Fusarium crown rot of wheat - impact on plant available soil water usage

of crown rot, caused by Fusarium pseudograminearum, is related to moisture and or evaporative stress during grain filling. The impact of the disease on plant soil water use is however, not well understood so we investigated it in the durum variety Caparoi at Walgett in 2012 and both Garah and Rowena in 2013. Neutron probe access tubes were installed in replicated inoculated and uninoculated plots to 1.8 m in each season. Soil moisture was measured in depth intervals at GS30, GS39, GS61, GS80 and GS92. Stress occurred relatively late at Walgett in 2012 due in part to a full starting moisture profile and average early season rainfall and temperatures. Stress occurred earlier at both sites in 2013 with infection impacting on soil water use from GS39 onwards. Crown rot infection prevented extraction of a total of 24 mm of PAW at Garah and 49 mm of PAW at Rowena by harvest. Crown rot infection reduced yield from 3.78 t/ha down to 3.11 t/ha (17.8% yield loss) at Walgett in 2012 with screenings increasing from 6.4% up to 13.2%. At Garah in 2013, crown rot reduced yield by 55.3% (2.20 t/ha down to 0.98 t/ha) with hectolitre weight decreasing from 82.6 kg/hL to 75.5 kg/hL. At Rowena in 2013, crown rot reduced yield by 64.3% (3.32 t/ha down to 1.18 t/ha) with screenings rising from 6.6% up to 19.5%. Crown rot restricts the plants ability to extract PAW which significantly impacts on yield and grain quality.