Survey on virus diseases of almond in Lebanon
In Lebanon, a survey carried out in 1995 on virus diseases of cultivated almond (Prunus dulcis) had showed the presence of Prunus necrotic ringspot ilarvirus and Prune dwarf ilarvirus. Another survey was recently done on a larger geographical area and included both cultivated and wild almonds (P. orientalis, P. korschinskii) from all almond-growing regions of Lebanon. In most orchards surveyed, no characteristic symptoms of viral infections were seen. Plant samples (599) were collected and tested by ELISA for the presence of the most important stone fruit viruses. As a result, 10.3% of the samples showed positive results to one or more viruses. The following viruses were detected: Prunus necrotic ringspot ilarvirus (average incidence 3.3%), Apple chlorotic leaf spot trichovirus (2.7%), Prunus dwarf ilarvirus (2.5%) and Apple mosaic ilarvirus (1.8% - EPPO A2 quarantine pest, on Rubus). This survey showed that Prunus necrotic ringspot ilarvirus and Prune dwarf ilarvirus infections on cultivated almond are present throughout Lebanon but with a low incidence. Neither viruses was detected in wild almonds. The survey also revealed the occurrence of Apple chlorotic leaf spot trichovirus on almond (both cultivated and wild), and Apple mosaic ilarvirus is reported for the first time in Lebanon. Tomato ringspot nepovirus and Plum pox potyvirus were not detected during this survey.
Sources
Kanaan-Atallah, Z.H.; Abou-Jawdah, Y.; Saad, A. (2000) Virus diseases infecting almond germplasm in Lebanon.
Phytopathologia Mediterranea, 39(3), 417-422.