Involvement of Fluorescent Pseudomonads and Other Microorganisms in Increased Growth Response of Plants in Solarized Soils

Enhancement of plant growth in the absence of known pathogens was studied in solarized soils and, to a limited extent, in methyl bromide- and in metham-sodium-treated soils. Increased growth response, expressed by increased dry weight of tomato plants in treated over untreated soils in the greenhouse, was evident in most of the 24 tested soils from various locations in Israel. Increased growth also was evident in field experiments and in an artificially heated soil. Regression analyses showed a significant, inverse relationship between soil pH and increased growth and between soil pH and population densities of fluorescent pseudomonads in the rhizosphere (...)