Articles
CHERRY RASP LEAF ETIOLOGY IN CAMPANIA
Complaints from growers about dying or declining have been frequent the last ten years.
A preliminar investigation explained that weakness and decline in Caserta and Benevento provinces are mostly related to Armillaria Root Rot, Crown Gall and Goat Moth (Cossus cossus L.).
A survey of the symptoms in the other two provinces showed that the decline is always associated with rasp leaf.
In 1982 Ragozzino et al. reported the isolation of Prune Dwarf Virus (PDV) and Strawberry Latent Ringspot Virus (SLRV) from declining Cherry trees in Avellino province.
Further investigations have confirmed the presence of PDV and SLRV in rasp leaf affected trees and of SLRV in some apparently healthy ones.
Nematodes (Longidorus sp., Xiphinema pacthaicum, X. italiae, Macropostonia xenoplax) have been recovered from the soil around infected trees.
No one of these nematodes is reported to be vector of SLRV and the transplanting of bait plants in infested soil didn’t lead to the transmission of SLRV or other virus.
It is apparent that SLRV alone would be latent in our Cherry varieties and that an increase in rasp leaf disease could be caused by spread of PDV into trees with such latent infection.
In 1990 an investigation was carried out in the etiology of rasp leaf in Naples province.
An ILAR virus, identified as PDV, was isolated on herbaceous hosts from infected Cherry trees, but not from healthy ones.
The inoculation of Prunus domestica with bark chips from naturally rasp affected cherries induced leaf deformation typical of PDV. Examination of soil specimens revealed several nematodes including Longidorus spp., Xiphinema pacthaicum, X. italiae and X. diversicaudatum.