Crown rot is one of the biggest limiting factors of crop production, with yield losses as high as 60% being recorded in susceptible varieties. The nature of crown rot in the northern grain growing region means that it is extremely widespread, with background levels of the pathogen found in most cropping areas. Crown rot research currently focuses on developing both resistant and tolerant varieties for commercial use. Tolerance testing involves a number of advanced lines being put under plus and minus disease conditions, with the plus being inoculated with crown rot and the minus having no inoculation treatment. However as crown rot is so widespread, there is commonly a base level of the crown rot inoculum already evident within the minus plots, preventing a true zero yield potential value being determined. This dilemma has recently been identified by the GRDC as a significant area of concern for the future of crown rot research as tolerance trials expand and the availability of near zero level disease plots decreases.
Preliminary trials indicate that soil solarisation has the ability to deliver near zero level crown rot reference sites for experimental purposes. When plots were solarised for twelve weeks, a 98.7% reduction in Fpg DNA/g soil was observed, compared with 11.2% and 44.9% in fallow and mungbean plots. A reduction was also seen in infected wheat stubble with only 5.8% of Fpg colonised stubble remaining after the solarisation, compared to 61.9% and 53% in the fallow and mungbean treatments. This project will examine whether soil solarisation is more effective in decreasing crown rot inoculum load between seasons than current stubble management techniques and if it causes any detrimental effects to the following crop due to microbial or nutritional changes to the soil.