A recent focus of wheat breeders in Australia has been on developing longer maturity varieties. These phenologically slower varieties can be sown earlier in the year to harvest moisture over a longer growing season and still flower in the optimum flowering window.

However, a changing global climate is shifting rainfall out of autumn, when it is required for sowing and enabling good establishment, and into early winter. This shift in the autumn break is forcing more growers to sow dry in order to cover increasingly larger sowing operations and resulting in poor emergence and subsequent grain yields.

Furthermore, herbicide resistant weed populations are increasing globally, requiring more time to control weeds between seasons with double-knock herbicide applications and other alternate strategies. The proposed 100-day wheat ideotype would be sown mid-winter, and then grow and develop rapidly to enable optimum timing of flowering and profitable yields.

Broadscale field experiments across multiple years at Merredin, Yanco, Wagga Wagga, and Narrabri have evaluated over 100 pre-breeding, highly early vigorous wheat lines. Experiments conducted at Wagga Wagga in 2021 and 2022 experienced wetter than normal conditions with excellent rainfall, and minimal harmful frosts compared to an average season.

In these conditions when sown mid-winter, some pre-breeding lines yielded significantly higher than current commercial lines. The traits these lines possess will be presented as examples of an ideal ideotype of a late-sown short-season wheat for Australia. Such an ideotype will provide breeding companies with a list of identified plant traits for introgression into a commercially viable wheat variety.