Paper presented at American Peanut Research and Education Society, 2013 Annual Meeting.
Post-infection activities of fungicides against Cercospora arachidicola of peanut (Arachis hypogaea)†
Article first published online: 28 NOV 2013
© 2013 Society of Chemical Industry
Pest Management Science
Volume 70, Issue 8, pages 1202–1206, August 2014
How to Cite
Johnson, R. C. and Cantonwine, E. G. (2014), Post-infection activities of fungicides against Cercospora arachidicola of peanut (Arachis hypogaea). Pest. Manag. Sci., 70: 1202–1206. doi: 10.1002/ps.3671
- Issue published online: 1 JUL 2014
- Article first published online: 28 NOV 2013
- Accepted manuscript online: 24 OCT 2013 01:07PM EST
- Manuscript Accepted: 24 OCT 2013
- Manuscript Revised: 17 OCT 2013
- Manuscript Received: 21 AUG 2013
- Cercospora arachidicola;
- early leaf spot
Despite strong indirect evidence of post-infection activity by a selection of systemic fungicides against Cercospora arachidicola, the causal organism of early leaf spot of peanut, direct post-infection activities in this pathosystem have yet to be reported in detail. This study was conducted to describe the activities of pyraclostrobin, penthiopyrad and prothioconazole on early leaf spot when each fungicide was applied after pathogen penetration began and throughout the incubation period.
Most C. arachidicola penetration events occurred between 3 and 5 days after inoculation (dai), and the mean incubation period was 11.8 dai. Post-infection activities of the systemic fungicides were similar for all dependent variables measured. Systemic fungicides reduced lesion density compared with the non-treated control when applied at 3, 5 and 7 dai, and disease severity was >60% less for leaves treated with a systemic fungicide at all application dates (3, 5, 7, 9, 11 and 13 dai).
Pyraclostrobin, penthiopyrad and prothioconazole showed similar systemic mobility within peanut leaves and activities against C. arachidicola, and appear to completely arrest the development of the pathogen at least 2 days post penetration, and limit pathogen colonization even when applications occur after symptom onset. © 2013 Society of Chemical Industry