First Hollow Stem Update

Apr 13, 2023

By Romulo Lollato

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 the eUpdate article “Optimal time to remove cattle from wheat pastures: First hollow stem”).

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 21 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 variety in Table 1. As of April 3, 2023, all varieties had already reached first hollow stem. Cattle should be removed from wheat pastures if these are to be harvested for grain yield.
en main wheat stems were split open per replication per variety

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 on February 22, 27, March 6, 13, 20, and 27, and April 3 for 21 wheat varieties sown mid-September 2022 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). Value(s) in bold indicate the highest FHS group.

	First hollow stem (cm)
Variety	2/20	2/27	3/6	3/13	3/20	3/27	4/3
AM Cartwright	0	0	0.08	0.19	0.26	0.86	2.56
AP EverRock	0	0	0.08	0.29	0.35	1.18	5.61
AP Prolific	0	0	0.04	0.16	0.2	0.61	2.95
AP18 AX	0	0	0.06	0.3	0.31	0.64	2.93
ARMOR EXP55	0	0	0.05	0.24	0.31	0.97	2.82
ARMOR EXP6 AX	0	0	0.05	0.29	0.36	1.05	3.68
CP7017 AX	0	0	0.06	0.29	0.31	0.91	3.32
CP7050 AX	0	0	0.06	0.27	0.42	1.13	4.91
CP7266 AX	0	0	0.07	0.2	0.27	0.7	2.88
CP7869	0	0	0.08	0.26	0.35	0.93	2.53
CP7909	0	0	0.11	0.23	0.31	1.33	4.43
Guardian	0	0	0.05	0.22	0.21	0.91	3.17
Kivari AX	0	0	0.08	0.21	0.35	0.91	3.11
KS Ahearn	0	0	0.09	0.21	0.28	0.46	2.69
KS Hatchett	0	0	0.06	0.18	0.38	2.03	-
KS Providence	0	0	0.07	0.2	0.31	0.65	2.94
LCS Atomic AX	0	0	0.06	0.32	0.58	2.68	-
LCS Galloway AX	0	0	0.06	0.22	0.33	1.21	3.99
LCS Steel AX	0	0	0.05	0.25	0.3	0.95	2.25
LCS19DH-152-6	0	0	0.02	0.17	0.32	0.78	2.75
Whistler	0	0	0.05	0.25	0.28	0.62	2.12

The intention of this report is to provide producers with an update on the progress of first hollow stem 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 take the decision of removing cattle from wheat pastures.

Source : ksu.edu