Suppression of Monilinia Blight: Strategies for Today and Potential Fungicide Options for Tomorrow

Abstract

Fungicide efficacy field trials were conducted in Nova Scotia and Prince Edward Island during the 2009 growing season to address concerns over: (i) the possible tolerance of the fungal pathogen [Monilinia vaccinii-corymbosi (Reade) Honey] causing Monilinia blight or mummy berry to presently registered fungicides; (ii) increasing scrutiny of specific fungicides by end users; and (iii) the challenge of trying to apply a curative fungicide in a timely manner after an infection period has likely occurred. Results indicated that the active ingredients propiconazole (Topas® and Orbit®), prothioconazole (Proline®), and penthiopyrad (LEM17) were very effective in suppressing Monilinia blight, tolerance to propiconazole did not appear to be present, and the use of multiple active ingredients with different modes of action and persistence also provided excellent suppression. In addition, the treatments had a profound influence on berry yield with the propiconazole, prothioconazole, and penthiopyrad treatments having berry yields that were 73.6, 111, and 112% greater than the untreated control, respectively, at the Nova Scotia site. However, these berry yield results need to be viewed with caution given the known suppressive attributes of some of these fungicides to other diseases present during Monilinia infection periods. © 2012 Copyright Taylor and Francis Group, LLC.