LAUSR

Abstract The current study evaluated the development and growth of three major rapeseed genotypes (Hyola308, Hyola401, and RGS003 as early-, mid-, and late-maturity genotypes, respectively) as well as seed yield under different irrigation regimes (full irrigation, withholding irrigation at the flowering stage, withholding irrigation at the pod initiation stage, and withholding irrigation at the seed filling period) and also the spatial yield potential. APSIM-Canola model was applied to investigate the response of rapeseed genotypes to irrigation regimes in ten locations. Simulated results indicated that yield potential for rapeseed production was higher in the west which is a temperate agro-climatic zone (2852.6 kg ha−1) than in the southwest which is a hot agro-climatic zone (1885.1 kg ha−1). Although Hyola401 (the mid-maturity genotype) had the maximum seed yield (2798.4 kg ha−1), RGS003 (the late-maturity genotype) was found to be more drought-resistant due to a lower decrease in seed yield (18.1 %) under water-limited conditions compared with full irrigation conditions. The current findings suggest that the mid-maturity genotype has more yield potential in the studied locations (with different climates and soils) under full irrigation conditions due to higher seed yield, and the late-maturity genotype can be suggested as a resistant genotype for future breeding programs to introduce new-high-yielding genotypes with high drought tolerance, especially in drought-prone environments. Furthermore, withholding irrigation at seed filling onwards, which showed the lowest decrease in seed yield (13.6 %), can be recommended as a strategy for water-saving at the end of the growing season, and farmers can allocate irrigation water to other crops.