Fig. 3. Relationship between kernel number per plant and plant growth rate during a 30-d period bracketing silking for maize hybrid Asgrow 777 growing with and without fertilization in three growing seasons with different water availability during the period bracketing silking (Exp. 5a, 5b, and 5c). Plants did not show prolificacy, so kernel number per plant was equal to kernel number per uppermost ear. Each point is the average of four replications. The control corresponds to fertilized treatments in the wettest year (Exp. 5b). Reduced N corresponds to non fertilized treatments in the wettest year (Exp. 5b). Reduced W corresponds to fertilized treatments in the years with lowest and intermediate available water (Exp. 5a and 5c). Reduced N and W corresponds to non fertilized treatments in the years with lowest and intermediate available water (Exp. 5a and 5c). Inverse equations were KNP = 667-705/PGR (R² = 0.99, n = 4) for variable N at high water availability; KNP = 699-837/PGR (R² = 0.92, n = 6) for variable available water in fertilized treatments and KNP = 699-862/PGR (R² = 0.95, n = 6) for variable water and N supply. Standard error of the means varied from 0.11 to 0.26 g d^-1 for PGR and from 15 to 16 kernels for KNP.