Sweet Corn Ontogeny in Response to Irrigation and Nitrogen Fertilization

To achieve optimum quality, sweet corn should be harvested at the milking stage, therefore understanding of plant phenology could be the most important aspects for economic return in this crop. Phenological sensitivity to the environment could be especially important in the management of water and nitrogen. In the current research, sweet corn ontogeny in two years was monitored in response to irrigation and nitrogen fertility: three water regimes and five nitrogen levels. The results showed that nitrogen and water application significantly affected duration in sweet corn between emergence and silking. As nitrogen and water level was increased, the days and cumulative temperature units (TU, °C) from sowing to silking significantly increased. In 2014, sowing to silking ranged from 66 days equal to 1035 TU with deficit water and nitrogen treatment to 72 days equal to 1140 TU at full irrigation and highest nitrogen treatment. In 2015, the range of sowing to silking was from 67 days equal to 1090 TU, to 73 days equal to 1180 TU. In contrast, neither nitrogen nor water treatments had a large influence on the duration of the silking to milking period. Across the two years the duration of silking to milking was approximately 506 TU. Therefore, once silking date had been resolved harvest date of sweet corn could be readily predicted independent of water or nitrogen treatment as occurring about 506 TU following silking.