WB-Cedar and Sy Llano reached first hollow stem this week, and there are several additional early-maturing varieties that are near first hollow stem. The results from a March 13 sampling of plots are posted below, and we will post results from another sample early next week. I have also posted the map from the Oklahoma Mesonet’s First Hollow Stem Advisor for medium maturity varieties. As indicated in the map, most wheat south of I-40 is likely at or past first hollow stem.

Probability of first hollow stem for medium maturity wheat varieties on 03/14/14

First hollow stem works as a pull off date for cattle on wheat pasture because it allows the plant a small amount of time prior to jointing to recover some of the green leaf area lost to grazing. As evidenced by the results posted on this blog, first hollow stem is running a good 1.5 to 2 weeks later than normal. Given the situation, it is advisable to consider removing cattle from wheat pasture sooner rather than later. In many cases this would be before the occurrence of first hollow stem. I make this recommendation because once our temperatures start to warm, it is likely that that wheat phenological development will proceed in rapid fashion. We could easily encounter a situation where there are only a few days separating first hollow stem and jointing. Pulling cattle from wheat pasture a little early will allow extra time for recovery, which might be needed this year.