Optimization of some selected process factors in wheat production: A response surface approach

Abstract

This study applied the approach of Response Surface Methodology to optimize some selected process factors in wheat production in order to minimize the amount of wheat harvest loss using combine harvester. The factors considered were Grain Moisture Content (GMC), Rotor Speed (RS) and Ground Speed (GS) of the combine harvester. The amount of wheat loss was evaluated in different levels of GMC (10, 15 and 20 %), RS (450, 550 and 650 rpm) and GS (3.5, 4.5 and 5.5 km/h) and the relationship between the specified factors and the amount of wheat harvest loss was established. The study revealed that the 2-factor interaction model with coefficient of multiple determination (R^2) and adjusted coefficient of multiple determination (R ̅^2) of 79.5% and 76.88% respectively and an insignificant lack of fit (p value of 0.289) best predicts the wheat harvest loss using combine harvester. In the canonical analysis, the Eigenvalues were 10.83, 4.46 and 1.21 which shows that the points 15% for grain moisture content, 650 rpm for rotor speed and 3.5km/h for machine ground speed are points of minimization which give the least wheat harvest loss. The 3-D surface plot for the wheat harvest loss gave a concave up image justifying the points of minimization obtained. The farmer will recover at least 66kg of wheat per hectare if the recommended factor combination is applied.