HERMISTON, Ore. — Grass seed growers in the Columbia Basin, Grande Ronde Valley and Central Oregon this year are able to stay abreast of ergot spore production thanks to the introduction of an Ergot Alert Newsletter.
Detection of ergot spores in grass seed crops can help growers minimize the disease’s yield impact and avoid unnecessary fungicide applications, according to Union County Extension agronomist Darrin Walenta.
Walenta informed growers about the newsletter at a May 19 field day at the Hermiston Agricultural Research and Extension Center.
The newsletter is being put out by the Ergot Research Team, a group of Oregon State University and USDA Agricultural Research Service researchers. It contains spore-count data collected from traps that capture airborne spores at seven monitoring sites, and ergot management recommendations.
The first newsletter, issued May 13, reported that airborne ergot spores were collected at four sites, two in perennial ryegrass seed fields and two in Kentucky bluegrass seed fields. The first ergot spores were detected on April 19 and 22 in two Umatilla County perennial ryegrass fields. On April 26 and May 1, spores were detected in two Union County Kentucky bluegrass fields.
A second newsletter, issued May 18, reported that additional spores were counted in the two Union County bluegrass fields.
The second newsletter included an advisory that fungicide applications recently made for control of stripe rust and powdery mildew will not provide protection from ergot. Those applications, the alert states, were too early to provide ergot suppression.
The newsletter also states that no action is needed at this time (on May 18), because spore density is “very, very low and flowering has not begun yet.”
Grass seed crops are most susceptible to damage from ergot during flowering.
“However,” the newsletter states, “it is very important to monitor fields closely and track crop-development progress.” The alert also stresses the importance of timely fungicide applications and that growers should keep particularly close watch “in fields that had some level of infection in 2014.”
“If you had an issue in a field last year, prioritize your monitoring efforts there,” Walenta said at the field day, “because you know there will be inoculum in that field.”
The research team has been working to identify methods to manage ergot since OSU Extension plant pathologist Phil Hamm first formed it five years ago. The disease, considered one of the oldest known diseases of grasses and cereals, continues to create problems in grass seed crops, particularly in perennial ryegrass and Kentucky bluegrass seed crops, where it can lower yields and render straw unusable for animal feed.
The disease infects the flower of grass plants, which then exude a sticky substance referred to as honeydew, which attracts insects that spread the disease.
The disease eventually replaces seed with black fungal sclerotia.
Managing the disease takes a combination of cultural and chemical management, according to the May 13 newsletter. Among cultural management techniques recommended in the newsletter are to plant ergot-free seed and to rotate fields out of susceptible grasses.
The alert advises growers to consult the Pacific Northwest Plant Disease Management Handbook for fungicide products available for ergot suppression in Oregon and Washington.
At the field day, Walenta also encouraged growers to participate in an ergot survey that is designed to assess the value of the electronically distributed newsletter and to help identify more effective tools for ergot disease management.
Walenta asked growers to contact Jeremiah Dung at the Central Oregon Agricultural Research Center in Madras, 541-475-7107, for more information on the survey.