Co-Authors:
Milgram, M.
Cohen, J.
Loebenstein, G., Dept. of Virology, ARO, Volcani Center, Bet Dagan 50250, Israel
Abstract:
Yield reductions of ca 50% or more were observed in field plots infected with both sweet potato feathery mottle virus (SPFMV) and sweet potato sunken vein virus (SPSVV) ('complex'), compared with plots planted with virus-free propagation stocks. No yield reductions were observed in a plot planted with SPFMV-infected cuttings. In plots infected with SPSVV alone, no significant effect on tuber yields was observed in one year, whereas in the second year there was a ca 30% reduction in yield compared with virus-free control plants. Reinfection in the field, in the absence of introduced infection sources, was observed only with SPSVV. However, natural spread resulted when SPFMV-infected source plants were introduced. This implies that aphid vectors were present during the growing season, but that SPFMV infection sources were absent from the area.