EFFECTS OF TRICHODERMA SPP AND AMMONIUM SULFAMATE ON ESTABLISHMENT OFARMILLARIA-LUTEOBUBALINA ON STUMPS OF EUCALYPTUS-DIVERSICOLOR

Stumps of karri (Eucalyptus diversicolor) were simultaneously inoculat ed with the pathogen Armillaria luteobubalina and five combined isolat es of Trichoderma spp, to examine their potential for biological contr ol. Trichoderma inoculum was placed in holes drilled into the stumps o r in slashes cut in the bark and sapwood about 5 cm above the ground l ine, either as (a) conidia suspended in an agar matrix, or (b) mycelia and conidia encased in calcium alginate beads and suspended in an aga r matrix. Half the stumps were poisoned with application of ammonium s ulphamate (AMS) to the freshly cut stump top. The stumps were harveste d 2 yr after inoculations. Observations and isolations made from disse cted root and stem sections indicated that (a) AMS treatment significa ntly increased colonization of stump roots by A. luteobubalina, and (b ) Trichoderma spore inoculum, v. bead inoculum, placed in drill holes in the stumps resulted in a significant reduction in root colonization by A. luteobubalina. Spore inoculum may have adversely affected fruit ing of A. luteobubalina on stumps as well, since none of the 20 stumps on which A. luteobubalina fruited was inoculated with spores.