Effects of vesicular-arbuscular mycorrhizae and seed source on nursery-grown black walnut seedlings

A nursery study was established in Missouri to evaluate the effects of endomycorrhizal inoculation and seed source on the growth of black walnut seedlings. Inoculation, in general, resulted in seedlings with significantly larger sturdiness quotients. Glomus intraradicies was found to produce larger seedlings than Glomus etunicatus, but only differences in height were significant. Seed source affected the quality of seedlings and produced highly significant differences in height and number of first order lateral roots. Inoculation by seed source interactions was significant only for height growth. However, the study clearly demonstrates variation in walnut growth responses with changes in endomycorrhizal symbiont and seed source. Preliminary results indicate that improvement in black walnut seedling quality can occur as a result of inoculating some walnut genotypes with specific endomycorrhizal organisms.