First hollow stem update: March 6, 2018
Cattle should be removed from wheat pastures when the crop reaches first hollow stem (FHS). Grazing past this stage can severely affect wheat yields (for a full explanation, please refer to eUpdate article “Optimal time to remove cattle from wheat pastures: First hollow stem” in the Feb. 23, 2018 issue).
First hollow stem update
In order to screen for FHS during this important time in the growing season, the K-State Extension Wheat and Forages crew measures FHS on a weekly basis in 28 different commonly grown wheat varieties in Kansas. The varieties are in a September-sown replicated trial at the South Central Experiment Field near Hutchinson.
Ten stems are split open per variety per replication (Figure 1), for a total of 40 stems monitored per variety. The average length of hollow stem is reported for each varieties in Table 1. As of March 6, none of the varieties had yet reached FHS but all varieties had started to elongate the stem.
Figure 1. Ten main wheat stems were split open per replication per variety to estimate first hollow stem for this report, for a total of 40 stems split per variety. Photo by Romulo Lollato, K-State Research and Extension.
Table 1. Length of hollow stem measured Feb. 21, Feb. 28, and Mar. 6, 2018, from 28 wheat varieties sown mid-September 2017 at the South Central Experiment Field near Hutchinson. The critical FHS length is 1.5 cm (about a half-inch or the diameter of a dime).
None of the varieties had yet reached FHS as of March 6, and interestingly, there has not been much development since the last measurement taken on February 28. While FHS is usually achieved within a few days from when the stem starts to elongate, the below-average temperatures and extremely dry topsoil conditions experienced during the period between both measurements have slowed down crop development. Nonetheless, we advise producers to closely monitor their wheat pastures at this time.
The intention of this report is to provide producers an update on the progress of FHS development in different wheat varieties. Producers should use this information as a guide, but it is extremely important to monitor FHS from an ungrazed portion of each individual wheat pasture to make the decision of removing cattle from wheat pastures.
Romulo Lollato, Wheat and Forages Specialist
Larissa Bonassi, Visiting Assistant Scientist
Felipe Spolidorio, Visiting Assistant Scientist
Jose Guilherme Cesario Pereira Pinto, Visiting Assistant Scientist
Cody Brown, Graduate Research Assistant
Gustavo Bacco, Graduate Research Assistant
Edwin Navia, Visiting Assistant Scientist