Factors Predisposing Urban Trees to Sunscald    (View PDF)

Donald J. Roppolo Jr. and Robert W. Miller

Abstract: A variety of cultural practices such as deep planting and flush-cut pruning, as well as trunk and root injuries, are suspected of being causal factors in the development of sunscald on ornamental trees. Emerald Queen Norway maple (Acer platanoides 'Emerald Queen') and Greenspire littleleaf linden (Tilia cordata 'PNI 6025') were transplanted with these conditions and injuries, and with current guidelines for transplanting followed. These same species with sunscald injuries were dissected and examined microscopically to determine if a source of the injury could be determined. Trees in all treatment categories developed sunscald except those deep planted and receiving followup watering. Most sunscald injuries were associated with flatheaded borer (Buprestidae spp.) damage. Dissections revealed a number of causes of sunscald injuries, including borer damage, cankercausing fungi, and radial cracks in the xylem. Reducing the incidence of sunscald injury may be as simple as adequate watering the first growing season after transplanting.

Keywords: Buprestidae spp.; flush-cut pruning; Nectria canker; radial cracks; root injury; sunscald injury; transplanting; trunk injury; watering.

https://doi.org/10.48044/jauf.2001.026