Fall forage production and first hollow stem date in small grain varieties during the 2018-2019 crop year

Introduction

 Fall forage production potential is one of the major considerations in deciding which variety to plant. Dual-purpose wheat producers, for example, may find varietal characteristics such as grain yield after grazing and disease resistance to be a more important selection criteria than an advantage in early forage production potential. Forage-only producers might place more importance on planting an awnless wheat variety or one that germinates readily in hot soil conditions. Ultimately though, fall forage production is a selection criterion that should be considered. For more information on variety characteristics, please refer to OSU Fact Sheet PSS-2142 Wheat Variety Comparison Chart.

 

Fall forage production potential is determined by genetics, management and environmental factors. The purpose of this publication is to quantify some of the genetic differences in forage production potential and grazing duration among the most popular small grain varieties grown in Oklahoma. Management factors such as planting date, seeding rate and soil fertility are very influential and are sometimes more important than variety selection in determining forage production. Environmental factors such as rainfall amount and distribution and temperature also play a heavy role in dictating how much fall forage is produced. All of these factors along with yield potential after grazing and the individual producer’s preferences will determine which variety is best suited for a particular field.

 

Site descriptions and methods

The objective of fall forage variety trials is to give producers an indication of the fall forage production ability of small grain varieties commonly grown throughout the state of Oklahoma. The forage trials were conducted under the umbrella of the Oklahoma State University Small Grains Variety Performance Tests. During the 2018-2019 crop year, the forage trials were conducted at the Chickasha and Stillwater test sites. Additionally, first hollow stem measurements were collected at both sites. Weather data for each location are provided in Figures 1 and 2.

 

 

Figure 1. Average daily temperature (line graph) and rainfall (bar chart) from Sept. 1, 2018 to March 31, 2019 at Stillwater. Weather data courtesy Oklahoma Mesonet.

Figure 2. Average daily temperature (line graph) and rainfall (bar chart) from Sept. 1, 2018 to March 31, 2019 at Chickasha. Weather data courtesy Oklahoma Mesonet.

 

A randomized complete block design with four replications was used at each site. Plots at each location were established in a conventionally-tilled seedbed and received 50 pounds per acre of 18-46-0 in furrow at planting. The seeding rate for each small grain at both locations was 120 pounds per acre for wheat, triticale and rye; 96 pounds per acre for barley; and 65 pounds per acre for oat. Forage was measured by hand clipping two, 1-meter by 1-row samples approximately ½ inch above the soil surface from the interior rows within each plot. There was only one forage sampling date at each location. All samples were placed in a forced-air dryer after collection for approximately seven days and weighed. Fertility, planting date and clipping date information is provided in Table 1.

 

Table1  Location, planting, clipping, and soil information

 

 

First hollow stem sampling began mid-February at the Stillwater and Chickasha locations and continued every three to four days on a by-variety basis until varieties reached first hollow stem. Plant samples were collected for each variety by digging an approximately 8-inch section of row and selecting ten plants randomly from this sample. The largest tiller on each plant was split longitudinally, and the hollow stem below the developing grain head was measured. Varieties were considered to be at first hollow stem when the average measurement of the ten plant samples was 1.5 centimeter or greater. For more information on first hollow stem, refer to OSU Fact Sheet PSS-2147 First Hollow Stem: A Critical Wheat Growth Stage for Dual-Purpose Producers.

 

Results

As indicated in Figures 1 and 2, the 2018-2019 fall forage production season included moderate temperatures and plentiful rainfall that were conducive to fall forage production by small grains, and our results reflect these favorable conditions. Average wheat fall forage production at Stillwater was 2,260 pounds per acre and yields ranged from 1,710 to 3,050 pounds per acre. Average wheat forage yield at Chickasha was 3,450 pounds per acre and yields ranged from 2,850 to 4,150 pounds per acre. Average total fall forage production for the triticale, rye, barley and oat varieties at Chickasha was 3,170; 3,140; 3,250 and 2,320 pounds per acre, respectively (Table 4).

 

CR-2141 Table 2  Fall forage yields for winter wheat varieties at Stillwater during the 2018-2019 production year.

Notes: Shaded values are not statistically different from the highestyielding variety within a column. NS = not significant.

 

CR-2141 Table 3   Fall forage yields for winter wheat varieties at Chickasha during the 2018-2019 production year.  

Notes: Shaded values are not statistically different from the highest-yielding variety within a column. NS = not significant.

 

CR-2141 Table 4  Fall forage yields by triticale, rye, barley and oat varieties at Stillwater and Chickasha during the 2018-2019 production year.

Notes: Shaded values are not statistically different from the highest-yielding variety within a column for each crop. NS = not significant.
† P-value = 0.0542

 

CR-2141 Table 5   Occurrence of first hollow stem (day of year - March 1 = day 60) for winter wheat varieties sown in 2018 and measured in 2019 at Stillwater and Chickasha.

 

 

CR-2141 Table 6  Occurrence of first hollow stem (day of year - March 1 = day 60) for triticale, rye, barley and oat varieties sown in 2018 and measured in 2019 at Chickasha.

 † Deer feeding resulted in a delay in the onset of FHS. 

 

First hollow stem data are reported in ‘day of year’ (day) format for the winter wheat varieties in Table 5 and the triticale, rye, barley and oat varieties in Table 6. To provide reference, keep in mind that March 1 is day 60. February and March of 2019 were characterized by cooler-than-normal temperatures and resulted in slower plant development and onset of first hollow stem than normally expected for our region. The average winter wheat first hollow stem date at Stillwater was day 74 (March 15). This was four days later than in 2018 and eight days later than the previous 20-year average at this location. At Stillwater, there was a 28-day difference between the earliest and latest varieties, compared to a 20-day difference in 2018 and a nine-day difference in 2017. The average winter wheat first hollow stem date for the Chickasha location was 61 (March 2), which was three days earlier than in 2018 and the same date observed in 2017. At this location, there was a 27-day difference between the earliest and latest varieties, compared to a 25-day difference in 2018 and a 12-day difference in 2017.

 

Acknowledgments

The authors want to thank the Oklahoma Wheat Commission and the Oklahoma Wheat Research Foundation for providing partial funding for this research.

 

Seed Sources and Abbreviations

AGSECO = AGSECO Inc.

AgriMAXX = AgriMAXX Wheat

AgriPro = AgriPro|Syngenta Seeds

CROPLAN = CROPLAN by WinField United

Dyna-Gro = Dyna-Gro Seed

KWA = Kansas Wheat Alliance

LCS = Limagrain Cereal Seeds

OGI = Oklahoma Genetics Inc.

OSU = Oklahoma State University

PlainsGold = PlainsGold Seeds

TriCal = TriCal Superior Forage

Watley = Watley Seeds

WestBred = WestBred Wheat

 

  

Robert Calhoun

Senior Agriculturalist

 

Jeff Edwards

Department Head, Plant and Soil Sciences

 

Branden Watson

Graduate Research Assistant

 

Christopher Gillespie

Graduate Research Assistant