Effect of Different Crop and Operational Parameters of a Combine on Grain Damage During Paddy Harvesting

A study was conducted on a grain combine to find out the effect of different moisture contents, cylinder speeds and feed rates on visible grain damage, invisible grain damage and germination percentage during paddy harvesting. Tests were conducted at three levels of moisture content on wet basis (22%, 19% and 16%), three levels of cylinder speed (18.2 m/s, 20.2 m/s and 22.2 m/s) and three levels of feed rate (24.2 q/h, 33.6 q/h and 61.7 q/h). Visible grain damage, invisible grain damage and germination percentage were observed in the range of 0.6% to 4.1%, 17.6% to 28.0% and 69.8% to 82.3% respectively. Visible and invisible grain damage increased and germination percentage decreased with the decrease in moisture content, increase in cylinder speed and decrease in feed rate. The optimum values of independent parameters within the studied range were found to be grain moisture content 22% (w.b.); cylinder speed 18.2 m/s; and feed rate 61.7 q/h.