Integration of soil solarization with host resistance in the control of dieback and collar and root rot diseases of periwinkle

Abstract

Resistant and susceptible varieties of periwinkle (Catharanthus roseus) were grown in solarized and non-solarized plots during 1986 and 1987 to study the control of dieback and collar and root rot diseases caused by Pythium aphanidennatum through soil solarization and host resistance. Soil solarization significantly reduced plant mortality due to these diseases in the susceptible variety, WH 12, during both years and in the resistant variety, WH 40, only during 1987. Further, during 1987, plant mortality in solarized plots was observed 45 days later than in non-solarized plots. Soil solarization and host resistance together reduced plant mortality by 72-91 %. Soil solarization significantly increased leaf and root yields of both resistant and susceptible varieties by 26-52%.