Abstract
This paper reports the effects of combine and crop parameters on wheat recovery (Pak-81). Three levels of each
parameters i.e. moisture content, concave clearance and feed rate were selected. Experimental results revealed
that doubling the feed rate at constant concave clearance doubled approximately the total grain losses and
conversely reduced the breakage of threshed grain by 16%. Grain losses at 26% and 13% moisture content were
found higher than those at 19% moisture content at each level of feed rate and concave clearance. Minimum
grain loss of 0.94% was found at 19% moisture content, 30 mm concave clearance and 2.82t!hr feed rate.
However, minimum grain damage was observed at 26% moisture content, 30mm concave clearance and 5.64t!hr
feed rate which was 1.4%. Forward Stepwise Regression Analysis revealed that feed rate was the most important
parameter for causing total grain losses and similarly interaction of moisture content and concave clearance
resulted in maximum grain damage.
Keywords: Combine; concave clearance; feed rate; regression
