Frequent Irrigation Increases Growth of Pot-in-Pot Sugar and Red Maple

Abstract

In Virginia, pot-in-pot production of shade trees is normally accomplished by growing bareroot whips in 56-L containers for two complete growing seasons (production cycles). This study monitored the growth of Acer saccharum L. `Green Mountain' (sugar maple), a species with moderate growth rate, and Acer rubrum L. `Franksred' (red maple), a species with a fast growth rate, under standard once-a-day irrigation regime (1X) and a cyclic three-times-a-day regime (3X). Equal daily volumes of water were applied under each regime. Height growth rate increased for sugar maples but decreased for red maples in production cycle two compared to production cycle one. Stem diameter growth rates remained steady for red maple, but increased slightly for sugar maple. A 3X irrigation regime increased stem diameter of red maples, but had no other effect on either species in year one. Height and stem diameter growth of both species were increased by the 3X treatment during production cycle two. This study indicates that the standard production period results in decreased growth in the second production cycle for red maple, but not for sugar maple. Growth rates can be enhanced with a 3X irrigation regime for both species in production cycle two. The 3X irrigation regime only increases the stem diameter growth of red maple in the first production cycle.