Longer black willow cuttings result in better initial height and diameter growth in biomass plantationsThis article is part of a larger document. View the larger document here.
Black willow (Salix nigra Marsh.) has the potential to be a viable plantation species for biomass production on heavy clay soils throughout the southern United States. The most favorable planting stock for woody biomass plantations is dormant unrooted cuttings, because they are easy to plant and use of clonal material allows for advancing genetic improvement. The purpose of this study was to determine the optimal cutting size and planting depth for maximum survival and growth of unrooted black willow cuttings. A test using three cutting lengths (9, 15, 21 inches), four cutting diameters (⅜, ½, ¾, 1 inches), and three planting depths that left 2, 5, and 8 inches of exposed unrooted cuttings was established in 2009, and survival and growth were measured for two growing seasons. Second-year survival exceeded 99 percent across all treatment combinations and was not influenced by any of the experimental factors. Total height differed among cutting length and cutting diameter. The 21 inch cuttings produced stems with the greatest heights and diameters two growing seasons after planting, but the largest cutting diameters did not produce the same effect. Our results indicate that cutting length had a stronger influence than either cutting diameter or planting depth on black willow height and diameter growth during the first two growing seasons after planting.