Effect of virazole (ribavirin) on tomato spotted wilt virus in two systemic hosts, tomato and tobacco.

Virazole (1, beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide = Ribavirin), a synthetic nucleoside analogue, has been successfully used against tomato spotted wilt virus (TSWV) in tomato and tobacco plants. In tomato, the most efficient concentration to control TSWW was 500 mg/l while in tobacco, concentrations of 100 mg/l were sufficient to control systemic infection. When the plants did not show a systemic reaction virus could not be recovered from inoculated and treated tomato and tobacco plants by means of the local lesion assay. The results point out the response of a new plant virus to Virazole and indicate a possibility of controlling TSWW systemic infection.