Patterns of release of the secondary conidia of Claviceps africana, the sorghum ergot pathogen in Australia

Ryley, M. J. and Chakraborty, S. (2008) Patterns of release of the secondary conidia of Claviceps africana, the sorghum ergot pathogen in Australia. Plant Pathology, 57 (3). pp. 473-483. ISSN 0032-0862

Abstract

Trials were conducted in southern Queensland, Australia between March and May 2003, 2004 and 2005 to study patterns of hourly and daily release of the secondary conidia of Claviceps africana and their relationships with weather parameters. Conidia were trapped for at least one hour on most (> 90%) days in 2003 and 2004, but only on 55% of days in 2005. Both the highest daily concentration of conidia, and the highest number of hours per day when conidia were trapped, were recorded 1-3 days after rainfall events. Although the pattern of conidial release was different every day, the highest hourly conidial concentrations occurred between 10.00 hours and 17.00 hours on 73% of all days in the three trials. Hours when conidia were trapped were characterized by higher median values of temperature, windspeed and vapour pressure deficit, lower relative humidity, and leaf wetness values of 0%, than hours when no conidia were recorded. The results indicate that fungicides need to be applied to the highly ergot-susceptible male sterile (A-) lines of sorghum in hybrid seed production blocks and breeders' nurseries as soon as possible after rainfall events to minimize ergot severity.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2008 Department of Primary Industries and Fisheries. Published version deposited in accordance with the copyright policy of the publisher.
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 13 Jun 2014 05:15
Last Modified: 18 Aug 2014 06:23
Uncontrolled Keywords: hybrid sorghum production; sorghum bicolor; spore-trapping; weather-related spore release
Fields of Research : 06 Biological Sciences > 0603 Evolutionary Biology > 060307 Host-Parasite Interactions
06 Biological Sciences > 0605 Microbiology > 060505 Mycology
07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070308 Crop and Pasture Protection (Pests, Diseases and Weeds)
Socio-Economic Objective: B Economic Development > 82 Plant Production and Plant Primary Products > 8204 Summer Grains and Oilseeds > 820404 Sorghum
Identification Number or DOI: 10.1111/j.1365-3059.2007.01819.x
URI: http://eprints.usq.edu.au/id/eprint/25297

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