Effects of Dipel 176, a Bacillus thuringiensis subsp. kurstaki (Btk.) formulation, on the soil microflora and the fate of Btk in an acid forest soil: a laboratory study
Authors: Visser, S., Addison, J.A., Holmes, S.B.
Journal, Volume, Year: Canadian Journal of Forest Research, volume 24:462-471, 1994
Simple microcosms, containing samples of litter (L) or fermentation-humus (FH) from a coniferous forest, were used to determine the persistence of Btk and effects of Dipel�176 (Btk) on microbially mediated carbon and nitrogen mineralization processes over an 8 week period. Respiration monitoring, basal respiration, microbial biomass, qCO2, NH4-N, NO3-N, and cellulose decomposition did not respond significantly to Dipel�176 at recommended field rates. Effects on C and N mineralization processes were found at 1,000X recommended application rate. L and FH did not reduce viability of Btk over the 8-week study.
Although some effects were noted at the 1,000X rate, it is unlikely to occur under field conditions. This study does not allow distinction between effects from Btk propagules and crystals and the effects of the carrier constituents.