Trial Objectives and Procedures 

Performance trials for hybrid grain sorghum are conducted by Oklahoma State University Extension each year. These trials provide producers, Extension educators, industry representatives and researchers with information about grain sorghum hybrids marketed in Oklahoma. Performance trials were planted at eight locations in 2024. All emerged and had decent early season growth. However, due to dry conditions at planting, the Homestead location was terminated. Trials at Chickasha, McCaull and Goodwell were irrigated using overhead sprinkler irrigation Yields presented in this document are for the early, medium and late-maturity hybrids for all locations. Most cultivars were grown at all locations. The location at Fairfax was conducted with a cooperator who had previously grown wheat, and the sorghum trial was planted as a double-crop system.

Grain sorghum hybrid trial entries were assigned by companies to their respective maturity groups: early represented less than 60 days to mid-bloom (DMB), medium was 60 to 70 DMB,and late was > than 70 DMB). If a cultivar was exactly 60 or 70 DMB, previous years' data was used to determine which maturity the cultivar fell into. Companies designated all hybrid characteristics, which are presented in Table 1. This information was not determined or verified by Oklahoma State University. Company participation was voluntary, so not all hybrids marketed in Oklahoma were included in the trials.

In 2024, 35 hybrids were entered by five seed companies. For the hybrid performance trials, each maturity group was tested independently with individual hybrids being arranged in a randomized complete block design and having a minimum of four replications. All locations were two row plots with 30-inch spacing and 35 feet in length. Plots were trimmed to 25 feet prior to harvest. Tractor-powered cone planters were used to plant all trials with seeding rates adjusted for the trial location. Trials were harvested with a Kincaid model 8XP plot combine.

Planting densities, cooperating producers, cultural practices, soil series, herbicides and insecticides used in all trials are listed individually in result tables. Rainfall data from the nearest Mesonet sites are also listed. Some trials are long distances from the nearest Mesonet site; therefore, rainfall could be greater or less than reported.

Soil fertility practices will be discussed for each individual location following their yield tables. All applications were made in accordance with OSU Extension's Service best management practices. Soil samples were collected in the winter and early spring prior to planting and submitted to submitted to OSU's Soil, Water and Forage Analytical Laboratory for analysis. All N, P and K applications were made based on these results. Nitrogen applications were made based on a 120 bu/ac yield goal with the exception of Goodwell and McCaull, which were made based on a 150 bu/ac yield goal. At all research station sites, soil pH is managed to be suitable for grain sorghum production. Locations on grower's fields are not as controlled; however, all locations this season were within reasonable limits (5.5-7.5).

Due to the degree of variability between the sites in the study and grower's fields around the state, discussions regarding the growing conditions will be made prior to each individual location.

Results 

Grain yields are reported in pounds per acre and bushels per acre of threshed grain, adjusted to a moisture content of 14% (Tables 2 through 21). Test weight is also reported in pounds per bushel. Different plant populations at each location prevent accurate comparison between locations. Also, comparisons across maturity were not conducted as they were treated as independent trials. Producers should note that late-maturing hybrids, due to longer periods of vegetative and early reproductive growth, will generally yield more than early and medium maturity hybrids. However, the availability of moisture at critical crop development stages often influences yield more than the yield differences associated with maturity groups. When choosing a maturity group, the type of cropping system, planting date, planting rate and potential moisture should be taken into consideration. For more information, consult Fact Sheet PSS-2034 Grain Sorghum Planting Rates and Dates and Fact Sheet PSS-2113 Grain Sorghum Production Calendar.

Least significant difference (LSD) is a statistical test of yield differences and is shown at the bottom of each table. Unless two hybrids differ by at least the LSD shown, little confidence can be placed in one hybrid being superior to another, and the difference is probably not real.

The Coefficient of Variation (CV) is provided as an estimate of the precision of the data with respect to the mean for that location and maturity group. To provide some indication of yield stability, multi-year means for yields and test weights are provided where trials have been conducted for more than one year with more than three entries per maturity group. Producers interested in comparing hybrids for consistency of yield in a specific area should consult these entries. Models with CV's greater than 25 have not been included in this report.

Acknowledgements 

The financial support of the participating companies and the Oklahoma Sorghum Commission is gratefully acknowledged, as well as the efforts and resources provided by producer cooperators Brook Strader and Brandon Keeler. The authors are also grateful for research support from Michael Pettijohn of SCREC, Mike Schulz of SWREC, Cameron Murley of OPREC, Ted Newell of MVRS and Kenneth Watkins of CVRS. We are also grateful for the help of County Agricultural Educators: Martha Keasler (Tillman County), Shelby Robertson (Major County), Hannah Hough (Tulsa County) and Kelly Burrows (Grady County), who gave generously of their time to this project in 2024.

Figure 1. Average maximum air temperature for April 2024.

Figure 2. Average maximum air temperature for May 2024.

Figure 3. Average maximum air temperature for June 2024.

Figure 4. Average maximum air temperature for July 2024.

Figure 5. Average maximum air temperature for August 2024.

Figure 6. Average maximum air temperature for September 2024.

Figure 7. Average maximum air temperature for October 2024.

Figure 8. Departure from average temperature for October 2024.

Figure 9. Departure for average rainfall from April 2024.

Figure 10. Departure for average rainfall from May 2024.

Figure 11. Departure from average rainfall for June 2024.

Figure 12. Departure from average rainfall for July 2024.

Figure 13. Departure from average rainfall for August 2024.

Figure 14. Departure from average rainfall for September 2024.

Figure 15. Departure from average rainfall for October 2024.

Chickasha 

The Chickasha location experienced a relatively normal year. Early excessive moisture did not allow for tilling and smoothing of the field until much later than intended. The trial was planted well outside the typical planting period for either early season or late season production. A flush of weeds during the late vegetative period through the early reproductive period did require addressing. Since there were primarily grasses, they have to be physically removed through hand weeding. Compared to normal years, the incidents of wildlife (both deer and bird) damage was relatively low, which resulted in better yields and more consistent yields throughout the trial. Additionally, no further insect pests were noted throughout the year, so no insecticides were applied this season. Above average heat and continued dry conditions led to a more rapid dry-down than normal, which resulted in a week or two earlier harvest than expected. It was thought that this might have decreased yields, but yields were still average to above-average for this location. A decrease in test weight was seen, especially for the early and several of the medium cultivars. While the later hybrids also had lower test weights than we would like to see, they were consistently higher than either the early or medium maturity cultivars.

Cooperator: Michael Pettijohn
Tillage Practice: Conventional tilled
Soil Series: Dale Silt Loam
Seeding rate: 55,000 seeds/ac
Herbicide: Preemergence 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
Fertilizer: N- 140 lbs/ac
Planting Date: May 24
Harvest Date: Sept. 9

Tipton

This trial was planted into terminated wheat residue; therefore, a slight delay was experienced compared to other growers in the area. Between the pre-plant herbicide program and the wheat residue, very few weeds were present early on. Additionally, due to higher moisture and wheat residue, early growth was slower and more delayed than normal. Smaller broadleaves and some sandburs were present later in the season; however, this was beyond typical herbicide application windows, so these were managed with hand weeding. There was virtually no impact from insects throughout the season, so no insecticides were applied. Because of earlier planting and higher than normal temperatures, harvest was earlier than normal (one to two weeks earlier than expected). Due to the dryland system and relatively delayed early-season growth, yields were much lower than typical for this location. However, these yields were not lower than the average yields experienced by dryland producers in the region.

Cooperator: Mike Schultz
Tillage Practice: No-till into wheat residue
Soil Series: Tipton Loam
Seeding rate: 55,000 seeds/ac
Herbicide: Preemergence 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
Fertilizer: N- 140 lbs/ac
Planting Date: April 22
Harvest Date: Aug. 13

Perkins 

The Perkins location was at the Cimarron Valley Research Station near Perkins, Oklahoma. The previous crop was a mix of soybean agronomic trials from the previous year; however, none had a significant impact on trial variability. The trial was planted into a tilled field. The field was tilled the previous winter, which allowed the crop to be planted early. Drier conditions following planting resulted in the pre-plant herbicide program not activating efficiently, which resulted in several weeds early in the production season. These were a mix of broadleaf and grassy weeds; therefore, they were managed twice in-season by hand weeding practices. A small flare up of sorghum aphids were noted, but this population crashed prior to an insecticide application. A larger outbreak of chinch bugs was experienced during post flowering through early grain fill. Unlike normal, these were not present in lower canopy or collar regions but on the flag leaf and in the panicle. These were managed through a Lambda-cyhalothrin application (as Besiege®). Similar to other locations, dry late-season conditions resulted in quicker dry-down conditions. This can be seen by the lower-than-average test weight.

Cooperator: Kenneth Watkins
Tillage Practice: Conventional
Soil Series: Teller Fine Sandy Loam
Seeding rate: 55,000 seeds/ac
Herbicide: Preemergence 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
Insecticide: 10 oz/ac Besiege applied post-flowering for chinch bugs in the head and upper canopy
Fertilizer: N- 140 lbs/ac; P- 60 lbs/ac; K- 60 lbs/ac
Planting Date: May 3
Harvest Date: Sept. 8

Bixby 

The Bixby location is the program's only eastern Oklahoma location, which often has more stable temperatures and consistent rainfall patterns. This allows for a different look at cultivar performance under these conditions. In 2024, Bixby was not exempt from hot and dry conditions; however, the location experienced substantially higher temperatures and lower in-season precipitation than normal for this location. Early excessive moisture early lead to limited ability to till the ground early and apply a preplant herbicide program. Therefore, this was applied at planting. The dry conditions that followed limited efficacy of this program. This location is noted for having heavy pigweed and grass pressure. Grasses were not an issue throughout the growing season with only minor issues of a patch of Bermudagrass located in the early maturing cultivars in the third replication. This was managed through physical removal but did cause slight reductions in yields and increased variability. However, since the pressure was consistent across the early cultivars, this replication was maintained for analysis. The major weed of the location was pigweed. These were managed with an application of Huskie and physical removal.

No major insect issues were noted during the course of the season. While this location can be irrigated, no irrigation was applied due to mechanical issues with the irrigation pump; therefore, this should be considered a completely dryland trial in 2024. No significant diseases were present throughout the season. Recent research has also shown that N applications do not have to be as high at this location as it often follows several years of soybean.

Cooperator: Ted Newell
Tillage Practice: Conventional
Soil Series: Wynona Silty Clay Loam
Seeding rate: 55,000 seeds/ac
Herbicide: Preemergence 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac 16 oz/ac Huskie at 5-leaf stage
Fertilizer: N/A
Planting Date: May 29
Harvest Date: Sept. 26

Fairfax

This trial was on a grower field (Brandon Keeler) north of Fairfax. This trial was planted following wheat harvest, making it a double-cropping system. A traditional preplant herbicide system was sprayed. A rainfall within a week after application and planting resulted in high efficacy of the program. Weeds were not a problem in the trial throughout the season. Pressure from both sorghum aphid and chinch bugs were present during the growing season but did not persist long enough for an application to be made for either. This location was the most impacted by the hot and dry conditions during the late-summer and early-fall period. Harvest of the crop was nearly one month earlier than it should have been. While yields were not much lower than to be expected with double-crop production in dryland systems, yields were lower than expected in-season as well as lower test weights. Statistical analysis was not conducted on the medium-maturity cultivars due to the high amount of variability associated with the trial. This was primarily due to deer predation on the fourth replication of the trial.

Cooperator: Brandon Keeler
Tillage Practice: No-till behind wheat (double-crop)
Soil Series: Norge silt loam/Wynona silty clay loam
Seeding rate: 55,000 seeds/ac
Herbicide: Preemergence: 1.6 qt/ac Charger Max ATZ+32 oz/ac glyphosate
Fertilizer: N/A
Planting Date: June 12
Harvest Date: Oct. 10

Goodwell 

The Goodwell location was at the Oklahoma Panhandle Research and Extension Center and was under an overhead sprinkler irrigation system. The trial was strip tilled into the previous year's wheat crop. The trial was fertilized through the strip-till unit. The location had adequate moisture before planting as well as good moisture following; therefore, emergence was not an issue, and an adequate stand was achieved. A major storm hit the trial at the early vegetative stage. The primary issues with this storm were excess rainfall and hail. This did damage to the plants, but they fully recovered prior to the grand growth period. Adequate weed control was done throughout the season using hand-weeding techniques. A minor sorghum aphid outbreak occurred in the sorghum surrounding the trial but was never in the trial. Therefore, no insecticide applications were applied. The two panhandle locations were the only trials that did not suffer the impacts of the hot and dry conditions. This was primarily due to the abundance of moisture experienced throughout the primary production season. Harvest was several weeks earlier than expected, primarily due to hotter-than-average conditions through late September and most of October. However, compared to the other downstate locations, these conditions did not seem to negatively impact yields or test weights.

Cooperator: Cameron Murley
Tillage Practice: Strip-tilled into wheat residue
Soil Series: Gruver Clay Loam
Target Population: 55,000 seeds/ac
Fertilizer: 200 lbs N/ac, 65 lbs P/ac
Planting Date: May 21
Harvest Date: Oct. 31

McCaull 

The trial location was at the McCaull Research and Demonstration Farm near Elkhart, Kansas. The trial was strip-tilled into previous wheat crop residue. All fertilizer was applied in the strip. The trial was irrigated with overhead sprinkler irrigation and was on the inner irrigation spans of a quarter acre pivot with the outer spans planted to corn. With rainfall and irrigation applied before planting, soil moisture at planting was more than adequate. This resulted in very good stands shortly after planting. However, with the associated moisture, early flushes of weeds were present. These were primarily bindweed mixed with sporadic pigweeds. Due to periodic moisture and rapid early growth, auxin herbicide could not occur. These had to be controlled through manual removal. Irrigation and timely rainfall limited stress throughout the season. Similar to other locations, hotter-than-average conditions resulted in more rapid dry-down. However, yields and test weights were not impacted by these conditions. No insect or disease pressure was experienced throughout the trial period.

Cooperator: Cameron Murley
Tillage Practice: Strip-tilled into wheat residue
Soil Series: Gruver Clay Loam
Target Population: 55,000 seeds/ac
Fertilizer: 200 lbs N/ac; 65 lbs P/ac
Planting Date: May 22
Harvest Date: Oct. 30