Trial Objectives and Procedures

Performance trials for hybrid grain sorghum are con-ducted by Oklahoma State University Extension each year. These trials provide producers, Extension educators, industry representatives and researchers with information for grain sorghum hybrids marketed in Oklahoma. Performance trials were conducted at nine locations in 2022. However, due to dry conditions at planting, the Adams, Homestead and Nardin locations were terminated. The only location that did not receive any irrigation throughout the season was Tipton. All other trials received supplemental irrigation to ensure the trial continued to survive. All trials, with the exception of Tipton, were planted within the timeframe that would be considered full-season. Due to early season dry conditions, the Tipton location was planted following a rain event in early June (which would be typical of double-crop systems). Trials at Chickasha, McCaull and Bixby were irrigated using overhead sprinkler irrigation. Supplemental irrigation was supplied to the Perkins location using a Rain Gun reel irriga-tion system. Goodwell location was irrigated with a mix of overhead sprinkler irrigation (at planting) and drip irrigation. Yields presented in this document are for the early, medium and late maturity hybrids for all locations. Most cultivars are similar among all locations. The exception to this is several early and medium cultivars, which are solely marketed to the panhandle region. Therefore, a number of cultivars are present in only the three panhandle locations.

Grain sorghum hybrid trial entrants (Table 1) were as-signed by companies to their respective maturity groups (early represented less than <60 days to mid-bloom (DMB), medium was 60 to 70 DMB, with late being 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, including tolerance to sugarcane aphids, are presented in Table 1. 

This information was not determined or verified by OSU. Company participation was voluntary; therefore, not all hybrids marketed in Oklahoma were included in the trials.

In 2022, 47 hybrids were entered by five seed companies (Table 1). For the hybrid performance trials, each maturity group was tested independently with individual hybrids be-ing 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 to OSU Extension best management practices for management. Soil samples were collected in the winter and early spring prior to planting and submitted to the Soil, Water and Forage Analytical Laboratory (SWFAL) 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 location this season were within reasonable limits (5.5-7.5). 

Growing Conditions

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 19). Test weight is also reported in pounds per bushel. Different plant populations at each loca-tion 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 vegeta-tive and early reproductive growth, will generally yield more than early and medium-maturity hybrids. The availability of moisture at critical crop development stages; however, 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 po-tential 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 esti-mate 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 CVs 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 ac-knowedged, as well as the efforts and resources provided by the producer-cooperators: Brook Strader, Brent and Anna Ballagh, Leon Richards and Kent Martin. The authors are also grateful for research support from Michael Pettijohn of SCREC, Mike Schulz of SWREC, Cameron Murley and Skeate Beck of OPREC, Butch Havener of MVRS and Erich Wehrenberg of CVRS. We are also grateful for the help of OSU Extension agricultural educators: Aaron Henson (Tillman County), Troy Gosney (Major County), Gus Holland (Tulsa County) and David Nowlin (Caddo County) who gave generously of their time to this project in 2022. 

Figure 1. Departure from average rainfall for April 2022.

Figure 2. Departure from average rainfall for May 2022.

Figure 3. Departure from average rainfall for June 2022.

  Figure 4. Departure from average rainfall for July 2022.

Figure 5. Departure from average rainfall in August 2022.

Figure 6. Departure from average rainfall in September 2022.

Figure 7. Departure from average maximum temperatures in July 2022.

Downstate Trials

Perkins

The Perkins location was planted during the first week of May into a field that had recently received a significant rain fall. It was during this rain event that the preplant herbicides were incorporated. Early stands were near perfect with excellent and even emergence. However, the trial experienced several rainfall events that left most of the trial area completely satu-rated with standing water for several days. This did decrease stands but because of the way the field was laid out, this primarily affected the fourth replication. The greatest overall impact of these early rainfall events was several flushes of weeds across the area. The weeds were manually removed early in the season. Due to persistent flushes, an application of Huskie was made in-season prior to canopy closure. As most of the weeds were between rows, applications were made with an in-row hooded sprayer to minimize impact on the growing plants (since they were beginning to stress with higher temperatures and drier conditions paired with early flooding events). Continued heat and moisture stress follow-ing flowering required irrigation in order to maintain the plots. Three 1-inch irrigations were applied with a reel gun irrigator. These irrigation events were applied at flowering, milk and soft dough. Even with these applications, sorghum prematurely matured and also resulted in later maturing cultivars not filling grain. Therefore, yields of the later-maturing cultivars were substantially lower than would be expected in a normal season. Chinch bugs were present early-season. Pyrethroids were applied to manage these but only achieved 40-50% control. These pests moved off by reproductive growth but due to the higher stress in-season, the impact of the chinch bugs was exacerbated this year compared to a normal year.

Cooperator: Erich Wehrenberg

Tillage Practice: Conventional
Soil Series: Dale Silt Loam
Seeding rate: 37,600 seeds/ac
Herbicide: Preemergence: 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
In-season: 16 oz Huskie in-season
Fertilizer: N- 140 lbs/ac
Planting Date: May 9
Harvest Date: August 24

Chickasha

The Chickasha location was originally planted the last week of April. However, due to excessive moisture during and immediately following emergence followed by overly warm conditions, stands were severely reduced and were highly variable. The trial was replanted three weeks later. After the replant, a similar issue occurred but the trial had only a slight decrease in stands but more importantly it occurred evenly throughout the trial. Early to mid-season weed pressure existed and weeds were manually removed. Beyond this, little weed pressure existed. Headworm pres-sure was present during early seed fill. A mix of pyrethroids and prevathon was applied in order to adequately control the pests. The trial was scouted in the trials the following weeks to make sure headworms were controlled and to check for sugarcane aphids.

Cooperator: Michael Pettijohn

Tillage Practice: Conventionally tilled
Soil Series: Canadian Fine Sandy Loam
Seeding rate: 37,600 seeds/ac
Herbicide: Burndown: 32oz glyphosate/ac
Preemergence: Charger Max ATZ 1.6pt/ac + 32oz glyphosate/ac
Fertilizer: N-120 lbs/ac, P-60, K-60
Planting Date: April 28/May 16
Harvest Date: September 9

Bixby

The Bixby location has continuously been used to demonstrate the potential of grain sorghum in typically corn-dominated portions of the state. However, even with supplemental irrigation, hot and dry conditions significantly decreased yield potential of this location. Furthermore, the lack of other potential food sources this year, bird damagewas higher this year than some others. However, yield was fairly consistent throughout. Limited pest management was needed at this location with no insecticides being applied. Weeds were not a major issue this season, due to adequate moisture early and irrigation to incorporate preplant herbicide applications paired with dry conditions following. The trial only needed minor spot weed management, which was removed manually. Because this location is typically rotated with soy-bean for several years, N rates for this location were much lower than other locations.

Cooperator: Butch Havener

Tillage Practice: Conventionally tilled

Soil Series: Wynona Silty Clay Loam
Seeding rate: 64,000 seeds/ac
Herbicide: Preemergence: 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
Fertilizer: N-40 lbs N/ac, 60 lbs P/ac, 60 lbs K/ac
Planting Date: May 16
Harvest Date: September 22
 

Tipton

While most seasons the Tipton location is one of the earliest trials planted due to early soil warming, the lack of rainfall did not allow for planting during what is considered an optimal full-season time frame. At this location, planting was delayed until June. A significant rain event occurred the first week of June, which allowed the crop to be planted shortly after. This could be used to simulate a double-crop or after an attempted cotton crop. From planting through the first of August, the plot received very little rainfall. Sporadic rainfall during the month of August kept the potential of harvesting this location as a viable option. This meant that a majority of the early maturing cultivars to have already filled grain and matured prior to these rainfall events. The maturity group that was able to take advantage of this rainfall were the later maturing cultivars and yields reflected these differences in maturity. While later-maturing cultivars are not common for double-crop or late planting situations, the longer-than-normal season typically experienced in this portion of the state means this could still be a viable option. Maturity was delayed until after the first major freeze, and harvest occurred several weeks afterward. Variability is relatively high for this location, this is also reflected in statistical significance values.

Cooperator: Mike Schultz and Gary Strickland

Tillage Practice: Conventionally tilled
Soil Series: Tipton Loam
Seeding rate: 64,000 seeds/ac
Herbicide: Preemergence: 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
Fertilizer: 40 lbs N/ac
Planting Date: June 9
Harvest Date: November 17

Pandhandle Trials

McCaull (Irrigated)

The McCaull site was the best location in 2022. This was not only because of the ability to irrigate the trial but it also experienced several timely rainfall events during the course of the season. As a result, temperature was the only factor limiting growth in-season. This is one of the primary reasons the variability of these trials were lower. This location is man-aged a little differently than some other locations. The field is strip-tilled a month prior to planting, with N fertilizer and initial application of herbicide being applied. Very little pest pressure was noted during the course of the season, so no insecticide was applied. Additionally, weed management was not an issue until later into the season where it was controlled through manual removal. Irrigation was applied continuously throughout the season, with the last application being made through soft dough.

Cooperator: Cameron Murley

Tillage Practice: Strip-till into corn residue

Soil Series: Gruver Clay Loam
Seeding rate: 66,000 seeds/ac
Herbicide: Preemergence: 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
Fertilizer: N-150 lbs N/ac
Planting Date: June 2
Harvest Date: November 1

Goodwell (Irrigated)

The Goodwell location is located at the Oklahoma Panhandle Research and Extension Center. The trial is managed under drip irrigation. However, this location did not get the more consistent rainfall events and the yields were lower than those achieved at the McCaull location. Additionally, this location had higher weed pressure and had to be hand weeded several times during the course of the year but was maintained weed-free otherwise. Similar to the McCaull location, the trial location was strip tilled with N applications and the initial preplant herbicide application was applied at the same time.

Cooperator: Cameron Murley

Tillage Practice: Strip-tilled
Soil Series: Gruver Clay Loam Seeding rate: 66,000 seeds/ac
Herbicide: Preemergence: 1.6 qt/ac Charger Max ATZ + 32oz glyphosate/ac
Fertilizer: N-100 lbs N/ac applied through the strip-till unit
Planting Date: June 2
Harvest Date: October 25