UN DEPERISSEMENT DU POIRIER OBSERVE EN FRANCE SIMILAIRE AU “PEAR DECLINE” OU “MORIA”

Two types of decline were recorded on the pear variety ‘Beurré Hardy’ budded on pear seedlings (Pyrus communis).

The slow decline begins with an early reddening on the lower side of the lamina and then on the upper side with deformations of the leaves (among 3,440 trees recorded 20% show this symptom). The next year a small number of trees seemed to be cured with normal growth (16%). The other trees made poor growth, had a reduced leaf area and many clusters of leaves.

In August, some trees (2%) with good growth develop a quicke decline with a sudden wilting.

Trials with 11 indicators have demonstrated the transmission of this symptom.
A slow decline has been recorded one year after inoculation on ‘Doyenné du Comice’, ‘Beurré Hardy’, ‘Beurré Bosc’, Pyrus A. 20, Pyrus Variolosa and Pyronia Veitchii.

No symptoms at all have been observed on Quince C. 7/1, and Malus ‘Lord Lambourne’ and ‘Virginia Crab’ three years after inoculation.

The etiology of this disease looks like the pear decline or Moria.

IX International Symposium on Fruit Tree Virus Diseases

J. Lemoine

https://doi.org/10.17660/ActaHortic.1975.44.21