EPIDEMIOLOGICAL SURVEY OF EUROPEAN STONE FRUIT YELLOWS PHYTOPLASMA IN TWO ORCHARDS IN WESTERN SWITZERLAND

Valais is the main apricot producing region in western Switzerland.
Apricot chlorotic leaf roll (ACLR) is re-emerging in this region, especially in commercial orchards renewed with non traditional varieties.
The presence of European stone fruit yellows (ESFY) phytoplasma was clearly demonstrated to occur on a great number of diseased trees.
However, the potential threat of ACLR in Valais was unknown, so, an epidemiological survey was conducted in two orchards.
Apricot trees have been monitored by PCR and symptom observation.
Results of the 4 years survey on a limited number of trees in a naturally contaminated orchard, revealed an important annual progression of infected trees.
In a second isolated orchard, situated in a non apricot producing area, trees were experimentally infected in summer by graft inoculation.
In this case, ESFY could be detected by PCR on some varieties as early as in the following season.
Foliar and fruit symptoms were observed during the first or second growing season, respectively.

XIX International Symposium on Virus and Virus-like Diseases of Temperate Fruit Crops – Fruit Tree Diseases

M.E. Ramel, P. Gugerli

Phytoplasma, Apricot chlorotic leaf roll disease, European stone fruit yellows, PCR

https://doi.org/10.17660/ActaHortic.2004.657.74