First hollow stem occurs just prior to jointing and is the optimal time to remove cattle from wheat pasture. Grazing past first hollow stem can reduce wheat grain yield by as much as 5% per day and the added cattle gains are not enough to offset the value of the reduced wheat yield. Checking for first hollow stem is fairly easy.
- You must check first hollow stem in a nongrazed area of the same variety and planting date. Variety can affect date of first hollow stem by as much as three weeks and planting date can affect it even more.
- Dig or pull up a few plants and split the largest tiller longitudinally (lengthways) and measure the amount of hollow stem present below the developing grain head. You must dig plants because at this stage the developing grain head may still be below the soil surface.
- If there is 1.5 cm of hollow stem present (see picture below), it is time to remove cattle. 1.5 cm is about the same as the diameter of a dime.
- Detailed information on first hollow stem can be found at www.wheat.okstate.edu under ‘wheat management’ then ‘grazing’
We check for first hollow stem in our forage trials each year. These can be used as rules of thumb, but you will still need to check your own fields. Our Chickasha plots were sown September 20, 2012 and have had fair growing conditions. First hollow stem was measured on February 18, 2013 and the results are presented in the table below. Gallagher and Everest are just past first hollow stem and Razor is not far behind. I predict that most varieties will be past first hollow stem by March 1.
|Variety||Hollow stem* 02/18/13|
|*Average of ten hollow stem measurements in wheat sown 09/20/12 at Chickasha, OK|