Crop design for specific adaptation in variable dryland production environments

Climate variability in dryland production environments (E) generates crop production risks. Optimal combinations of genotype (G) and management (M) depend strongly on E and thus vary among sites and seasons. Traditional crop improvement approaches seek broadly adapted genotypes to give best average performance under a standard management regime across the entire production region, with some subsequent manipulation of management regionally in the response to average local environmental conditions. This process does not search the full spectrum of potential G X M X E combinations forming the adaptation landscape. Here we examine the potential value (relative to the conventional broad adaptation approach) of exploiting specific adaptation arising from G X M X E. We present an in-silico analysis for sorghum production in Australia using APSIM sorghum model. Crop design (G X M) is optimised for subsets of locations within the production region (specific adaptation) and is compared with the optimum G across all environments with locally modified M (broad adaptation). We find that geographic sub-regions that have substantially different frequencies of major environment types to that for the entire production region, show greatest advantage for specific adaptation. While the specific adaptation approach confers yield and production risk advantages at industry scale, even greater benefits should be achievable with better predictors of environment type likelihood than that conferred by location alone.