A cultivar phenology classification scheme for wheat and barley

The relative time to maturity of grain crops is an important consideration for producers, yet there are no universally accepted classification schemes for cultivar phenology to guide decisions on variety selection and time of sowing. A first edition of an industry guide for wheat variety maturity was recently developed for use across Australia, representing a significant step forward for the grains industry. The aim of this paper was to revise and extend this industry guide to make it more robust, agronomically functional and meaningful to industry. The Australian Cereal Phenology Classification (ACPC) presented herein was developed using an unprecedented phenological data set with a diverse array of genotypes, environments and management. Field experiments were carried out with 70 wheat and 30 barley cultivars at 15 sites across Australia between 2017 and 2020. Thermal time to anthesis data were used to rank cultivars according to their relative phenology and divide them into classes, and then boundary cultivars of both species were selected to separate these classes. The resulting classification scheme divides wheat and barley into phenology classes ranging from ‘quick’ to ‘mid’ to ‘slow’. New cultivars to market can be assigned a phenology classification based on their thermal time to anthesis relative to the boundary cultivars. The ACPC will help growers, agronomists, breeders and researchers make informed decisions regarding cultivar comparison and selection while reducing misclassification and confusion across regions. The same methodology used to derive and validate the ACPC can be applied internationally to standardise descriptions of crop phenology.