Harvest date influence on dry matter yield and moisture of corn and stover

Harvest date greatly affects the biomass yield, moisture, and quality of corn and stover. Traditionally, corn and stover have been harvested at lower moisture levels. However, corn stover and grain can be more effectively utilized as animal feed and biomass-ethanol feedstock if they are collected before in-field dry down. This study determined dry matter yield, moisture content, and quality of corn and stover before, during, and after grain maturity in central Illinois. The two-year average kernel moisture was 37.4% (w.b.) when reaching physiological maturity. At the same time, the average stover moisture was 67.7% (w.b.). The dry matter yield of grain increased rapidly until reaching grain maturity and remained relatively stable after grain maturity, with an average yield of 11.2 t ha-1 over the two-year study. For corn stover, the two-year average dry matter yield was 14.71 ha-1 at the beginning of the study filling stage), and it decreased to 13.2 t ha-1 at grain physiological maturity and further decreased to 11.0 t ha-1 throughout grain dry down. During grain dry down, the moldy kernel percentage increased from 2.1% to 4.1% and the stalk lodging percentage increased from 1.2% to 3.6%. The results of this study showed that early harvest of corn and stover at grain maturity has several advantages: higher dry matter yield of stover, lower moldy kernel percentage, and fewer plant lodgings.