Simulated yields of M-206 at a high-yielding site increased by roughly 230 kg ha−1 for each extra day increase in simulation for maturity dates earlier in the season (25–35 d after 50% heading,Fig. 7), though this relationship tapered off as maturity was pushed later in the season. Our determination of physiological maturity(based on a number of heat units following the observed date of R7)resulted in simulations that met our expectations, with observed yields roughly 85% of simulated Yp in most cases.