An integrative approach to understanding the pest and disease threats to agricultural biosecurity under future climates

22 - 24 September 2009

Despite increasing knowledge of the predicted impacts of climate change, the potential threats to agricultural biosecurity remain uncertain. In this study, models have been developed to better predict the responses of pest and disease threats to our changing climate. By coupling host-plant physiology, virus and vector population growth and climatic data with projected climate change conditions, we are able to predict individual species responses and shifts to historic geographic ranges. Strengthened by empirical data, these models are intended to be incorporated into plant biosecurity management and contingency planning, forming the basis of integrated scenario-based decision support systems for emergency pest and pathogen management. Current work focuses on developing an innovative spatial modelling environment using the bird cherry-oat aphid (Rhopalosiphum padi) which vectors Barley yellow dwarf virus (BYDV). The effect of climate change on aphid feeding behaviour, flight time and synchrony with the crop, virus acquisition and transmission rates and wheat phenology changes and physiological responses are being incorporated.

Experiments in the Australian Grains Free Air Carbon Dioxide Enrichment (Ag FACE) research facility have enabled field based investigations of the effects of elevated (e) CO2 on wheat pathosystems. Wheat stripe rust (Puccinia stiiformis) and crown rot (Fusarium pseudograminearum) severity, latent period, fecundity and host resistance was assessed under ambient and 550ppm CO2. While no effects of the treatment were observed with P.striiformis over two seasons, an increase in F.pseudograminearum biomass under eCO2 has been observed in 2008. Our integrated modelling and field based approach to resolving the likely effects of climate change to plant biosecurity will be presented.