Antiviral Properties of Garlic Cloves Juice Compared with Onion Bulbs Juice Against Potato Virus Y (PVY)

Potato y disease caused by potato virus y (PVY) is widespread wherever potato is grown. PVY affects plants and yields. The effectiveness of extracts from garlic cloves (GE) and onion stems (OE) against potato virus y (PVY) in vitro and in vivo has been evaluated. GE and OE reduced the in vitro and in vivo infectivity of PVY to a certain extent, expressed as the number of local lesions induced by PVY on Chenopodium amaranticolor plant as a local lesion host. The effect of these extracts and their dilutions (from 10 to 10) was the highest in the crude extract and decreased gradually by increasing the extracts dilutions from 10 to 10. PVY inhibition percentages induced by GE and OE varied according to the time of treatment (1, 2, 3 and 4 days). High percentages of inhibition were recorded for in vitro treatment. The highest effect of GE against PVY infectivity was in the crude extract and after 4 days (percentage of inhibition was 63.63 %). While, the highest percentage of inhibition of OE against PVY infectivity was 51.51 % in the crude extract and after 4 days. PVY inhibition of pre-inoculation treatment was higher than that of post-inoculation treatment. In pre-inoculation treatment, the highest effect of GE against PVY infectivity was in the crude extract and after 4 days (percentage of inhibition was 38.89 %). While, the highest percentage of inhibition of OE against PVY infectivity was 33.33 % in the crude extract and after 4 days. In post-inoculation treatment, the highest effect of GE against PVY infectivity was in the crude extract and after 4 days (percentage of inhibition was 33.33 %). While, the highest percentage of inhibition of OE against PVY infectivity was 30.56 % in the crude extract and after 4 days. So, GE was more effective in reducing the local lesions produced by PVY on Chenopodium amaranticolor than OE. [Journal of American Science 2010;6(8):302-310]. (ISSN: 1545-1003).