BEHAVIOR OF SOME APPLE VARIETIES GROWN UNDER SUPERINTENSIVE SYSTEM TO FIRE BLIGHT (ERWINIA AMYLOVORA) ATTACK

The fireblight of rosaceous species is a very important disease for fruit growing in general and for the pome fruits species cultivation as well, especially under the conditions of expansion of superintensive training systems and in the context of current climate changes.During 2016-2018, the reaction of some performant apple cultivars grown under superintensive system to the attack of fireblight (Erwinia amylovora Burill Winslow) was assessed and was dependent on the variety/rootstock combination, trees age, and environmental conditions, presence of the pathogen and its aggressiveness and management of some technological links.Our study revealed that the most sensitive cultivar/rootstock combinations were 'Dalinco/Pajam1', 'Topaz/M9', 'Topaz/T337', 'Dalinbel/T337' and 'Dalinette/M9' (11 years old).At the other end, the most resilient combinations were 'Golden Orange/T337', 'Ariane/M9', 'Iniţial/M9', 'Rebra/M9', i 'Rustic/M9' (11 years old) and 'Mitchgala/M9' and 'Golden Delicious/M8' (3 years old).In the future, to overcome their sensitivity to fireblight, the varieties 'Dalinco', 'Dalinbel', 'Dalinette' and 'Topaz' might be grafted on M7 or other tolerant low vigor rootstocks.