Authors: K Elena
Publish Date: 2006/05/12
Volume: 115, Issue: 2, Pages: 259-262
Abstract
During the last three years a new disease was observed in northwestern Greece on Minneola trees hybrid of mandarin and grapefruit On May small brown necrotic leaf spots surrounded by yellow halo areas of various sizes appeared and covered a major portion of the leaves with extension of necrosis into the veins On young fruits small slightly depressed black spots were the first symptoms which later became 2–7 mm in diameter Brown spots were observed on the leaves and fruits in several orchards in the same area causing leaves and fruits to drop In some orchards over 50 of the fruits were affected From the fruit and leaf spots the typical smallspore species Alternaria alternata was isolated Pathogenicity tests were performed by artificially inoculating fruits of Minneola common mandarin and Clementine The symptoms of the disease were reproduced only on fruits of Minneola hybrids by the specific strain of the fungus Alternaria alternata pv citri Different citrus susceptibility tests indicated that mandarins Minneola Nova and Page were very susceptible to tested isolates while Clementine SRA and Poros Clementine were not All lemons and lime Seedless were not susceptible Grapefruit New Hall was not susceptible while the Star Ruby was Orange Lane Late Navel Late Oval Poros Olinda Navel Athos were not susceptible and only Moro showed reaction being slightly susceptible only to one isolate
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