FIRST OCCURRENCE OF APRICOT BLAST DISEASE CAUSED BY PSЕUDOMONAS SYRINGAE IN THE NORTH-EASTERN PART OF BULGARIA

The apricot trees grown in the North-Eastern part of Bulgaria are frequently affected by decline with typical bacterial canker symptoms.
During the spring and summer of 2004, 2005 and 2006 this occurrence was observed on more than 85% of apricot trees (Prunus armeniaca L.) grown in commercial orchards and home gardens in the provinces of Rouse, Silistra, Dobrich, and Shoumen in Bulgaria.
Initial characteristic symptoms were mainly on young apricot trees (1-4 year-old) as trunk and bark small or larger cankers with sap flow and dark-amber gumming at bud unions, crotches, pruning wounds or at the base of affected spurs.
Subsequent development of the disease was expressed as blossom blast, dried leaves attached to trees, twig dieback, bark necrosis and large trunk cankers.
A total number of 27 bacterial strains were able to induce a hypersensitive reaction on tobacco leaves (Nicotiana tabacum) according Klement’s method (1963). The pathogenеcity of the Pseudomonas strains was confirmed by spray-inoculating on one-year-old apricot trunks and twigs and expressed as area of tissue injured by the infection.

I Balkan Symposium on Fruit Growing

L. Ivanova

Pseudomonas syringae, Prunus armeniaca, canker, decline

https://doi.org/10.17660/ActaHortic.2009.825.20