Fungicide Resistance in Venturia effusa, Cause of Pecan Scab: Current Status and Practical Implications
- 1 February 2021
- journal article
- review article
- Published by Scientific Societies in Phytopathology®
- Vol. 111 (2), 244-252
- https://doi.org/10.1094/phyto-06-20-0221-rvw
Abstract
Pecan scab, caused by Venturia effusa, is the most economically damaging disease of pecan in the southeastern U.S. and annual epidemics are most effectively managed through multiple fungicide applications. The fungicide applications can be the single greatest operating cost for commercial growers and the return on that investment is impacted by fungicide resistance. Venturia effusa produces multiple generations of conidia per season, exhibits substantial genetic diversity, overwinters as stromata in the tree, and is under immense selection from the applied fungicides, all of which lead to a high risk for developing fungicide resistance. Since the mid-1970s, resistance or reduced sensitivity has been observed in isolates of V. effusa to the methyl benzimidazole carbamates, demethylation inhibitors, quinone outside inhibitors, organotin compounds and the guanidines. Over the last ten years, several studies have been conducted that have improved both scab management and fungicide resistance management in V. effusa. The aim of this review is to summarize recent developments in our understanding of fungicide resistance in V. effusa in the context of scab management in southeastern pecan orchards. The history, modes of action, general use of the labelled fungicides, and mechanisms and stability of fungicide resistance in V. effusa are discussed; conclusions and future research priorities are also presented.Keywords
This publication has 46 references indexed in Scilit:
- Evaluation of a phosphite fungicide to control pecan scab in the southeastern USACrop Protection, 2012
- Deleterious Effect of the Q o Inhibitor Compound Resistance-Conferring Mutation G143A in the Intron-Containing Cytochrome b Gene and Mechanisms for Bypassing ItApplied and Environmental Microbiology, 2011
- A rapid method to monitor fungicide sensitivity in the pecan scab pathogen, Fusicladium effusumCrop Protection, 2010
- Monitoring Fungicide Sensitivity of Cercospora beticola of Sugar Beet for Disease Management DecisionsPlant Disease, 2010
- In vitro toxicity of alternative oxidase inhibitors salicylhydroxamic acid and propyl gallate on Fusicladium effusumJournal of Pest Science, 2010
- Field evaluation of systemic inducing resistance chemicals at different growth stages for the control of apple (Venturia inaequalis) and pear (Venturia pirina) scabCrop Protection, 2009
- Fungicide modes of action and resistance in downy mildewsEuropean Journal of Plant Pathology, 2008
- Influence of Scab on Late Season Nut Drop of PecansPlant Disease, 1983
- Management of Pecan Fruit and Foliar Diseases with FungicidesPlant Disease, 1981
- Biology of Triphenyltin-Resistant Strains ofCercospora beticolafrom Sugar BeetPlant Disease, 1980