Microbiological Processes Associated with the Use of Chitin for Biological Control

Abstract

AbstractIn an investigation of the mechanism of action of chitin in the biological control of Fusarium solani f. phaseoli in soil, statistically significant control of a root rot caused by the fungus was noted when the aminopolysaccharide was added to soil up to 2 weeks prior to planting. No significant suppression by the microflora responding to the amendment was observed in longer periods of preincubation. Saprophytic soil fungi were also inhibited during the first 2 weeks after chitin incorporation. Actinomycetes, chitinase‐producing microorganisms, and chitinase activity were markedly stimulated during that period of time, but the population of bacteria was not altered appreciably. It is suggested that mycolytic activity and toxin production may be implicated in the selective influence of chitin in suppressing certain soil fungi. Acetate effectively controlled disease, but it appears that the mechanisms of action of chitin and acetate are distinct.