First report of brittle leaf disease of date palm (maladie des feuilles cassantes) in Algeria
A lethal disease of date palm (Phoenix dactylifera) called brittle leaf disease (maladie des feuilles cassantes - EPPO Alert List) has been reported from Tunisia since the 1960s. Although no pathogen has yet been found associated with this disease, several aspects of its epidemiology do not suggest a purely abiotic cause (e.g. diseased plants are grouped into foci). A small dsRNA (not related to a known pathogen but probably related to the host) has been found associated with symptomatic trees and presents some diagnostic value in detecting the disease. In December 2003, symptoms of brittle leaf disease were observed in the Biskra region of Algeria (east of the country). In Lichana where the disease had in fact been observed since 1974, 29% of date palm trees were affected, while in some farms of Farfar up to 100% of the trees were affected. The disease was found in traditional oases as well as in new, industrial, date palm plantations in the Bouchagroun and Dra Elbetikh areas. All samples (P. dactylifera cv. ‘Deglet Nour’) from several areas (Vieux Zaatcha, Bouchagroun, Dra Elbetikh, Farfar) tested positive for the specific dsRNA. All affected leaflets tested were deficient in manganese, which is also a characteristic observed in the disease. This is the first documented report of brittle leaf disease of date palm in Algeria.
Sources
Saadi I, Namsi A, Ben Mahamoud O, Takrouni ML, Zouba A, Bové JM, Duran-Vila N (2006) First report of ‘Maladie des feuilles cassantes’ (brittle leaf disease) of date palm in Algeria.
New Disease Reports, Volume 13: February 2006 - July 2006