Evaluation of kaolin and cinnamon essential oil to manage two pests and a fungal disease of sour cherry at different tree canopy levels

Abstract

We studied the effects of kaolin particle film applications on major sour cherry (Prunus cerasus L.) pests and fruit quality and evaluated the ability of cinnamon essential oil (Cinnamomum verum J. Presl) to reduce infestations by cherry fruit fly, Rhagoletis cerasi (Linnaeus 1758) (Diptera: Tephritidae), in the field. Efficacy of kaolin particle films (Surround WP, Engelhard Corporation; applied at 4% concentration) was compared at two application frequencies (one and two applications). The essential oil of cinnamon (applied at 0.25% concentration) was sprayed five times on selected trees. As the amount of damage caused by pests may vary between different parts of the canopy, both kaolin and essential oil treatments were evaluated at two canopy levels. We found that the damage of R. cerasi and stone fruit weevil, Anthonomus rectirostris (Linnaeus 1758) (Coleoptera: Curculionidae), on the fruits occurred primarily in the upper third of the canopy, while the incidence of sour cherry anthracnose caused by Colletotrichum acutatum J. H. Simmonds 1968 (Glomerellales: Glomerellaceae) was concentrated to the lower third of the canopy. Two kaolin particle film applications significantly reduced the fruit injury caused by R. cerasi by 62% (Abbott’s efficacy). In contrast, the treatments showed no activity against A. rectirostris and C. acutatum, although infestation by A. rectirostris was numerically lower on the trees treated with kaolin (19–32% efficacy). The kaolin applications did not affect the average fruit weight (g/100 cherries) and soluble solid content (SSC, %). The cinnamon essential oil applications did not control infestations by R. cerasi. Overall, our results suggest that kaolin particle film technology is a promising tool in pest management programs in organic sour cherry production, at least against R. cerasi.