Abstract

The purpose of this study was to evaluate the effects of NaCl and freezing temperatures on dormant lateral buds of Acer platanoides L. (Norway maple), Tilia cordata Mill. (littleleaf linden), and Viburnum lantana L. (wayfaringtree viburnum). The role of bud morphology was also examined. Buds were exposed to three NaCl concentrations [0, 2000, or 16,000 mg/liter (0, 2000, 16,000 ppm)] and eleven freezing temperatures [4, −4, −8, −12, −16, −20, −24, −28, −32, −36, and −40C (39, 25, 18, 10, 3, −4, −11, −18, −26, −33, −40F)] in November 2001 and January and March 2002. Electrolyte leakage and visual ratings of outer and inner bud tissue browning were used to assess injury. Bud injury generally increased as NaCl concentrations increased and temperatures decreased. Buds exposed to NaCl and freezing temperatures had greater electrolyte leakage than buds exposed to freezing temperatures alone. Norway maple buds had the highest electrolyte leakage, followed by wayfaringtree viburnum, and littleleaf linden in response to freezing temperatures and NaCl. The naked buds of viburnum had significantly more inner tissue browning than the scaled buds of maple and linden in response to freezing temperatures and NaCl in January 2002. Wayfaringtree viburnum exhibited increased tissue injury in response to NaCl and low temperature treatments in March 2002.