Articles
THE APPEARANCE OF EUTYPA ARMENIACAE (HANSFORD) CARTER ON APRICOT AND GRAPE IN HUNGARY
Eutypa canker and die-back disease of grape caused serious economic losses on more than ten grape cultivars in all important grape growing areas.
For instance, in a 15-years old vineyard 15—20% of vinestocks was found to be killed and 68—85% of the surviving ones was infected.
It was surprising that the Eutypa fungus was only rarely present on apricot trees in close vicinity of seriously damaged vineyards, although the perfect (sexual) form of the fungus was frequently present on grapes.
The general opinion was that the same fungus species existed on both hosts.
The question arises, whether the same species infects apricot and grape or two different pathotypes exist in Hungary.
To solve this question some experiments were carried out; 1—3 year old opricot branches were inoculated with mycelium cultures of Eutypa armeniacae in June 1980, when according to Carter and Moller (1977) the trees were in the most susceptible stage.
Cultures of the fungus, used for inoculations, were isolated from grapevine and from apricot trees originating from Hungary and Australia.
The Australian strain was received from Dr.
Carter.
The inoculations were carried out on the surface of freshly prunned apricot branches by the method of Carter and Moller (1977). The cultures of Eutypa isolated from apricot and grapevine infected apricot trees and caused necrosis in the phloem and xylem tissue some months after the inoculation.
The first and second reisolations of the fungus from the necrotized tissues were carried out 4 and 12 months after the infection when the lenght of the cankers had reached 6—15 cms, respectively.
In this year in May the same experiment was repeated on grapevine, by apricot isolates for inoculations.
Visible symptom appeared one and a half month after the inoculation on the prunned surface of grape-stocks.
A 0.5—1 cm deep dark brown ring developed in the phloem