Relationship Between Inoculum Level ofPhytophthora capsiciand Mortality of Pepper

Relationships between the levels of oospore and zoospore inoculum of Phytophthora capsici and mortality of pepper (Capsicum annuum) were investigated. Oospore progeny from 20 pairings of pathogenic isolates of P. capsici varied in pathogenicity to pepper at an initial inoculum density of 25 oospore per gram of soil. Only oospore inoculum from specific pairings caused disease in growth room experiments. The highest mortality (30-75%) resulted from oospore inoculum produced from pairings involving certain isolates of A2 compatibility type. Oospore inoculum from other pairings caused little or no disease (0-5%) (...)