Two Kansas State University graduate students are urging cattle producers to evaluate wheat fields for signs of first hollow stem, an indication that they should be moving grazing animals off those fields.

“First hollow stem is a growth stage that we look for in our wheat to know when we need to remove cattle from these dual-purpose wheat fields,” said Claire Bott, a master’s student in K-State’s Department of Agronomy.

Warmer, wetter days – conditions seen across much of the Sunflower State recently — allow for the developing head of wheat to rise above the soil surface.

To identify the first hollow stem, Bott suggests that producers scout their fields for plants that have not been grazed down. Once a plant has been identified, locate the main stem of the wheat plant and split it lengthwise down the middle.

“When you do this, you can identify where the developing wheat head is, where that growing point is and there’ll be a hollow space that develops underneath it, and that’s what we call the first hollow stem,” Bott said.

The first hollow point is an indicator that the developing wheat head is emerging above soil level, and risks being damaged or grazed if cattle are not removed from the field in a timely manner. Bott said that if the developing wheat head gets damaged, the stem no longer has the capability to produce grain, which can drastically affect wheat yields.

“Even a single day that cattle are left on the field, letting them graze beyond the recommended point, producers are losing grain yield, up to even 2% of grain yield being lost every day that cattle are being kept on the field,” Bott said.

When observing the field for signs of the first hollow stem, researchers suggest collecting more samples than just along the fence line.

“We recommend that producers collect multiple samples out of a grazed area and out of the fence,” said Pradella, a doctoral student in K-State’s Department of Agronomy. “Identify and collect the most developed tiller and measure the distance between the crown to the head, and producers can observe if that hollow is longer than 1.5 centimeters.”

Pradella said that an easy way for producers to determine if the first hollow has reached a stage where they can pull the cattle off the field is to compare it to the diameter of a dime. When pulling samples from the field, if it is close to that 1.5-centimeter mark, they suggest beginning to check your fields daily to make sure you do not risk overgrazing.

“It is better to be a little proactive and avoid losing grain yield, because even one additional day that you graze, the little bit of forage that you gain in that day is not going to economically outweigh the losses of grain yield,” Bott said.

Pradella added that there are tools available for producers to understand when to start scouting their fields.

“The Kansas Mesonet system has a predictive model that is used to estimate the percentage of the tillers that have achieved the first hollow stem per region,” Pradella said.

If producers plant multiple fields of the same wheat variety in proximity, it is still best practice to check the fields individually.

“Each field has variability. We strongly recommend that the farmer makes their decision per field,” Pradella said.

More information on wheat first hollow stem can be found from K-State’s Department of Agronomy.