Fig. 2. Effect of temperature on yield and harvest index. Grain yield was similar across temperatures, but vegetative biomass increased as temperature increased (P = 0.02). As a consequence, harvest index declined significantly (P = 0.0002). Days to heading were longest at 27°C but were about 45 d at 29 and 31°C. Error bars indicate standard error of means (n = 12 for each point). There are no error bars on days to heading because all replicates headed on the same day.