Corn Performance Trials in Oklahoma Panhandle, 2021

Trial Description

A corn hybrid trial was conducted at the Oklahoma Panhandle Research and Extension Center, Goodwell, OK. A total of 38 hybrids belonging to 5 seed companies (Table 1) were included in the trials. These trials are conducted to evaluate the performance of corn hybrids marketed in the Oklahoma Panhandle and adjacent areas as well as to provide unbiased information on performance of hybrids to extension educators, farmers, and the seed industry and dealers. The Oklahoma Panhandle is a semi-arid area with a long-term mean annual rainfall of approximately 17 inches. It should be noted that corn hybrid performance varies with climatic conditions, and this trial represents corn performance in semi-arid conditions of Oklahoma Panhandle. Climate data and an overview of growing conditions is presented in following sections of this report.

The field was strip tilled during the first week of April. The soil sample analysis report showed approximately 67 lbs of residual N in top 18 inches. Additional fertilizer was applied in the form of 32-0-0 (Urea ammonium nitrate or UAN) during strip tilling to bring available N levels to 250 lbs per acre. Two row plots of 150 feet length were planted for each hybrid on April 29, 2021. A starter fertilizer (10-34-0 or diammonium phosphate) was applied at planting at the rate of 5 gal/acre. The trial was conducted using a randomized complete block design with three replications. The crop was planted with a tractor powered John Deere two-row cone planter at 2.5 inch depth, 30-inch row spacing and at 28,000 plants per acre. Plots were harvested with the Kincaid 8XP two row plot harvest combine on October 8, 2021. The crop was irrigated through lateral irrigation system fitted with sprinkler nozzles. Weeds were controlled using pre- and post-emergence herbicides. However, no major weeds or insect issues were noticed in the field. The average yield of the hybrid trials at OPREC in the prior year (2020) was 176 bushel per acre.

 

Table 1. Participating seed companies and their contacts.

 

Growing Conditions

The growing conditions in 2021, remained conducive for corn for the majority of the growing season. Figure 1 shows, that average daily air temperature dipped below the long-term average for a significant number of days in May and June. In fact, the air temperature remained below long-term average during the last week of June and the first week of July. This time-period was in synchrony with onset of reproductive (tasseling and silking) stages of the crop. The cumulative rainfall during growing months (May-August) remained close to long term averages. The cumulative rainfall received during this period was 9.4 inches, approximately equal to the long-term average of 9.6 inches for this period. Inclement conditions persisted towards the end of August and September which hit the crop with high temperatures and high-speed winds. At this point, the crop had already entered the denting stage, which reduced any significant impact of inclement weather towards the end of the growing season. The air temperature below normal during critical stages of crop growth resulted in low ET demand despite the low rainfall during the growing season.

 

Figure 1. Daily average temperature at Goodwell Mesonet station in 2021 along with long-term average, maximum, and minimum temperatures (source: Oklahoma Mesonet).

 

Figure 2. Daily rainfall amounts during growing season recorded at Goodwell Mesonet station (source: Oklahoma Mesonet).

 

Data Analysis

Harvest data included yield, moisture at harvest and test weight. The yield (Table 2) was adjusted to 15.5% moisture level for all the hybrids. The data was analyzed using SAS 9.4 software. The least significant difference (LSD) was used to determine difference between performance of hybrids. The LSD is the minimum difference between yield of two hybrids to consider them different in terms of performance. For example, if LSD is 10 bu, the difference in average yield of two hybrids is less than LSD indicates that the hybrids have performed similarly, whereas in case the difference among yields was greater than LSD, then the hybrids have performed differently. The difference in hybrids despite similar performance due to LSD, could be due to random factors including soil, moisture or fertility etc. The LSD for this trial is provided with the results table. Coefficient of variance (CV) was calculated to measure the variation of yield data from the mean yield. A CV greater 20% indicates high variation which usually correspond to unreliable data. The mean yield for this trial was 215 bu/acre, with CV of 8.3% and LSD of 41.

 

Results

Table 2. Comparison of the 37 corn hybrids tested at OSU Panhandle Research and Extension Center in 2021.

* Not statistically different from highest yielding hybrid (p<0.05)

 

Acknowledgements

We would thank support staff of Oklahoma Panhandle Research and Extension Center, especially Scott Robertson and Luis Figueroa for their help in conducting this trial. Also, we would like to thank the seed companies who participated in this trial. We also would like to thank Britt Hicks, Loren Sizelove, and Justin Wagner for their support in our extension program.

 

Questions can be directed to Sumit Sharma at sumit.sharma@okstate.edu or at (580) 349-5440.