Fall Forage Production and First Hollow Stem Date for Wheat Varieties During the 2024-2025 Crop Year

Introduction

Fall forage production potential is one of the major considerations in deciding which variety to plant. Dual-purpose wheat producers may find varietal characteristics, such as grain yield after grazing and disease resistance, to be 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, fall forage production is a selection criterion that should be considered. For more information on variety characteristics, 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 wheat forage production potential and grazing duration among the most popular varieties grown in Oklahoma. Management factors, such as planting date, seeding rate and soil fertility, are very influential and sometimes more important than variety selection in determining forage production. Environmental factors, such as rainfall amount and distribution and temperature, also play a large role in dictating how much fall forage is produced. All 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 the fall forage variety trials is to give producers an idea of the fall forage production ability of wheat varieties commonly grown throughout Oklahoma. The forage trials were conducted under Oklahoma State University’s Small Grains Variety Performance Trials. During the 2024–2025 growing season, forage trials were conducted at the Chickasha and Stillwater test sites. Additionally, first hollow stem measurements were collected at both sites in 2025. Weather data for each location are provided in Figures 1 and 2.

 

 

Figure 1. Average daily temperature (line graph) and rainfall (bar chart) from Oct. 1, 2024 to March 31, 2025, at Stillwater. Weather data courtesy Oklahoma Mesonet.

 

 

 

Figure 2. Average daily temperature (line graph) and rainfall (bar chart) from Oct. 1, 2024 to March 31, 2025, 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. At planting, 5 gallons per acre of 10-34-0 was applied in seed furrow at Stillwater and Chickasha. Due to severe drought conditions at planting, 0.5 inches of irrigation were applied on Oct. 7, 8, 9 and 17 in Stillwater to support seed germination and emergence. The seeding rate at both locations was 120 pounds per acre. Forage was measured by hand clipping two, 1-m 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 (Table 1). All samples were placed in a forced air dryer after collection for approximately seven days and weighed. Fertility, planting date and forage sampling date information is provided in Table 1.

 

Notes: STP: soil test P index; STK: soil test K index

 

 

The Stillwater trial included both ungrazed and simulated grazed plots, while the Chickasha trial consisted of ungrazed plots only. In the simulated grazing treatment, plants were mowed to a height of 2.5 inches on Jan. 3, 15 and 28 as well as Feb. 10 and 28 and March 6 and 12. First hollow stem sampling began at the end of January at both locations and was conducted every three to four days by variety until all varieties reached first hollow stem. Plant samples were collected for each variety by digging an 8-inch section of row and selecting 10 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 10 plant samples was 1.5 cm (5/8 inch) 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 2024–2025 fall forage production season was marked by moderate temperatures and extremely low rainfall. The irrigation applied shortly after planting helped with crop establishment and enabled the crop to take advantage of the rainfall that arrived later in October. This contributed to the moderate level of fall forage production observed in our fields in Stillwater. The average fall forage production at Stillwater was 1,473 lbs/acre, and values ranged from 984 to 2,070 lbs/acre (Table 2). Average forage production at Chickasha was 2,175 lbs/acre, and values ranged from 1,734 to 2,609 lbs/acre (Table 3).

 

Notes: Bolded values are not statistically different from the highest-yielding variety within a column. Em-dashes "—" = data not available.

 

 

Notes: Bolded values are not statistically different from the highest-yielding variety within a column. NS; no statistical differences were detected among varieties within a column. Em-dashes "—" = data not available.

 

 

First hollow stem data are reported in day of year (day) format for the winter wheat varieties in Table 4. To provide a reference, keep in mind that March 1 is day 60. The fall and winter months were characterized by dry conditions in Stillwater with temperatures somewhat normal. Supplemental irrigation helped crops to emerge by mid-October (later than usual, but earlier than many places under drought in the state) and resulted in good plant development. The average winter wheat first hollow stem date at Stillwater ungrazed plots was day 77 (March 18). This was 29 days later than 2024 (Feb 17), eight days later than 2023 (March 10) and 12 days later than the 20-year average (March 6). There was a 18-day difference between the earliest and latest varieties at Stillwater compared to a 21-day difference in 2024 and 14-day difference in 2023. The average winter wheat first hollow stem date for the Chickasha location was 72 (March 13). This was 14 days later than 2024, one day later than 2023 (March 12) and seven days later than the 20-year average (March 6). There was a 14-day difference between the earliest and latest varieties at this location compared to a 13-day difference in 2024 and 11-day difference in 2023.

 

 

 

Acknowledgements

The authors would like to thank the Oklahoma Wheat Commission and the Oklahoma Wheat Research Foundation for providing partial funding for this research as well as to undergraduate students Lettie Crabtree, Camila Bayer and Francisco H. Aispuro Arana for their assistance with forage sampling collection and first hollow stem measurements.

 

Seed Sources and Abbreviations

• AgriPro = AgriPro|Syngenta Seeds
• AGSECO = AGSECO Inc.
• KWA = Kansas Wheat Alliance
• LCS = Limagrain Cereal Seeds
• OGI = Oklahoma Genetics Inc.
• OSU = Oklahoma State University
• PlainsGold = PlainsGold Seeds
• WestBred = WestBred Wheat