Articles
OCCURRANCE OF PLUM POX (SHARKA) VIRUS ON STONE FRUIT TREES IN EGYPT
The virus isolate was transmitted by grafting and mechanical inoculation to several apricot cultivars and to Mariana cultivars of plum.
The virus isolate was able to infect Pisum sativum, Solanum nigrum, Trigonella foenum graenum and Zinnia elegans. The aphids Nyzus persicae and Hyalopterus arundidis were able to transmit the virus in the non-persistent manner.
Diagnostic Symptoms of the disease were detected on apricot leaves, fruits and stones.
No symptoms were detected on peach or plum trees.
Indexing on GF 350 peach seedling and by ELISA revealed the presence of PPV in symtomless apricot, plum and peach trees.
The disease was prevalent on apricots in Fayum governorate so that in some orchards the level of infection was as high as 60%.
Contrarily, the rate of the disease dissemination was very low (1. 20%) in Kalubia governorate.
In Fayum area, the incidence of the virus on Hamawy cultivar was about 62%, followed by El-Amar (28%), while Balady had the lowest percentage of infection (5%). The distribution of the virus and the level of infection reflected a low natural spread of the virus by aphids on Balady cultivar.