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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #246001
Title: Monitoring of ergot (Claviceps purpurea) ascospore release to better time fungicide application in NE Oregon grass seed production

Author
item WALENTA, D - Oregon State University
item HAMM, P - Oregon State University
item Alderman, Stephen

Submitted to: Seed Production Research at Oregon State University
Publication Type: Experiment Station
Publication Acceptance Date: 2/28/2009
Publication Date: 3/31/2009
Citation: Walenta, D.L., Hamm, P.B., Alderman, S.C. Monitoring of ergot (Claviceps purpurea) ascospore release to better time fungicide application in NE Oregon grass seed production. Seed Production Research at Oregon State University. 2009. p. 34-38.

Interpretive Summary: Ergot, caused by Claviceps purpurea, is an important floral infecting and seed limiting disease of Kentucky bluegrass. Spore traps were used to determine the timing and release of spores of C. purpurea. In 2008, spore production preceded the susceptible flowering stage in Kentucky bluegrass, resulting in little to no infections. This study suggests that savings of up to $60 an acre are possible, based on knowledge of the timing and occurrence of ergot spore production.

Technical Abstract: Ergot, caused by Claviceps purpurea, is an important floral infecting and seed limiting disease of Kentucky bluegrass. Regional differences in ergot occurrence in Kentucky bluegrass and perennial ryegrass have been observed in grass seed production areas near Hermiston and near La Grande, OR. This study was conducted to 1) determine whether differences in ergot severity were due to primary spore production or other factors and 2) whether fungicide efficacy could be improved by timing fungicides to spore release. Burkard 7-day volumetric spore traps were used to monitor spores (ascospores) of C. pupurea in a Kentucky bluegrass and perennial ryegrass field near Hermiston and in two Kentucky bluegrass fields near La Grande, OR. In 2008, ascospore release preceded flowering in the grasses, resulting in few infections during the susceptible flowering stage of the grasses. The results suggest that one or more fungicides for ergot control were not warranted in 2008, representing a savings of up to $60 an acre.