Expression of Age-Related Resistance in Pepper Plants Infected with Phytophthora capsici. Young Jin Kim, Graduate Student, Department of Agricultural Biology, Korea University, Seoul, Korea. Byung Kook Hwang, and Kuen Woo Park. Professor, Department of Agricultural Biology, and Professor, Department of Horticulture, Korea University, Seoul, Korea. Plant Dis. 73:745-747. Accepted for publication 13 February 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0745.

Eight pepper cultivars with different degrees of resistance to Phytophthora capsici were evaluated on the basis of a disease severity rating for age-related resistance under controlled environmental conditions. With increasing age of pepper plants, all cultivars tested became gradually resistant to Phytophthora blight. High inoculum concentrations of P. capsici resulted in symptoms on some resistant cultivars. The incubation periods of P. capsici in resistant pepper cultivars and old plants were longer than those in susceptible cultivars and young plants, respectively. The soil-drench method of inoculation was more reliable than the stem-inoculation method for evaluation of age-related resistance. Appropriate screening techniques for evaluation of age-related resistance are discussed.