Distribution of <i>Phytophthora cinnamomi</i>‐Supprcssive Soil in Nature

Abstract

Abstract Phytophthora cinnamomi ‐suppressivc soils were found to be widely distributed in nature. About 40 % of soil samples collected from locations with different vegetation, soil type or elevation throughout the island of Hawaii were suppressive to chlamydospore germination of Phytophthora cinnamomi . Soil samples collected from the same general areas varied greatly in degree of suppressive‐ness to P. cinnamomi , ranging from conducive to strongly suppressive. Among the 155 soil samples tested, those with pH close to 4 or 8 tend to be more suppressive to P. cinnamomi than those with pH close to 6.