The 2020 UCCE Delta field corn variety trial, located on Tyler Island, was planted on April 21st by air planter and consisted of three replicate blocks of seventeen varieties. The seventeen varieties included fourteen varieties submitted by seed companies and three submitted by the grower. All varieties were glyphosate tolerant. Over the course of the season, we evaluated stand count, bloom, disease incidence (Fusarium ear rot, head smut, common smut; Fig. 1), lodging, and yield. The field was harvested on September 25th.
Table 1 presents mean values for the three replicates. The statistical method used to compare the means is called the Tukey's range test. Varieties were considered statistically different if their P value was less than 0.05, or 5 percent. Twelve varieties have a letter “a” following their mean yield, which means that those twelve varieties all yielded similarly in the trial.
In addition to yield, there were also statistical differences among varieties in Fusarium ear rot, head smut, common smut, ear height, grain moisture, and bushelweight. The CV, or coefficient of variation, is the standard deviation divided by the mean, or a measure of variability in relation to the mean. For the diseases, the variability among the three replicates was very high.
For a printable report with more description of the trial, please visit my website. Special thanks go to the cooperating growers, Gary and Steve Mello, and the participating seed companies.
Figure 1. Diseases monitored in the UCCE Delta field corn variety trial: A) Fusarium ear rot, B) head smut, and C) common smut. These three diseases are generally managed by variety selection.
Table 1. 2020 UCCE Delta field corn variety trial results. Results for each variety are expressed as the average across three replications.
* Data were transformed for analysis. Arithmetic means are presented.
‡ Yield adjusted to 15% moisture.