Effect of the Thresher Drum Rotary Speed, Distance Between Thresher Drum and Sieve, and Stem Height on Wheat Quality

In this study, the effect was evaluated of thresher drum rotary speed (700, 800, 900, 1000 rpm), distance between thresher drum sieve (8, 10, 12, 14 mm) and stem height (50–60, 61–70, 71–80 cm) on the percent breakage into chipped kernals, half kernels, bits and fine particles. A Lexion 510 class combine harvester was used equipped with GPS and yield monitoring equipment. A randomized complete block design and split factorial arrangement with three replications and a Duncan test was used for statistical analysis. Testing was done at a Pasargad farm in Fars province. Marvdasht variety wheat was planted using an Amazon combinat. The results showed that the drum rotary speed had a significant effect on threshing loss and percentage of damaged grains. The best result was produced by a thresher drum rotary speed of 700 rpm, 10 mm distance between thresher drum and sieve and a stem height of 71– 80 cm.