Poster Presentation Science Protecting Plant Health 2017

Relative benefit of growing bread wheat or barley in the northern grains region in the presence of infection by Fusarium pseudograminearum (#330)

Toni Petronaitis 1 , Steven Simpfendorfer 1 , Rick Graham 1 , Guy McMullen 1
  1. Department of Primary Industries (DPI), Calala, NSW, Australia

Crown rot, caused predominantly by the fungus Fusarium pseudograminearum (Fp), is a major disease of wheat and barley crops in the northern grains region (NGR) of Australia. In the NGR, preliminary studies in 2007 found that crown rot caused an average yield loss of 20% in barley, 25% in bread wheat and 58% in durum. However, the relative benefit of growing barley or wheat under high crown rot pressure in the NGR has not been well established across sites and years. This study determined the relative yield of a widely-grown bread wheat variety EGA Gregory and the dominant malting barley variety Commander in the presence of high crown rot pressure in 32 small plot field experiments conducted between 2009 and 2015 using an uninoculated vs. inoculated (2 g Fp inoculum/m row) trial design. Additional replicated trials were conducted at Tamworth and Garah in 2014 using a wider range of barley and wheat varieties with two sowing dates. Under high crown rot pressure, Commander provided a yield benefit over growing EGA Gregory in 62% of the experiments, EGA Gregory provided a significant yield benefit over Commander in 8% of the experiments, and in 30% of the experiments there was no significant yield difference between varieties. Barley in most experiments and seasons (except the variety Oxford) had improved yield over bread wheat varieties in the presence of crown rot infection. However, late planting cancelled out this yield advantage as crown rot expression in barley is limited by the earlier maturity of most varieties which reduces exposure to evaporative stress during grain filling. Additionally, growing barley under high crown rot pressure can increase Fp inoculum levels as it is very susceptible to infection. Therefore, crop and variety choice should be considered as one element of an integrated management strategy to manage this disease.