First hollow stem update: March 22, 2019

Agronomy eUpdate

MANHATTAN – 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 a previous 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 36 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 18, 2019, none of the varieties had yet reached first hollow stem but all varieties had started to show minor stem elongation.

eUpdate02222017-First Hollow 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 March 18 of 36 wheat varieties sown mid-September 2018 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).

Variety Hollow stem length (cm)
  (3/18/2019)
AM Eastwood 0.63
Bentley 0.25
Bob Dole 0.39
Byrd 0.39
Doublestop CL Plus 0.28
EXP 0.39
EXP 40-1 0.21
Gallagher 0.44
Iba 0.35
Joe 0.29
Langin 0.35
Larry 0.29
Lonerider 0.37
NE10478-1 0.36
OK12716 0.36
OK13209 0.53
Paradise 0.44
Ruby Lee 0.39
Smith’s Gold 0.37
Spirit Rider 0.51
Stardust 0.49
SY Achieve CL2 0.63
SY Benefit 0.54
SY Grit 0.54
SY Rugged 0.28
TAM 204 0.39
Tatanka 0.48
WB4269 0.30
WB4303 0.67
WB4515 0.34
WB4595 0.45
WB4699 0.39
WB4792 0.37
WB-Grainfield 0.46
Whistler 0.31
Zenda 0.49

While none of the varieties had yet reached FHS as of March 18, there were statistical differences among the varieties evaluated and these differences tend to increase over time. Thus, we will report first hollow stem during the next few weeks again until all varieties are past this stage. Additionally, first hollow stem is generally achieved within a few days from when the stem starts to elongate, so 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 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.

Contact author: Romulo Lollato, Wheat and Forages Specialist, lollato@ksu.edu

Co-authors: Kavan Mark, Undergraduate hourly student, Marden Moraes, Visiting Assistant Scientist, Lohan Oliveira, Visiting Assistant Scientist, Nilo Fernandes Junior, Visiting Assistant Scientist and Caio Rapolla, Visiting Assistant Scientist

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