Breeding wheat lines for southern Australia according to three climatic mega-environments

Abstract

One hundred and sixty-one wheat variety evaluation trials from southern Australian for the years 1994, 1995 and 1996 were analysed. Using this and long-term climate data, we show that, on the basis of differences in genotype by environment interaction, the South Australian and Victorian wheat belt may be separated into 3 mega-environments. These are: a Wimmera type environment with 200 to 300mm rainfall between sowing and anthesis and an average maximum temperature of less than 26°C between anthesis and harvest; and for the same respective crop developmental phases a Mallee type environment with less than 200mm rainfall, and an average maximum temperature of greater than 26°C; and a high rainfall environment with more than 300mm rainfall, and less than 26°C. These 3 mega-environments elicit different response patterns of genotypic performance.