Articles
FIRE BLIGHT OF POMACEOUS FRUIT TREES IN MACEDONIA – CHARACTERISTICS OF THE PATHOGEN ERWINIA AMYLOVORA
The pathogen, recently a quarantine bacterium parasite for our country, has already been causing considerable damages with a tendency for further spread.
The purpose of the present study was: (1) to show economic importance and dissemination of E. amylovora in Macedonia, (2) to test pathogenicity, (3) to verify properties by morphological, biochemical, physiological and serological tests and (4) to compare the strains isolated in Macedonia with an authentic strain from France.
The disease registered in 15 communities of the total surface in Macedonia is estimated at about 500 ha under pears and about 60 ha under quince trees.
A great part of the area is already cleared.
The expenses for cleaning and planting new seedlings could be estimated at about $7,000,000.
From 83 isolates of E. amylovora, 47 from pear and 36 from quince trees, isolated during 1991 and 1992, eight isolates and two reisolates were studied in detail.
Our investigation showed that strains from Macedonia are identical to E. amylovora, the causal agent of “fire blight” disease of the pomaceous trees and they constitute a homogeneous population, regardless of their host plant, place (locality) or date of isolation and do not constitute a special strain of the pathogen.