Effects of Hebeloma arenosa on growth and survival of container-grown red pine seedlings (Pinus resinosa)

Abstract

The ability of the ectomycorrhizal fungus Hebelomaarenosa Burdsall, MacFall & Albers to enhance growth and survival of container-grown red pine seedlings (Pinusresinosa Ait.) was investigated. Shoot height of H. arenosa inoculated seedlings was 28% greater than noninoculated seedlings when grown without fertilizer applications. Eight-week-old seedlings transplanted into a Ball mix (a mixture of peat, bark, and perlite) containing up to a 1:64 dilution of fungal inoculum had significantly greater root dry weights and root/shoot ratios than noninoculated seedlings when grown for an additional 14 weeks. Under experimental greenhouse conditions, root and shoot dry weights of container-grown red pine seedlings that had been directly seeded into Ball mix containing up to a 1:256 dilution of fungal inoculum were significantly greater than weights measured for noninoculated seedlings. Root and shoot dry weights of container-grown seedlings seeded directly into a 1:5 dilution of H. arenosa inoculum and Ball mix and then grown under commercial production conditions were greater than comparable weights of noninoculated seedlings. Hebelomaarenosa inoculation significantly increased seedling survival following outplanting, but did not increase seedling growth. Hebelomaarenosa did not colonize roots growing from the root plug into the surrounding soil.