First hollow stem (FHS) is the optimal time to remove cattle from wheat pasture (a more detailed explanation can be found by clicking here). Each year, we collect FHS measurements from the varieties in our forage variety trials. This year, we have two forage variety trial locations, Chickasha and Stillwater. Both locations were sown in mid-September. To give you a point of reference, under normal conditions approximately 50% of the varieties reach or pass FHS by March 1st at Stillwater. However, with the warmer than normal temperatures and estimates from the First Hollow Stem Advisor on the Oklahoma Mesonet, we have begun collecting our FHS measurements.
Listed below are the first set of FHS measurements from our Chickasha location (Table 1). A couple of the ‘early’ varieties are beginning to show hollow stem, but none of the varieties have reached FHS at this time. However, with the recent rainfall and warm forecasted temperatures, I suspect some of the early varieties will reach FHS very soon. I also need to provide you a word of caution with the Chickasha results. Based on how we collected our forage measurements this year, the FHS results at this location are coming from a simulated grazing situation. Grazing can delay the onset of FHS, which is why we recommend checking for FHS from a non-grazed area of the field (e.g., just outside the hot wire) to give a short buffer time for finalizing plans to remove the cattle. Because of this, there may be some varieties on this list if planted in the Chickasha area that may be closer to FHS than what is presented in the table. As always, keep in mind that wheat varieties in areas south of Chickasha may be further along, while varieties in areas further north may be a little behind yet. We are also taking measurements today from our trial at Stillwater, and I will get those results posted as soon as we get them summarized.
Table 1. First hollow stem (FHS) results by variety collected on 2/16/17 at Chickasha. Plots were sown on 9/15/16. The threshold target for FHS is 1.5 cm (approximately the diameter of a dime). The amount of hollow stem for each variety represents the average of ten measurements.