Location: Forage Seed and Cereal Research UnitTitle: Susceptibility of grass cultivars to barley yellow dwarf viruses
|MERLET, LEA - Oregon State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/3/2019
Publication Date: N/A
Technical Abstract: Most cool season grass seed in the United States is grown in the Willamette Valley Oregon. In recent years, reduced stand performance has been observed in grass seed production fields. Many of these grasses are susceptible to Barley yellow dwarf viruses (BYDVs), which can cause red or yellowing of the leaf tips, stunting, reduced root mass, and yield losses, but may often be asymptomatic. The BYDVs are considered one of the most widespread and economically damaging virus diseases of major cereal crops. Previously, BYDVs have been reported to cause poor stand establishment, reduced competitiveness, and loss in productivity in perennial ryegrass pastures. Recently, surveys of seed production fields in the Willamette Valley were performed to determine if viruses might be contributing to stand decline. Three strains of BYDVs were found in perennial ryegrass fields; BYDV-PAV and Cereal yellow dwarf virus (CYDV) -RPV were reported in Fescue fields; and CYDV-RPV was found in Orchardgrass fields. Cultural practices, such as altering planting times to avoid aphids during early growth stages, or applying systemic insecticides at planting and foliar sprays to control aphids during peak flight times may help to reduce the impact of BYDVs in grass seed production fields; but insecticides are costly, environmentally unfriendly, and can be ineffective. The best long-term solution to disease management is arguably through host genetic resistance or tolerance to BYDVs or their vectors. Twenty-five varieties each of tall fescue, fine fescue, perennial ryegrass and orchardgrass are being evaluated for resistance or tolerance to BYDVs and CYDV. Varieties testing negative for BYDVs are being analyzed for the presence of endophytes. Identification of cultivars with resistance or reduced susceptibility to these viruses would be valuable for increasing stand longevity during seed production, and would also decrease potential virus reservoirs in grasses where other major food crops are grown.