Skip to main content
ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #346962

Research Project: Mitigating Alternate Bearing of Pecan

Location: Fruit and Tree Nut Research

Title: Efficacy of a single late-dormant application of mineral oil plus chlorothalonil for control of peach scab, caused by Venturia carpophila

Author
item Glenn, Thad - University Of Georgia
item Brannen, Phillip - University Of Georgia
item Bock, Clive
item Hotchkiss, Michael - Mike
item Pitts, J - Auburn University
item Sikora, E.j - Auburn University

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/17/2017
Publication Date: 12/1/2017
Citation: Glenn, T., Brannen, P.M., Bock, C.H., Hotchkiss, M.W., Pitts, J., Sikora, E. 2017. Efficacy of a single late-dormant application of mineral oil plus chlorothalonil for control of peach scab, caused by Venturia carpophila. American Phytopathological Society Annual Meeting. 107: S5.41.

Interpretive Summary:

Technical Abstract: Peach scab, caused by Venturia carpophila, is a major disease of peach across the southeastern United States. In multi-year, multi-site field trials, mineral oil plus chlorothalonil late-dormant treatments suppressed both scab incidence and severity, as previously reported for almond scab in California. When applied alone, mineral oil plus chlorothalonil reduced disease incidence and severity by 28.2 and 47.2%, respectively, as compared with an untreated check. A second series of experiments determined whether a late-dormant application of mineral oil plus chlorothanonil, as part of a full-season fungicide program, would substitute for a missed chlorothalonil application at the shuck split phenology (a critical infection period for scab); this would at times have value (e.g. when rainy conditions make shuck split sprays impossible). Although late-dormant applications of mineral oil plus chlorothalonil did not fully substitute for a missed shuck split chlorothalonil spray, a mineral oil plus chlorothalonil treatment resulted in an average reduction in disease incidence and severity of 28.0 and 33.3%, respectively, compared with the treatments in which shuck split treatments were removed from a full-season fungicide program. These results are important in that most peach growers already apply oil for scale insect control, so for a relatively small cost, the addition of chlorothalonil in a tank mix with mineral oil could provide better overall scab management.