Effect of volatile inhibitors from natural and amended soils on germination of sclerotia of <i>Macrophomina phaseolina</i>

Studies on volatile soil fungistasis showed that sclerotia of Macrophomina phaseolina are not sensitive to volatiles liberated by natural soils with varying pH values. Soil amended with alfalfa hay (1%, w/w) liberated volatiles fungistatic to sclerotia only when the assay was performed 2 weeks or less after amendment. Chitin-amended soils liberated fungistatic volatiles from 1 to 3 weeks after amendment. Indirect evidence indicated that ammonia may be the active volatile in amended soil. It was concluded that fungistatic volatiles may not play an important role in the survival of sclerotia in nature. </jats:p