P-144 - Susceptibility and resistance of pepper species and cultivars to Colletotrichum scovillei causing green fruit anthracnose in eastern North America

Since 2019, green fruit anthracnose caused by the fungus Colletotrichum scovillei has resurged on various types of sweet and hot peppers (Capsicum spp.) grown in eastern North America on conventional and organic farms. The objective of this study was to determine the reaction to C. scovillei of 16 pepper cultivars representing 11 horticultural types from four Capsicum species. In the field, test plants were naturally inoculated by promoting spread of conidia into plots from inoculated fruit on plants located between plots. In summer 2022 and 2023, fruit were harvested five times and sorted into diseased and healthy classes. Disease incidence on fruit at the last two harvests, averaged across years, ranged from 0.3 to 99.8%. All four Capsicum spp. differed from each other (P ≤ 0.01) and were ranked from susceptible to resistant as C. annuum, C. baccatum, C. chinense, and C. frutescens, respectively. All seven C. annuum cultivars had >70% fruit rot incidence, while both C. frutescens cultivars had < 1% incidence. Cultivars with red fruit at maturity had lower fruit rot incidence than cultivars with green, yellow, or orange fruit (P = 0.0004). Fruit rot incidence was not correlated with mean Scoville heat units. C. frutescens may be useful as a source of resistance to develop new pepper cultivars that would help growers manage green fruit anthracnose.