Survival of conidia of sorghum ergot (caused by Claviceps africana) on panicles, seed and soil in Australia

Abstract

Macroconidia of the sorghum ergot pathogen, Claviceps africana Frederickson, Mantle & de Milliano, survived in dried honeydew on soil for 13–14 weeks in a glasshouse at ambient temperatures, but for less than half that time on seed stored in a shadehouse over summer. Those on seeds stored at 4°C, however, survived for over a year (58–62 weeks). During summer, conidia on ergot-infected panicles buried in soil, or on the soil surface, survived for 7.5–12 weeks, whereas over winter the survival times were 4 weeks and 19–27 weeks, respectively. Macroconidia on infected panicles held above the soil surface survived for >38 weeks (8 calendar months) over winter, suggesting that they may play a role in the perennation of C. africana in Australia.