Agricultural producers who plant winter wheat as part of a dual-purpose graze-and-grain management system need to ensure cattle are not grazing past first hollow stem stage of the crop, according to Oklahoma State University Division of Agricultural Sciences and Natural Resources recommendations.
Dual-purpose graze-andgrain operations account for about half of the wheat acreage in Oklahoma and a significant portion of wheat grown in northern Texas and southern Kansas.
Although grazing prior to first hollow stem, often referred to as FHS, typically has a limited effect on wheat yields later in the growing season, extended grazing beyond that stage can greatly reduce yields, said Amanda de Oliveira Silva, OSU Extension small grains specialist.
“Yield loss from grazing past first hollow stem can be as much as 1% to 5% per day,” she said. “It comes down to the amount of green leaf tissue left and the weather conditions after grazing. Cool, moist conditions after cattle removal allow for more time for the plants to recover.”
FHS occurs when wheat stems begin to elongate and the stem above the roots and below the developing head becomes hollow. Typically, this occurs when the hollow stem portion of the plant is 5/8 inch long. The occurrence of first hollow stem depends on the wheat variety and on climatic factors such as temperature and precipitation.
To check for FHS, go to a non-grazed area of the pasture and pull four to five plants. Plants must be dug up because much of the hollow stem present will be below the soil surface. Hollow stem must be measured from a nongrazed area in the same wheat field because the act of grazing delays stem elongation and therefore when first hollow stem occurs.