In 2018 charcoal rot in sorghum was found to be a big problem in the Darling Downs in southern Queensland, where a lot of disease and a lot of lodging associated with the disease was observed. As a result, the summer crop pathology team led by Adam Sparks at the University of Southern Queensland have been looking at the aggressiveness of the different isolates involved.
The team has undertaken paddock surveys where samples are taken from affected crops, brought back into the lab where isolates can be created and then plants in the glass house inoculated. Observations can then be made to detect differences in disease severity caused by these isolates, and to date, differences in their aggressiveness have been observed.
Drs. Neeraj Purushotham and Niloofar Vaghefi are moving to the genetic level to see how these pathogens vary across northern NSW, southern Queensland and central Queensland as it is known there are differences between the levels observed in these areas, when they undertake surveys. For example, the most recent survey showed southern Queensland had issues with charcoal rot, with central Queensland displaying minimal disease while the previous year there was more severe disease in every paddock surveyed in central Queensland.
Where to next….
The next part of this work is trying to validate the PreDicta®B soil test for Macrophomina phaseolina (the fungus that causes charcoal rot) population levels across the GRDC Northern Region where sorghum is grown. Dr. Dante Adorada from USQ is currently preparing to conduct pre-season sampling of growers’ paddocks to get the pathogen population levels. At the end of the season before harvest, he and his team will revisit and take observations on the amount of charcoal rot and lodging in the sorghum. This information will be used to help SARDI with the PreDicta®B test result recommendations by linking the pathogen soil population levels to end of season disease incidence and lodging.
GRDC Communities Podcast – Last season’s summer grain diseases & sorghum charcoal rot
Dante Adorada and Niloofar Vaghefi from the University of Southern Queensland