672 The Impact of East Coast Hurricanes on Apples

Abstract

Hurricanes or strong winds occasionally damage apple trees in the northeastern and mid-Atlantic regions of the U.S. Following the wind event, trees may be leaning or may be lying flat on the ground with extension root damage. Commercial growers generally pull trees upright while the ground is still moist and support the tree or just the trunk with various types of posts providing support to a height of about 60 to 200 cm above ground. In some cases the trees are pulled partially upright and propped up with boards or sand bags may be placed on the upwind side of the tree. Research data are not available for comparing various methods of treating the trees following wind damage, but field observations indicate that trees perform well if trees are pulled upright within 2 or 3 weeks after the wind event. Data from rootstock research plantings from several states indicate that tree anchorage is influenced by the combination of scion cultivar and root-stock. In Virginia in 1989, Hurricane Hugo brought wind gusts of about 95 km·h–1 when the ground was completely saturated by heavy rains. Trees in several plantings designed to evaluate rootstocks or cultivars were evaluated for the extent of leaning following the storm. The percentage of leaning trees on M.26 EMLA was <10% for `McIntosh' and `Golden Delicious' and 40% for `Delicious'. Susceptibility of trees on M.7A was also influenced by scion cultivar, with 0% for `Golden Delicious' and `Empire', 2% for `Redchief Delicious', and 88% for `TripleRed Delicious'.