POCATELLO, Idaho — The Idaho potato industry is mulling required bacterial ring rot testing of early generation seed, as well as new record-keeping standards to better trace infections back to a point of origin.
A group of about 35 industry representatives has been meeting for several months to address their state’s ongoing challenges with the disease, which can be financially devastating to growers.
Michael Cooper, with the Idaho State Department of Agriculture’s Plant Industries Division, used their input to draft proposed regulations, which the group reviewed and revised Jan. 24 in Pocatello.
Idaho Potato Commission President and CEO Frank Muir said the goal is to enact flexible, temporary rules for the upcoming season, followed by final rules later.
“The objective of this is to make sure we’re working toward a feasible, long-term approach to resolving bacterial ring rot,” Muir said.
To catch ring rot early enough to prevent further spreading but not so early that its presence may be undetectable, group members have been leaning toward testing G2 seed — or seed in the third year of field planting. About 15 Idaho seed growers raise G2 seed, selling mostly to other seed growers who replant it for one or two more generations and sell to commercial growers.
Another challenge will be agreeing upon the ideal tuber sample size for the required test.
The group is also working to establish a cooperative program between ISDA and the Idaho Crop Improvement Association to trace back infections, Muir said.
Ring rot is a zero tolerance disease, meaning a single positive plant in a field is cause for the immediate rejection of a seed lot. In Idaho, any detection also means growers can’t replant seed from any other lots to produce more seed, forcing them to clean all equipment and buildings and start with all new seed.
Idaho Crop Improvement Area Manager Alan Westra said the vast majority of seed growers are already seeking ring rot testing to satisfy their customers and major processors.
According to results of commercial field testing done late this summer at the University of Idaho’s Kimberly Research and Extension Center, of 40 fields tested, 26 fields and seven potato varieties tested positive.
Idaho Potato Commissioner Ritchey Toevs, of Aberdeen, had his seed tested for ring rot this season and said he “strongly supports lab testing for BRR rather than just visual inspection.”
“We don’t have a pandemic. It’s more of a proactive move,” Toevs said of the proposed changes.
Emma Atchley’s seed farm in Ashton produces seed tracing all the way back to the prenuclear stage — grown directly from plants made with tissue cultures. She believes the cost of required testing pales in comparison with the money that the industry stands to save.
“It’s the most proactive step that has probably ever been taken by a seed system to address the issue,” Atchley said of the proposal. “We feel very good that growers have agreed that’s the way to go.”