ECONOMIC SIGNIFICANCE OF BARLEY STRIPE MOSAIC VIRUS IN THE CANADIAN PRAIRIES

Abstract

A method is described by which losses in seed yield due to barley stripe mosaic virus (BSMV) in commercially grown two-row barley (Hordeum distichum L. emend. Lam.) in the Canadian prairies were estimated. Commercial loss estimates were based on previously obtained survey data on the incidence of barley stripe mosaic (BSM) and experimentally determined yield losses for three cultivars of two-row barley inoculated with BSMV at the tillering stage. Based on studies conducted in several fields, a correction factor (1.5 × % plants with BSM symptoms) was used to account for probable symptomless infection by BSMV in surveyed fields examined at the tillering and jointing stages. Using this method, it was estimated that BSMV infection of two-row barley in southeastern Manitoba and southern Alberta accounted for combined yield losses of approximately 7,600 t (equivalent to about $0.8 million) in both 1974 and 1975. The possible nature of symptomless infection by BSMV is discussed.