Growth, Ectomycorrhizal Development, and Root Soluble Carbohydrates of Black Oak Seedlings Fertilized by Two Methods

Abstract

Abstract Pisolithus tinctorius inoculated and noninoculated Quercus velutina seedlings were grown in book planters and fertilized by two methods. Fertilizer mixtures composed of nitrogen-phosphorus-potassium (NPK) or nitrogen-magnesium (NMg) were applied as a mist to the foliage of seedlings or as a solution to their rooting medium. Seedling growth, ectomycorrhizal development, and soluble carbohydrate content of short roots were significantly affected by type of fertilizer and method of application. Fructose content of short roots of seedlings receiving foliar NPK was significantly greater than in seedlings which had NPK and NMg added to the rooting medium. Significantly more ectomycorrhizae were formed on seedlings receiving foliar applied NPK and NMg than those receiving the same fertilizers as a solution to their rooting medium. Fructose content of short roots was significantly correlated with ectomycorrhizal development and accounted for 89 percent of the variation in the susceptibility of short roots to infection by Pisolithus . These results suggest that it may be possible to avoid high concentrations of soil nutrients and to stimulate ectomycorrhizal development on Quercus seedlings by applying fertilizers directly to the foliage as a fine spray mist. Forest Sci. 27:617-624.