Use of Physical Barriers to Prevent Borer Infestations of Apple Burrknots

Abstract

Dogwood borer (DWB) infestation of burrknot tissue on apple dwarfing rootstocks is an increasing problem throughout the northeast. One insecticide, Lorsban, is currently the only efficient and effective chemical control available for DWB. Because of scrutiny of Lorsban under the EPA's FQPA policy, and the desire to increase options available to growers, a search for chemical alternatives to Lorsban has been ongoing. However, barriers to egg-laying by DWB may offer an effective, efficient, non-chemical control that may also serve as a deterrent to rodents. We tested four types of barriers including white latex paint, trunk wraps of Tyvek and veterinary gauze, and a sprayable, non-woven ethylene vinyl acetate (EVA). These were compared with the Lorsban standard and an untreated check. All barriers were effective in preventing DWB infestation, and remained intact throughout the growing season. However, paint and the EVA treatments held up better going into the winter. We also discuss economic considerations.