Growth comparisons between open-pollinated progeny of sugar maple grown under shade and in full sunlight

Progeny from two open-pollinated mother trees were grown for 1 year in a commercial tree nursery in Murphy, N.C. Shade cloths were applied to one half of the seed plots from each mother tree and the other half were exposed to full sunlight. Seedlings were fertilized throughout the growing season to increase growth performance for better discernment of progeny and shade effects. Seedlings in shaded plots were significantly taller and had larger root collar diameters (RCD) than unshaded seedlings. An interaction between progeny and shade effects on first-order lateral root number indicates that genetic or other unknown factors were affecting the seedlings' response to changes in light. Results indicate that the use of shade cloths in nurseries may improve seedling quality of 1-0 sugar maple in the southern portion of the species range.