Incidence of Nonpersistently Transmitted Viruses in Pepper Sprayed with Whitewash, Oil, and Insecticide, Alone or Combined. S. Marco, Department of Virology, ARO, The Volcani Center, Bet Dagan 50250, Israel. . Plant Dis. 77:1119-1122. Accepted for publication 13 May 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-1119.

Several methods of protecting pepper (Capsicum annuum) against aphid-borne virus diseases were evaluated in field experiments for 6 yr. Results of weekly sprays of the insecticide pirimicarb (Pirimor) or bifenthrin (Talstar) at 0.1% or of a mixture of pirimicarb at 0.1% and whitewash (Yalbin) at 10% did not differ from those of unsprayed controls. Applications of mineral oil (Virol) at 1% or of whitewash (Yalbin or Loven) at 10% reduced the incidence of virus infection by about 40%. The best control was achieved with Yalbin combined with bifenthrin or mineral oil, which reduced virus infection by about 60%. Whitewash treatments caused slight damage to pepper seedlings at the first-true-leaf stage but did not damage older plants. In three of four experiments, whitewash-treated plots had significantly higher yields than control plots. In the fourth, however, the yields in treated plots were lower, and the possible direct effect of whitewash treatment on the pepper plant is discussed. Yields with whitewash plus bifenthrin did not differ from yields with whitewash alone. Treatments with whitewash plus pirimicarb or whitewash plus mineral oil were more harmful, and the latter decreased yields significantly. Potato virus Y, the most prevalent virus, was found in 86% of infected plants, cucumber mosaic virus in 23%, and alfalfa mosaic virus in only one sample. Several plants had mixed infections.