The trial aims to create an integrated disease management strategy for STB in the medium rainfall zone.

Two trials were hosted at Hart in 2022, assessing the (1) impact of variety selection, and (2) fungicide timing and management strategies.

• Conditions at Hart in 2022 were conducive for moderate infection levels of septoria tritici blotch (STB) due to high volumes of regular spring rainfall.
• Wheat varieties rated MSS or above performed best at reducing disease severity at Hart in 2022. Variety resistance did not affect grain yield with a trial average of 3.51 t/ha.
• Septoria tritici blotch infection decreased test weight (kg/hL) and increased screenings (%) in the variety resistance trial. Test weight was also reduced in the fungicide timing trial where a GS 39 foliar fungicide was not applied.
• In the fungicide timing trial, treatments with foliar fungicides at both GS 31 and GS 39 increased grain yield by 0.57 t/ha when compared to no fungicide or seed treatment only.
• Fungicide treatments applied as foliar spray at GS 31, foliar spray at GS 31 + GS 39 and seed treatment + Foliar spray at GS 31 + GS 39, reduced disease infection levels to 2-8% in the fungicide timing trial. Foliar spray at GS 39 did not reduce disease (20%) when compared to the nil (23%).

The variety resistance trial was a randomised split plot design with six replicates, six wheat varieties and two treatment blocks of +/- disease.

The fungicide timing and yield loss trial was a randomised block design with six replicates and six fungicide treatments that were applied on Scepter wheat, a susceptible variety to STB.