RELATIONSHIP OF THE HEIGHT RICE IS CUT TO HARVESTING TEST PARAMETERS

Data were collected from four long-grain rice varieties to develop a r elationship between the height at which rice is when combined and the amount of material other than grain (MOG) above the cut. A quadratic e quation described the relationship between the MOG ratio (MOG above th e cut divided by the total MOG) and the height ratio (height of cut di vided by the plant height) with an R2 value of 99.6% and a mean square error of 0.0004. Using this equation, a procedure is described to est imate the feedrate through a combine for given header widths, combine ground speeds, and crop conditions. The crop conditions that must be i nput are the grain yield, which can be estimated prior to harvest, and the harvest index, which is a physiological parameter that relates gr ain yield to biological yield and which has been reported for many ric e varieties.