Nutridense corn response to nitrogen rates

Nitrogen rate effects on the grain composition of nutritionally enhanced corn (Zea mays L.) hybrids have not been widely studied. Field experiments were conducted at two Illinois locations and two Ohio locations in 2006 and 2007 to determine if hybrids containing NutriDense (ND) genetics respond to N rates differently than yellow dent (YD) corn hybrids for grain yield, protein and oil content. Twelve ND hybrids and five YD hybrids were evaluated across eight environments at five N rates that varied from 0 to 269 kg ha^-1. There were only two hybrid × N rate interactions across eight site-year environments. The YD hybrids' average grain yields were greater than the ND hybrids in seven of the eight environments (9.6 vs. 8.8 Mg ha^-1). The grain protein and oil content of ND hybrids were greater than the YD hybrids in three of four environments. Averaged across environments and N rates, protein content was 78 and 86 g kg^-1 for the YD and ND hybrids, and oil content was 53 and 56 g kg^-1 for YD and ND hybrids, respectively. Grain yield and protein increased and grain oil decreased slightly as N rate increased from 0 to 269 g ha^-1. Nitrogen rates needed to optimize yield and grain quality of ND corn hybrids are similar to those recommended for YD hybrids.