Inoculation of Nursery Seedbeds with Pisolithus Tinctorius Spores Mixed with Hydromulch Increases Ectomycorrhizae and Growth of Loblolly Pines

Abstract Different methods of introducing basidiospores (4/5 oz. spores/100 linear ft. of nursery bed) of Pisolithus tinctorius into fumigated soil at Weyerhaeuser's nursery in Oklahoma were tested to determine their effectiveness in forming ectomycorrhizae on loblolly pine seedlings. Two of five methods proved significantly effective. Nearly three-fourths of seedlings treated with spores mixed in hydromulch and applied after sowing formed Pisolithus ectomycorrhizae. The result was 25 percent larger seedlings and 15 percent fewer culls. In plots where spores were dusted onto the soil at sowing, one-third of the seedlings formed Pisolithus ectomycorrhizae, resulting in 12 percent larger seedlings and 13 percent fewer culls.