Evaluating rice losses in various harvesting practices

ABSTRACT: Field performance of five different harvesting methods were assessed on randomized complete block design with four replications which included three indirect harvesting methods of (i) hand cutting + threshing by a tractor driven thresher (T1), (ii) rice reaper + threshing by a tractor driven thresher (T2), (iii) rice reaper + threshing by universal combine harvester equipped with pick-up type header (T3), and two direct harvesting methods of (iv) head-feed rice combine, and (v) whole-crop rice combine. Results revealed that the maximum and minimum effective field capacity were for whole-crop combine (0.361 hah-1) and hand cutting (0.009 hah-1), respectively. Quantitative losses (grain and panicle shattering) in harvesting and threshing obtained to be 2.58% and 2.33% in average on indirect harvesting (T1, T2 and T3) and direct harvesting (T4 and T5), respectively which were not significant statistically. The average qualitative losses (broken, husked and cracked grains) were 2.30% for indirect harvesting and 0.61% for direct harvesting that showed a decline of 63.3% compared to indirect harvesting. Total harvesting losses were 5.07% for T3 (maximum) and 2.74% for T4 (minimum). The harvesting method affected percentage of broken rice after milling significantly. The average broken rice for T1, T2 and T3 was 23.72, 23.28 and 24.56% respectively which were significantly higher than T4 (21.05%) and T5 (20.87%). Also, in the view of loss reduction, applying rice combine harvesters had priority respect to indirect harvesting methods.