Relative water demand, RWD, of 2-year-old containerized seedlings of red maple (Acer rubrum L.), sugar maple (A. saccharum Marsh.), silver maple (A. saccharinum L.), Norway Maple (A. platanoides L.) and boxelder (A. negundo L.) was determined by comparing potential evapotranspiration rates and actual water consumption values with growth rates for each species. Based on differences in growth rate, each species was determined to be either fast growing (red maple, silver maple, boxelder) or slow growing (sugar maple, Norway maple). Fast growing species used the most water over the 3-month experimental period (June-August), and had the higher RWD. The actual irrigation demand for each species was closely correlated with monthly potential evapotranspiration rates as determined by the Thornthwaite equation.
Author notes
Research partially supported by an R.P. White Grant from the Horticultural Research Institute. Mention of a trademark or proprietory product does not constitute a guarantee or warranty of the product by the USDA, and does not imply its approval to the exclusion of other products that may be equally suitable.
2Research Plant Physiologist and Biological Technician, resp.