Incidence of barley yellow dwarf virus in ryegrass pastures in New Zealand

Abstract

The percentage of plants infected with barley yellow dwarf virus (BYDV) was determined in each of 45 New Zealand ryegrass pastures during the summer of 1975–1976. Incidence of BYDV infection was extremely variable in pastures of similar age, but 1- to 2-year-old pastures generally had fewer infected tillers than did older swards. Many 6- to 30-year-old pastures had over 50% of plants infected with BYDV. Highest virus infection was 84% in two perennial ryegrass pastures aged 8 and 15 years. Pastures at Palmerston North had a slightly higher incidence of BYDV than those at Kaikohe and Lincoln. Pastures in the far south of the South Island appeared to have a low incidence. © 1977 Taylor & Francis Group, LLC.