Comparative water relations of container-grown and bare-root ectomycorrhizal and nonmycorrhizal <i>Quercus velutina</i> seedlings

Abstract

A 2 × 2 factorial field experiment was conducted with black oak (Quercus velutina) to examine the effects of seedling production method (container-grown vs. bare-rooted) and inoculation with Pisolithus tinctorius on seedling water relations and soil–plant liquid flow resistance (R s - P ). Over the study period, bare-rooted and noninoculated seedlings exhibited midday values of leaf water potential (Ψ) which were lower than container-grown and Pisolithus-inoculated seedlings. During a mild drought in July similar trends were seen in predawn Ψ. Flow resistance between bulk soil and leaf was lower in container-grown and Pisolithus-inoculated plants than in bare-rooted and noninoculated plants; R s –p was particularly high in bare-rooted plants which were not inoculated with Pisolithus. The exact mechanism(s) accounting for the differences in R s –p of mycorrhizal vs. nonmycorrhizal plants could not be ascertained by the techniques employed. Low R s –p in container-grown plants was associated with greater total root system length.