Evaluation of Seed Treatments for Sweet Corn At Sixteen Locations in the United States

The Seed Treatment Committee of the International Sweet Corn Development Association (ISCDA) organizes a multi-location seed treatment trial every year. Researchers at locations across the U.S. evaluate the selected treatments for their effect on seedling stand establishment and vigor. Eighteen seed treatments and a nontreated control were evaluated in 2012 using a single seed lot of the sweet corn hybrid, Super Sweet Jubilee (sh2) (warm germination 84%, cold germination 70%). The seed treatments included mixtures of conventional, experimental, or organic fungicides, and many included seed enhancements and insecticides. The treatments were sponsored by five seed treatment companies. Additionally, two standard seed treatment mixtures and an organic treatment were selected by the committee. Sixteen sets of treated seed were sent to cooperating researchers at locations in seven states (FL, ID, IL, MN, NY, WA, and WI). Experimental design was a randomized complete-block with four replications. Planting dates ranged from February to September. Stand counts and vigor assessments were recorded at the 5–6 leaf stage. Data from each location were subjected to ANOVA and means were separated using the Fisher’s Protected Least Significant Difference (P = 0.05). Data from each location were then combined in a summary across locations, and analyzed with ANOVA and a comparison of the combined treatment means. The nontreated control and Treatment 12 (Organic Quick Roots) resulted in the smallest stand counts when averaged across locations, 47% and 49% respectively. It should be noted, however, that Treatment 12 did not include a fungicide, but was an organic seed enhancement product. Treatment 19 (Organic Champ Formula 2) also resulted in significantly smaller stand counts compared to the other seed treatments, only 54% when average across locations. However, Treatment 19 resulted in a significantly larger stand count compared to the nontreated control in the summary across locations. The other seed treatments resulted in mean stand counts ranging from 68% to 75% when averaged across locations. Overall, these treatments performed comparably to the two standard seed treatment mixtures in the trial. The treatment resulting in the largest stand count when averaged across locations was Treatment 17 (Metlock, Sebring, Rizolex, AP2, Signet, Captan, and Nipsit Inside) with a significantly larger stand count compared to all other treatments, except for Treatment 3 (Captan, Thiram, Dividend Extreme, Apron, Vitavax) and Treatment 10 (Maxim Quattro, Apron, Avicta Duo). A complete list of treatments, stand count results, and vigor results will be presented.