CUTTING CYCLE AND SPACING EFFECTS ON BIOMASS PRODUCTION BY A WILLOW CLONE IN NEW-YORK

An experiment was established in central New York State in 1990 to det ermine cutting cycle and spacing effects on willow biomass production. Cutting cycles were annual, biennial and triennial, and spacings were 0.3 x 0.3, 0.3 x 0.9, and 0.6 x 1.1 m; biomass production and surviva l by willow clone SV1 (Salix dasyclados) were measured. Beginning in t he second growing season, trees were fertilized with N, P and K, and i rrigated. Willow clone SV1 harvested triennially with 0.3 x 0.9 m spac ing yielded 71.3 odt ha(-1), an average annual production of 23.8 odt ha(-1) year(-1). Spacing of 0.3 x 0.9 m yielded the most biomass, but spacing differences were not significant for biomass production. Trien nial harvesting was significantly more productive than cumulative prod uction after 3 years with annual harvesting (64.5 versus 39.2 odt ha(- 1)). Cumulative production from two biennial harvests was significantl y larger than cumulative production from four annual harvests (64.3 ve rsus 50.1 odt ha(-1)). Tree survival was similar among cutting cycles after five growing seasons, averaging 75%. Statistically significant d ifferences in survival were detected among spacings, averaging 88, 80 and 57% at 0.60 by 1.1, 0.3 x 0.9 and 0.3 x 0.3 m spacings. respective ly during 1994. Copyright (C) 1997 Elsevier Science Ltd.