Mycorrhizal status, soil and foliar nutrient status, and production histories were determined for Japanese black pine (Pinus thunbergiana Franco.) and dwarf Mugo pine (Pinus mugo Turra ‘mugo’) in 4 Long Island, New York nurseries. All pines sampled were mycorrhizal. No significant effect of age on percentage mycorrhizal roots was observed between 2-,3- and 5-year-old Japanese black pine. The extent of mycorrhizal formation with Mugo pine could not be correlated with differences in soil or foliar nutrient status among 3 field nurseries. However, field grown Mugo pine had approximately 20% more mycorrhizal roots (70%) than container grown plants (50%). A controlled greenhouse study of Mugo pine inoculated with the ectomycorrhizal fungus Pisolithus tinctorius (Pers. Coker and Couch) showed decreased mycorrhizal levels with increased N, suggesting that differences in mycorrhizal intensity between field and container grown nursery stock may have been related to differences in fertility.
2Former graduate research assistant, presently Assistant Professor, PlantScience Department, Utah State University, Logan, Utah.