Soil-borne propagule populations of isolates of Phytophthora cryptogea and P. parasitica in relation to inhibition of growth of tobacco plants

Abstract
The relationship between populations of soil-borne propagules and inhibition of growth of tobacco plants by isolates of Phytophthora cryptogea and P. parasitica incapable of killing tobacco plants was investigated. Although plants usually were severely stunted, they had no effect on populations of the two fungi. This relationship supports the concept that growth inhibition of tobacco plants by these fungi is due to nonparasitic pathogenesis.