PARMA, Idaho — A researcher is leading a major project that seeks to help bulb onion growers in this region reduce the impacts of soil-borne diseases.
Soil-borne diseases of onions grown in the Treasure Valley region of Idaho and Oregon, especially pink root, can reduce yields by up to 40 percent.
“Soil-borne diseases are a considerable constraint on onion production,” said University of Idaho Plant Pathologist James Woodhall, who is based at the university’s agricultural experiment station in Parma.
He received a $109,000 specialty crop grant from the Idaho State Department of Agriculture for the project.
While onions are the region’s cash crop, it is also expensive to grow them, with production costs of about $4,000 an acre.
“Therefore, stakeholder losses from diseases can be great,” states Woodhall’s grant application. “To be economically competitive, growers must produce high yields of large-sized onions. However, soil-borne diseases can be a considerable constraint to production.”
They’re also difficult to control and Woodhall’s project seeks to develop best management practices to control soil-borne diseases in onions.
Brian Taylor, a farm manager and chairman of the Idaho-Eastern Oregon Onion Committee’s research committee, said the project holds promise for the region’s 300 onion growers, especially when it comes to controlling pink root.
“Pink root definitely is a problem and it’s getting worse on some of the older, tireder ground,” he said. “I think this project should be quite beneficial to us.”
Bob Simerly, an agronomist with McCain Foods, a large processor of onions from the region, said the pink root problem in the area “is somewhere between gigantic and huge. It’s a really bad disease.”
He said Woodhall’s project “should be really helpful, especially with regard to pink root. We’ll cooperate with him in anything he needs because it’s a really important issue to us.”
Woodhall’s project will include looking at fungicide and bio-pesticide-based alternatives to fumigation, an expensive option widely used on onion fields in the region.
Woodhall said developing new ways to determine the soil health of an onion field will be a major part of the research project and next-generation techniques will be used to sequence the DNA of all microbes in a sample.
It might turn out that some of the soil contains an onion disease but also material that suppresses the disease, which means it might not be necessary to fumigate that field, he said.
“Increasing yields and reducing unnecessary treatments are the two main ... focuses of the project,” Woodhall said.
The project will monitor 100 onion fields in the region, from pre-planting to harvest.