Field Performance Evaluation of Different Rice Threshing Methods

Abstract

Threshing oper ation is one of the important an d effective factors on quality an d quantity of padd y. In this stud y,
effects of four t hreshing methods namely power tiller-op erated (T1), axial-flow thresher (T 2), tractor-type thresher (T3)
and combine harvester as a t hresher (T4) on unth reshed grain, shattering loss, damaged grain and broken ri ce at milling
stage were investigated. The results showed tha t there was a significant difference between means of unthreshed grains
and shattering losses in different threshing methods. The highest value of unthreshed grain of 0.56% was in T4 and it was
lowest in T 1 with the av erage of 0.46%. Th e highest shattering loss was obtained in T 2 with an average of 0.59 %. The
amounts of broken and hulled paddy in T1, T2, T3, and T4 were 0.9, 1.59, 2.46 and 2.98%, respectively. The percentage of
broken rice after milling of paddy obtained using T1 was lowest with mean of 17.15% and that of T4 was maximum value
of 25.05%. The percentage of broken white rice using T 2 and T3 was 19% and 22.28%, respectively. It can be concluded
that the quality losses in different threshing methods were more determinant than quantity losses.