Abstract
In 2006 and 2007, nine fungicides were evaluated to determine if “practical” fungicide resistance could be identified and if fungicide resistance drift occurred in cucurbit powdery mildew of pumpkin. The fungicides and/or tank mixes whose active ingredient(s) were evaluated included: sulfur (FRAC code M1), chlorothalonil (M5), myclobutanil (3), pyraclostrobin (11), azoxystrobin (11), quinoxyfen (13), chlorothalonil + myclobutanil (M5 + 3), famoxadone + cymoxanil (11 + 27), pyraclostrobin + boscalid (11 + 7), and water only (control). Based on visual ratings of upper and lower leaf surfaces, a FRAC code 11 resistance cucurbit powdery mildew population was present in both years. Practical resistance and cross resistance were identified where a FRAC code 11 fungicide had not been applied season-long as well as where a FRAC code 11 fungicide was applied weekly or in rotation with another fungicide chemistry. Resistance to a FRAC code 3 fungicide was not identified where a FRAC code 3 fungicide had been applied season-long, or in rotation, or where no FRAC code 3 fungicide was applied. This study demonstrates that cucurbit powdery mildew populations resistant and/or cross resistant to FRAC code 11 fungicides can develop and have the potential to disseminate into and be detected in areas where no FRAC code 11 fungicides have been applied. Accepted for publication 11 October 2010. Published 22 November 2010.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
