EFFET DU CLIMAT SUR LA FLETRISSURE BACTERIENNE DE LA POMME DE TERRE ET RELATION AVEC LE CONTENU EN SUCRES DES TIGES

Abstract

Potato cultivars resistant to bacterial ring rot, inoculated with Corynebacterium sepedonicum, were more infected in the northern regions (North Shore) than at La Pocatière (South Shore of St. Lawrence River) where the number of degree-days and mean temperatures are higher. Plant stems from the Northern regions had a higher total and reducing sugar content than those of La Pocatière and there was a significant correlation between sugar content and the mean temperature or the number of degree-days. However, the latter correlation is more significant than the one between the percentage of infected plants and the mean temperature or the number of degree-days in that region. The possible role of sugars in the disease evolution in the cool regions is discussed.