Our friends Dr. Thaddeus Gourd, Extension Director & Agent (Agriculture), Eric Hammond, Agent (Horticulture) and Cassey Anderson, Master Gardener Coordinator (Horticulture) from the Adams County Extension Office got in touch this week with the results from 2019’s Colorado onion seed trials.
And, Thad noted, the season is “one for the books!” He said, “The cool, wet weather delayed planting until April 10,” and the cool weather following planting also set the onions back.
But growers persevered, and the Extension Office thanked both the onion seed companies for participating and Bob and R.T. Sakata for again providing the venue for the trials.
“It is our hope that this research provides onion producers in Colorado with information to make educated decisions on variety selection based on environmental and pest conditions experienced here in Northern Colorado during the 2019 growing season,” Dr. Gourd wrote.
The single-trial site this year was north of Brighton, CO, and after the cool and wet spring, “weather conditions were favorable for growing onions,” Thad said. Temps spiked in July and August, and he said, “Little to no rain was recorded for the entire month of August, which is usually our monsoon season. The trial site used sprinkler irrigation.”
The evaluations performed this season included “emergence, thrips, pink root severity, fusarium basal rot infective levels, maturity and yield,” he continued. “Onion population evaluations occurred on July 7, 2019. Thrips populations were counted on July 25 and averaged 22.7 thrips per onion plant. The Iris Yellow Spot Virus (IYSV) assessment was taken on Aug. 29 and the disease incidence averaged 41.5 percent. The pink root severity and fusarium basal rot assessments were performed on August 29. This pink root disease pressure averaged 35.2 percent of roots infected and had a significant impact on onion yield. The percent of fusarium infected planted averaged 10.2 percent. Some varieties appeared to exhibit tolerance to the pink root and fusarium pathogens. Maturity data was taken on Aug. 20 and Aug. 29.”
The Onion Variety Trials Field Tour took place on Sept. 5, and harvest was done on Sept. 19. Onions were processed on Sept. 20, and Dr. Gourd reported that market yields “across all onion varieties averaged 13.3 tons per acre.”
The attached two tables summarize all evaluations performed for the 2019 Northern Colorado Onion Variety Trials. Onion storage assessments will take place during the second week of January. Contact Cassey Anderson at 303-637-8103 or cmanderson@adcogov.org or Thaddeus Gourd with comments or questions at 303-637-8117. You can visit the web site at www.adamscountyextension.org for 2019 onion variety trial results or see attachments below.
