Bouncing Back

By Dan Drost, Utah State University Photos by Dave Alexander, Publisher

Onion crop health and management approaches were the highlighted topics covered during the 2020 Utah Onion Association winter meeting held Feb. 11 in Brigham City, Utah. The growers had a lot to talk about as 2019 was a year of trials and frustrations. Most indicated that the late planting dates and generally poor finish to the year resulted in lower than expected yields and difficulties in storage.

Irrigation Issues

Cody Zesiger and Niel Allen, Utah State University (USU) irrigation specialists, reported on the 2019 Onion Water Use project.

“Utah House Bill 381 provided funding to assess applicable agriculture irrigation technologies to help Utah farmers save water while maintaining productivity and profitability,” Zesiger reported.

Onions were one of the crops chosen to document consumptive water use in drip- or furrow-irrigated fields. After describing the trial setup, Zesiger went on to highlight differences between the furrow- and drip-irrigated sites. He noted that in the furrow-irrigated field, “total application was quite high, with each irrigation delivering 5 to 6 inches of water. This resulted in both deep percolation and some surface runoff at the end of the field.”

In contrast, “drip used significantly less water, had no deep percolation or runoff, and had a calculated ET of 15 inches of water over the 70-day irrigation period,” he said.

While the two fields evaluated did not differ greatly in yield, they were not directly comparable as soil type, variety grown and harvest dates varied greatly. The study will be repeated in 2020 with additional field sites monitored. Findings will be shared with the industry at the summer field tour and again at the winter meetings.

Corey Ransom stresses the importance of pre-treatment with herbicides for yield at the Utah Onion Association winter meeting in February.

Stop the Rot

Claudia Nischwitz, a USU plant pathologist, provided the growers with two talks on onion disease management.

In her first presentation, she introduced the growers to the “Stop the Rot” project. In 2019, the USDA National Institute of Food and Agriculture funded Washington State University with $4 million to identify and manage bacterial diseases that impact onions in the field and storage.

Onions have a gate value of $925 million in the U.S. and are grown on more than 140,000 acres, and bacterial pathogens cause more than $60 million in losses to the industry each year.

Utah State University and the Utah Onion Association are participating in this project. During the 2020-2022 production seasons, USU researchers, in cooperation with interested local growers, will survey onion fields for bacterial diseases, identify pathogens found and then develop strategies to better manage them.

“With this study, Utah growers will now know what problems are out there and how to mitigate the risk both in the field and in storage. This should help improve onion sustainability and profitability,” Nischwitz said.

On the Lookout for Leafminers

In her second presentation, Nischwitz described USU efforts to identify and document the extent of leafminer injury in Utah-grown onions. Leafminer commonly found in Utah onion fields are Liriomyza and Hydrellia species. However, the extent of damage and impacts on productivity are less well known.

Nischwitz was able to secure a specialty crop block grant from the Utah Department of Agriculture and Food to monitor leafminer and create a sampling approach for detecting them. This work is to help create a system to address the more serious allium leafminer, should it arrive in Utah.

“Growers should be on the lookout for leafminer. While the allium leafminer is still only found in certain onion production areas of the eastern U.S., it may make it out west,” Nischwitz said.

To illustrate how this pest may arrive, she passed around a bunch of green onions purchased at a local grocery store. Leafminer tracks within the leaf blades were clearly visible.

“I’ve found live larvae in other samples, and the species present were leafminer commonly found in Utah onion fields,” Nischwitz said. “We need to be vigilant and prepared for the invasive, more damaging allium leafminer.”

Claudia Nischwitz warns growers in Utah to be on the lookout for allium leafminers.

Legislative Update

The meeting ended with Spencer Gibbons from the Utah Farm Bureau briefly outlining some of the key legislative issues in the 2020 Utah Legislature sessions. Of particular interest are those addressing water and water use. Gibbons encouraged onion growers to get involved so laws affecting them meet with their approval.

Dan Drost explains his study on plant emergence uniformity to meeting attendees in Brigham City, Utah.

Curtis Marble (far right) takes nominations for new Utah Onion Association board members. Dan Drost explains his study on plant emergence uniformity to meeting attendees in Brigham City, Utah. Stop the Rot

Gowan Seed Company displays Caldwell onions at the Utah Onion Association winter meeting.