First hollow stem (FHS) is the optimal time to remove cattle from wheat pasture. This occurs when there is 1.5 cm (5/8” or the diameter of dime) of stem below the developing grain head (full explanation). Dr. Tracy Beedy, area Extension agronomist for the panhandle region, and her crew recently started collecting FHS measurements for 30 wheat varieties planted at the Oklahoma Panhandle Research & Extension Center. Results, including measurements taken yesterday (3/13), are listed below in Table 1. Keep in mind that several factors influence the onset of FHS. These include the wheat variety, location, temperature, available moisture, grazing, and planting date (later sown wheat will typically reach FHS later). The First Hollow Stem Advisor and the updates we provide give an indication of the FHS stem conditions in a particular area. However, because of the number of factors that can influence when FHS occurs, we cannot stress enough the importance of checking for FHS on a field-by-field basis. 

Table 1. First hollow stem (FHS) results by wheat variety collected from non-grazed plots at Goodwell on 3/9/17, 3/11/17, and 3/13/17. Plots were sown on 10/6/16. The threshold target for FHS is 1.5 cm (5/8” or the diameter of a dime). The amount of hollow stem for each variety represents the average of ten measurements. Varieties that have reached FHS are highlighted in red.