Identification of agro-phenological traits of lentil that optimise temperature and water limited flowering time and seed yield

This study aimed to identify the optimal flowering times to maximise yield of lentil in current growing regions and areas of potential expansion of this crop in Australia. We used the validated APSIM-lentil model and identified critical reproductive periods matching minimum risk of abiotic stresses and then applied an ideotype breeding approach coupled with improved agronomic practices that maximise yield of lentils. Sowing windows defined between early -April and early -May were matched with optimal flowering periods (OFP). Optimum yield varied within the environments (2.64-4.64 t/ha) and was associated with OFP. Based on cumulative frost, heat, and water stress, 1750 environments were clustered into low -risk, medium -risk and high -risk categories corresponding to pre- and post-OFP. Overall, sowing later than the optimal sowing window significantly reduced yield of lentils across environments in all regions. For each week delay in sowing beyond the optimal window, yield was predicted to reduce by up to 49 kg/ha across the environments. Based on the association between phenological traits and seed yield, we developed fourteen new lentil ideotypes to target abiotic production constraints. In most cases, the predicted peak mean yields for the ideotypes were greater than that of a high yielding commercial variety across a wide range of production environments. The early -sown ideotypes provided maximum optimal yield advantage of 12-29% over a commercial variety across the three clusters. These results show that by coupling phenological traits with agronomic practices, a significant advantage in yield of lentils for specific environments under abiotic production constraints can be achieved. This model therefore can be used as a decision -making tool by growers, breeders, and agronomists to select improved varieties of lentils in combination with sets of critical phenological traits and suitable sowing times that minimise the impacts of frost, heat, and water stress.