Relative Susceptibility of New Apple Cultivars to Arthropod Pests

Abstract

As part of a regional NE-183 project (Multidisciplinary Evaluation of New Apple Cultivars), 23 apple (Malus ×domestica Borkh.) cultivars were evaluated for arthropod pest susceptibility. Incidence or injury data were collected from six foliage and eight fruit pests under field conditions over a four year period (2000–03). Cultivars were ranked based on susceptibility (least to most) to each pest, and rankings were summed for members of the foliage and fruit pest group to develop a susceptibility rating for foliage, fruit and all pests combined. Cultivars with lowest susceptibility to foliage pests included `GoldRush' and `Pioneer Mac', whereas `Yataka' and `Cameo' were most susceptible. For fruit pests, susceptibility was lowest for `Pristine' and `Sunrise', and highest for `Cameo', `Fuji Red Sport #2', and `Gala Supreme'. When both foliage and fruit pests were combined, susceptibility was lowest for `Sunrise' and `Pioneer Mac', and highest for `Cameo'. Some increasingly popular cultivars had high levels of injury from a few pests, including plum curculio and apple maggot on `Ginger Gold', codling moth and oriental fruit moth on `Cameo', and japanese beetle, plum curculio and apple maggot on `Honeycrisp'. A positive and significant correlation was found between day of harvest and percent fruit injury from codling moth/oriental fruit moth and tufted apple bud moth/redbanded leafroller, with later maturing cultivars experiencing higher injury levels presumably due to more exposure to later generations of these pests. Differences among cultivars in pest incidence and injury can be used by growers to improve pest management through cultivar selection, or by making modifications in control programs based on cultivar susceptibility.