Pests and diseases


Crown rot and barley yellow dwarf virus are major diseases of Australian cereal crops, causing significant losses in the grains industry. The industry faces considerable uncertainty around how elevated carbon dioxide (eCO2), higher temperatures and extreme climate events will influence pathogen prevalence, insect behaviour and interactions with the crop.

Project outline

Crown rot

Wheat lines were grown at the AGFACE facility under ambient CO2 (384 mol/mol) and eCO2 (550 mol/mol) to determine if eCO2 influenced the severity of the fungal disease crown rot (CR), the resistance to the disease across genotypes, and disease interactions with grain yield and quality.

Barley yellow dwarf virus

A series of experiments were conducted in growth chambers, greenhouses and the AGFACE facility to determine the impact of eCO2 on the aphid Rhopalosiphum padi (R. padi), which is the main vector of barley yellow dwarf virus (BYDV) in southern Australia.


Crown rot

Crown rot will remain a significant challenge to wheat production and may become more severe under eCO2 conditions:

Barley yellow dwarf virus

BYDV and its aphid vector are expected to increase in severity under future climates with increased CO2 and temperatures:

Next steps

Crown rot

Overall, the results suggest that crown rot severity will increase with rising CO2, reducing yields and potentially increasing the severity of more aggressive strains. Breeding programs for resistant lines will need to continue but current practices appear to be effective under future eCO2 conditions.

Further research is required to address the following questions:

  1. How will the combined effect of warming and eCO2 impact on CR pathogens and host-plant resistance
  2. How will the gradual rise in CO2 and temperature interact with drought to influence yield and quality of CR-infected crops?
  3. How will pathogens behave and evolve in farming systems under warming and eCO2 over several seasons of monoculture / rotation?

Barley yellow dwarf virus

These results may have important implications for the epidemiology of BYDV under future climates in Australia. Ongoing studies in the AGFACE and in chambers incorporate wheat cultivars with different tolerances to BYDV hosts as well as temperature interactions. Future research should also include other cereal crops and different agronomic practices to better understand the pest and disease interactions.

Related resources

Titlesort descending Excerpt
AGFACE fact sheet (2014) Fact sheet profiling the project Australian Grains Free Air Carbon dioxide Enrichment program.
Piotr Trebicki - AGFACE results: pests and diseases Presented by Piotr Trebicki, DEPI, at the AGFACE Crop Science Workshop. 
Piotr Trebicki - BYDV and climate change: why important? (poster) Presented by Piotr Trebicki, DEPI, at the AGFACE Crop Science Workshop