Sweet corn is one of the important high-value crops in the Columbia Basin, and it requires a significant amount of nitrogen (N) input to achieve the optimal yield target. However, with many varieties planted, the N requirements should be evaluated to ensure the economic and environmental sustainability. In a field trial conducted from May to August in Hermiston, OR, six sweet corn varieties were tested under six nitrogen application rates (ranging from 0 to 308 kg N/ha). The results showed that the optimal N rate for maximizing corn yield and marketable ear number was approximately 247 kg/ha across all tested varieties. Among the varieties, Driver R and Sorel produced the highest yields, the most marketable ears, and relatively longer ear lengths, while Turbine had the lowest yield. Megaton had the highest proportion of non-marketable yield, which may reduce its marketable value, although it produced the longest cobs. Multiple-year evaluation is needed to develop a conclusive recommendation for nitrogen fertilization of sweet corn in the region.
