Relative Susceptibility of New Apple Cultivars to Arthropod Pests

Abstract

<jats:p>As part of a regional NE-183 project (Multidisciplinary Evaluation of New Apple Cultivars), 23 apple (<jats:italic>Malus</jats:italic> ×<jats:italic>domestica</jats:italic> 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.</jats:p>

Differential susceptibility and suitability of domestic and wild apple species for a florivorous weevil and its parasitoids

“…The use of resistant cultivars that are less susceptible to herbivores (direct resistance) or that are supporting biocontrol agents (indirect resistance) is a promising alternative approach for pest control (Wearing et al. ; Hogmire and Miller ; Smith and Clement ). Concerning common diseases such as scab (caused by Venturia inaequalis ), fire blight ( Erwinia amylovora ) or mildew ( Podosphaera leucotricha ), cultivars expressing resistance have already been employed successfully, substantially reducing fungicide applications (Fischer and Fischer ).…”

“…Concerning common diseases such as scab (caused by Venturia inaequalis ), fire blight ( Erwinia amylovora ) or mildew ( Podosphaera leucotricha ), cultivars expressing resistance have already been employed successfully, substantially reducing fungicide applications (Fischer and Fischer ). Considering resistance to herbivores, however, hardly any appropriate cultivars are commercially available (Hogmire and Miller ; Stoeckli et al. ), although several studies have addressed resistance of different apple cultivars to arthropod herbivores including the apple blossom weevil Anthonomus pomorum (Curculionidae) (Kalinová et al.…”

“…) and the codling moth Cydia pomonella (Tortricidae) (Goonewardene et al. , ; Hogmire and Miller ; Stoeckli et al. , ).…”

“…Concerning common diseases such as scab (caused by Venturia inaequalis), fire blight (Erwinia amylovora) or mildew (Podosphaera leucotricha), cultivars expressing resistance have already been employed successfully, substantially reducing fungicide applications (Fischer and Fischer 2002). Considering resistance to herbivores, however, hardly any appropriate cultivars are commercially available (Hogmire and Miller 2005;Stoeckli et al 2011), although several studies have addressed resistance of different apple cultivars to arthropod herbivores including the apple blossom weevil Anthonomus pomorum (Curculionidae) (Kalinov a et al 2000;Mody et al 2015), several aphid species (Aphididae) (Miñarro and Dapena 2007;Stoeckli et al 2008a) and the codling moth Cydia pomonella (Tortricidae) (Goonewardene et al 1975(Goonewardene et al , 1979Hogmire and Miller 2005;Stoeckli et al 2008bStoeckli et al , 2009a). Furthermore, genes and quantitative trait loci (QTLs) for pest resistance in apple were identified for future markerassisted breeding of resistant cultivars (Roche et al 1997;Wearing et al 2003;Bus et al 2008;Stoeckli et al 2008cStoeckli et al , 2009a.…”

“…Firstly, host-herbivore relationships are complex and often still poorly understood, which challenges identification of heritable phenotypic traits that putatively drive resistance (Henery 2011). Secondly, a wide range of herbivore species is involved with specific requirements that would have to be combined to achieve general tree resistance (Hogmire and Miller 2005). And lastly, additional external factors including soil type and climate may affect tree resistance (Stoeckli et al 2008a), rendering predictions concerning herbivore resistance difficult to achieve (Henery 2011).…”