Effect of Glomus Spp. on the Growth of Eastern Cottonwood Cuttings

The rapid juvenile growth of eastern cottonwood (Populus deltoides Bartr. ex Marsh.) makes it a desirable hardwood species for revegetation of disturbed sites. In addition, revegetation may be facilitated by improved root growth in response to endomycorrhizal colonization. An experiment was conducted to identify the effect of inoculation with a mix of three Glomus spp. isolates on the root growth rate of eastern cottonwood cngs. Results indicated that endomycorrhizal colonization of eastern cottonwood cuttings was successful using commercial endomycorrhizal spore inoculum. However, endomycorrhizal inoculation appeared to have a negative effect on growth during greenhouse production. Factors contributing to this response are discussed. Reduced root growth rate in response to endomycorrhizal inoculation, but lack of either shoot or root dry weight response , suggests that endomycorrhizal inoculation may have affected root system morphology.