Effect of Cultivar, Nitrogen Rate, and Harvest Moisture on Rice Yield and Quality.

In rice (Oryza sativa L.) agriculture, grain yield and milling quality are important factors, which determine the economic return from a given production area. This is due to the fact that the market value of rice is not just determined by total rough rice yield but also by percent head rice yield. No known research has investigated rice yield and quality of current cultivars produced in the midsouthern United States as affected by nitrogen rate and harvest moisture. Thus, the objective of this study was to investigate current long-grain rice cultivars (standard stature, semi-dwarf, and hybrid) with multiple N rates (0, 45, 90, 135, 180 kg ha^-1) harvested at three moisture contents (low, medium, and high). Research was conducted during the 2012 and 2013 growing seasons with grain moisture determined for harvest sampling at low, medium, and high moistures with percent milled rice yield and percent head rice yield subsequently determined. Rough rice grain yield for all three cultivars was maximized at approximately 134 kg N ha^-1. In general, little difference was observed in percent milled rice yield across N rates and cultivars. In contrast, nitrogen rate resulted in differences in percent head rice yield, particularly at the low harvest moisture content. In the current study, cultivar, N rate, and harvest moisture had minimal impact on percent milled rice yield, but these factors may result in large differences in percent head rice yield. As economic returns are determined by rough rice yield as well as head rice yield, continued research investigating cultivar, N rate, and harvest moisture will help refine harvest, drying, and storage management strategies for rice producers.