A Kaolin-Based Particle Film Suppresses Certain Insect and Fungal Pests While Reducing Heat Stress in Apples

Abstract

The application of non-toxic particle films to suppress arthropod pests and diseases in crop plants is a promising recent development in horticulture. Experiments were conducted in two orchards in southwest Missouri to evaluate a specific particle film's effectiveness against such pests in apples [ Malus sylvestris(L.) Mill. var. domestica(Borkh) Manst.]. A newly-developed kaolin-based product, Surround WP (Engelhard Corp., Iselin, NJ), was applied at five different rates and frequencies throughout two growing seasons. The product was successful at suppressing plum curculio ( Conotrachelus nenupharHerbst) damage to fruits, red-banded leafroller ( Argyrotaenia velutinanaWalker) damage to leaves (but not consistently to fruits), flyspeck ( Zygophiala jamaicensisMason) and sooty blotch [ Gloeodes pomigena(Schwein.) Colby] diseases on fruits, and a Phoma leaf spot (Phoma sp.), but was not consistently effective against cedar apple rust ( Gymnosporangium juniperi-virginianaeSchwein). Overall grade of apple was improved with particle film applications. Generally, higher rates and more frequent applications resulted in better pest suppression. The particle film coating also reduced plant stress during extreme temperature conditions. Results suggest that kaolin-based particle films have potential applications in integrated management of apple pests, while providing some physiological benefits to the plants.