Key messages
Yield loss from crown rot infection varied among barley and wheat varieties in all three years tested, rangeof 0-1.85t/ha (0-59% yield loss) for barley and 0-1.11t/ha (0-42% yield loss) for wheat.
Understanding the crown rot disease history of a paddock and choosing varieties with the appropriate disease resistance ranking can improve crop yield substantially in the presence of crown rot.
Aims
Determine the relative yield loss of new and commonly grown barley and wheat varieties to crown rot infection in Western Australia.
Results
All barley and wheat varieties had reduced yield in inoculated plots, however, significant differences (P <0.05) were evident between varieties in all years and sites tested.
In the barley trials, La Trobe and Litmus consistently had the lowest yield reductions from crown rot infection. Yield of Bass and Granger were consistently the most heavily impacted by crown rot infection losing up to 59% yield to the disease.
In wheat, the yield of Emu Rock was the least affected by crown rot across most seasons and sites ranging between 0-13% yield loss. Justica CL was the lowest yielding variety under crown rot infection with the highest yield losses of 23-42% across all seasons and sites.
Conclusion
These results show that variety choice under high crown rot disease pressure can have an impact on yield. For example, at Wongan Hills in 2016, with added crown rot inoculum, Emu Rock yielded 0.29t/ha (P <0.001) more than Mace. However, in the plots without crown rot, Mace out-yielded Emu Rock by 0.30t/ha (P <0.001).
Understanding the crown rot disease history of a paddock and choosing varieties with appropriate disease resistance ranking can improve crop yield substantially. It is important to realise that in a year with good rainfall with no or very low levels of disease expression (white heads), inoculum levels can build-up substantially in paddocks with a tight cereal rotation and impact of future crops.