic auxin herbicides like dicamba and 2,4-D.

Spring Wheat Fill-in Not Recommended

Substituting spring wheat for winter wheat in thin or spotty stands is not recommended in most locations. Spring wheat and winter wheat are different classes of wheat and mixed grain delivered to the elevator can be severely docked. Spring wheat generally matures later and is significantly lower yielding than winter wheat. If winter wheat stands are so poor that the wheat must be abandoned, other crops which will be much more profitable than spring wheat. In the northern Panhandle, spring wheat occasionally will yield well, but in all other parts of the state, corn or another crop commonly grown in the area should be considered.

With a little rain, winter wheat in western Nebraska should be able to overcome this slow start. Remember, like cats, wheat has at least nine lives.

Drew Lyon, Extension Dryland Cross Specialist, Panhandle REC, Scottsbluff
Bill Booker, Extension Educator, Box Butte County
Bob Klein, Extension Western Nebraska Crops Specialist, West Central REC, North Platte
Greg Kruger, Extension Cropping Systems Specialist, West Central REC, North Platte
Greg Dorn, Research Technologist
P. Stephen Baenziger, UNL Eugene W. Price Professor, Lincoln

Eastern Nebraska

Wheat in eastern Nebraska had the benefit of more subsoil moisture and more fall rains. Spotty stands can be found in some eastern Nebraska wheat fields, particularly in wheat that was seeded into dry soil conditions.  About 75% of the wheat planted last fall in Gage County is coming out of dormancy and looks good. The other 25% never emerged, which isn't particularly unusual.  Wheat in this area has a 70% chance of making a normal crop.

In cases of spotty stands or where wheat didn't emerge, spring wheat is not recommended. Yield potential of spring wheat in south central Nebraska only about 35 bu/ac, given it gets hot too quickly for a good yield.  Oats also aren't a good option for interseeding unless you want a forage crop. If so, plan to reseed to a summer forage after harvest.

In southeast and south central Nebraska, fertilizers and herbicides were being applied this week.  We've had a few questions regarding adding a reduced rate of fungicide to the fertilizer. While there have been some reports from Kansas of leaf rust overwintering, we haven't seen indications of that in Nebraska and many fields just didn't have that much growth going into winter for that to occur. If farmers are considering a fungicide now, we recommend leaving some check strips or contact your local Extension Educator and test via on-farm research to determine if the early fungicide made a difference.

In areas of eastern Nebraska where stands are substandard growers will be deciding soon whether to retain their wheat crop or terminate it and plant corn or soybeans.

Paul Hay, Extension Educator, Gage County
Jennifer Rees, Extension Educator, Clay County


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