Effect of sowing time on sweet corn yield and quality

The effects of sowing time on sweet corn yield and quality were examined by sowing three sweet corn (Zea mays L.) hybrids of varying maturity at approximately fortnightly intervals from 21 September 1999 to 20 January 2000. Delayed sowing reduced total crop biomass by 0.86 t/ha per 10-day delay. Harvestable ear yield declined by 1.6 t/ha per 10 day delay in sowing, mainly through reduced mass of harvestable secondary ears. Effects of sowing time on primary cob characters such as length, kernel fill and diameter were minor. There was no consistent effect of sowing time on kernel colour, which differed significantly among hybrids. Kernel toughness was the only component of yield or quality to benefit from a delay in sowing, with kernels becoming more tender in later-sown crops. The effects of genotype on kernel toughness were at least as great as those of sowing time. Given the yield penalty incurred through delayed sowing, it seems likely that quality targets will be more profitably met by careful choice of hybrid than by choice of sowing time. The implications of these findings for improved crop management are briefly discussed.