STUDIES OF VIRUS DISEASES OF STRAWBERRIES IN BRITISH COLUMBIA: I. THE REACTION OF THE BRITISH SOVEREIGN VARIETY AND THE INDICATOR FRAGARIA VESCA TO YELLOWS

Abstract

British Sovereign, the commercial strawberry variety of British Columbia, has shown no field evidence of degeneration from the virus disease, yellows, that is attacking the Marshall variety in the Pacific Northwest. However, experimental inoculation of British Sovereign by stolon grafting to a yellows-infected Marshall plant proved the British Sovereign to be susceptible to yellows. As with the Marshall, infected plants were reduced in size and the foliage tended to flatten towards the grounds but, unlike the Marshall, there was no pronounced yellowing. When Fragaria vesca was grafted to a yellows-infected Marshall plant the reaction was rapid and severe. The older leaves flattened to the ground, the young runner tips hooked back, the newly developing leaves, though relatively well proportioned, were minute and yellow at the margins, and the plants eventually died.