The susceptibility of new wheat varieties to the Late Maturity alpha-Amylase (LMA) defect is a key concern for breeding programs developing high-quality milling grade wheat in Australia. A capacity to characterise and quantify actual LMA risk at field scale remains a crucial outstanding industry issue. The overarching aim of this project is to develop a LMA risk model from measured data collated for: field trials with four times of sowing, for 24 genotypes, at 6 locations, for two seasons across the Australian wheat belt. Detailed research field trials linked directly with an LMA simulation modelling approach will be valuable to better quantify LMA triggers at field scale and assist with modelling actual LMA risk across the Australian wheat belt.

This will be achieved through targeted time-of-sowing field trials, which will include early sowing dates to capture the required weather and crop development data needed for:

1. characterising the environmental conditions that may trigger LMA in a wide range of Australian germplasm under Australian field conditions, and

2. developing a process based LMA risk model incorporating detailed phenology and environmental conditions to predict actual field risk at a shire level.

   Results of these developments will allow:

3. better quantification of the actual risk of LMA incidence at field scale,
4. generation of seasonal diagnostic data to identify likely LMA hotspot regions, and
5. better management of breeding systems to support genetic gain for yield while managing LMA risk.