Response of oat, ryegrass, and barley infected with barley yellow dwarf virus to variation in nutrient supply

Abstract

Abstract Oat, ryegrass, and barley plants were grown in perlite with added nutrient solutions which varied in the Ca(NO3}2: KH2PO4 ratio. BYDV-infected ‘Clintland 60’ oats grown in high KH2PO4 produced yellow streaking symptoms on leaves. Virus infection delayed ear emergence and reduced fresh and dry weights, especially in high Ca(N03)2 and low KH2PO4. ‘Grasslands Ruanui’ ryegrass showed no BYDV symptoms on plants grown in a range of Ca(NO3)2: KH2PO4 ratios, although there was a significant reduction in yield of infected plants grown in high Ca(N03)2 and KH2PO4. The time of appearance of primary BYDV symptoms was later in resistant (CI 3926/3) than in susceptible (‘Kenia’) barley, both in winter and summer, and was little affected by varying the nutrient supply. Secondary symptoms were more severe in ‘Kenia’ than CI 3926/3 in summer, but less so in winter. Virus infection delayed ear emergence. The susceptibility of ‘Kenia’ and 4 Ethiopian cultivars (‘Abate’, CI 1227, CI 3926/3 and CI 9623) was compared. It is suggested that the time ofappearance and severity of primary leaf symptoms using a standard susceptible cultivar for comparison would provide a screening test for resistance to BYDV in barley.