Cross protection of glasshouse tomatoes against tobacco mosaic virus

Abstract

Abstract A mild strain of tobacco mosaic virus (TMV) was used to cross protect the TMV-susceptible tomato cultivars ‘Potentate’ and ‘V548’ in a commercial glasshouse trial. Plants infected with the mild strain (MII-16) showed increased fruit set and approximately 25% greater yields than those infected with a severe strain of TMV. The number of flowers formed was not affected by infection with either strain. The mild strain did not affect crop growth and infected plants remained symptomless throughout the trial. Application of the mild strain by hand inoculation resulted in a greater proportion of infected plants than inoculation by the airbrush method. Efficiency of the airbrush method was greatly influenced by the stage of plant development at the time of inoculation. Plants became protected from severe strain TMV infection 8 days after the mild strain inoculation.