Complete Wheat Tiller Counts Now to Determine the Need for Spring Nitrogen

Jarrod O. Miller, Extension Agronomist, and Amy Shober, Extension Nutrient Management and Environmental Quality Specialist;

Wheat is beginning to green up and is showing minimal freeze damage when compared to last year. There is still some time for wheat to develop more tillers before the first node emerges above ground. Now is a good time to go out and check for adequate tillering to determine the need for early spring N applications. Timing nitrogen (N) applications this spring will be difficult due to the amount of rainfall we have received.

To complete a tiller count, lay a yard stick (3 feet long) on the ground and count the tillers along the length of the stick. Multiply the number of tillers by 4 and divide that number by your row width. This will give you tiller density in tillers/sq. ft. Repeat these counts in five locations in the field and average the values. If you see large variability across your wheat, it may be a possible to identify regions in the field that are in greater need of N application.

Researchers at Virginia Tech determined that spring N application can be delayed until the first node is above the surface for wheat fields with more than 100 tillers/sq. ft. So if your fields show adequate tillering, we recommend holding off on spring N applications as the crop will not likely benefit from an application now and the potential for leaching is currently very high.

However, if the field has less than 50 tillers/sq. ft., at least half of the total spring N should be applied now so that the wheat crop can develop more tillers that will serve as future grain heads. Unfortunately, wet weather has probably kept most equipment out of the field, as it should. The compaction that would be caused by driving equipment on wet soils could cause issues throughout this and future growing seasons. However, it may be possible to fly on urea now, but try to wait for a drier period before you apply and keep N rates less than 30 lb/ac (20 to 30 lb/ac) to reduce leaching potential. The rest of the spring N can be applied later, when rapid growth begins. Plus, you get the potential yield benefits of the split application. Dr. Richard Taylor and Bob Unitaowski at the University of Delaware observed a 5 to 10% yield increase for winter wheat in research plots that received split spring N.