SEEDLING DEVELOPMENT OF SUGAR MAPLE AND BLACK MAPLE IRRIGATED AT VARIOUS FREQUENCIES

Growth, dry-matter partitioning, and specific mass of lamina of black maple (Acer nigrum Michx.f.) and sugar maple (A. saccharum Marsh.) irr igated at 10-, 26-, and 42-day intervals were compared. Total dry mass , stem length, and surface area of lamina were greater for sugar maple than for black maple for plants irrigated every 10 days. Reducing irr igation frequency curtailed growth of both species, but the reduction was greater for sugar maple than for black maple. The shoot : root rat io was lower for black maple than for sugar maple and was reduced by d rought in both species, particularly among plants irrigated every 26 d ays. Specific mass of lamina increased as plants aged, was greater for black maple than for sugar maple, and decreased in response to irriga tion at 42 day intervals. The slower growth, lower shoot : root ratio, and greater specific mass of lamina of black maple indicate this spec ies has a greater capacity to withstand drought than sugar maple.