Apricot Chlorotic Leaf Roll

Authors

  • G. MORVAN

    1. Station de Pathologie Végétale (INRA), Avignon-Montfavet (France)
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    • 1)

      The author wishes to thank his colleagues:

      — J. Duquesne, Laboratoire d'Arboriculture, ENSAM, Montpellier (France).

      — G. Llager, Centro regional de Levante, INIA, Burjasot-Valencia (Spain).

      — F. Pelet, Station Fédérale de Recherches Agronomiques de Changins, Nyon (Switzerland) for their remarks and suggestions which allowed him to give a more accurate description of the disease as it appears in Western Europe.

      He is very grateful to W.J. Moller, Agricultural Extension, University of California, Davis, who kindly corrected and improved the English translation.


Abstract

Apricot chlorotic leaf roll is a graft-transmissible disease, apparently a mycoplasm infection, which affects Japanese plum and sometimes peach. It is particularly important in Mediterranean areas.

First symptoms are a rolling and a yellowing of the leaves, often localized on some twigs. Later, various disorders, often localized on a part of the tree, are observed: proliferation of branched and slender shoots, growth of buds in autumn and winter. Leaf buds break before flower buds.

This growth in winter induces sensitivity to frost. Phloem tissues of affected branches are more or less damaged, taking on a brown discolouration. Some branches are destroyed, while on others, new shoots may develop. The presence of weak shoots with small leaves among normal shoots and irregularly distributed dried twigs on the branches is a characteristic aspect of the disease.

Symptom expression and evolution of the disease vary much according to environmental conditions, age and rootstocks.

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