Evaluation of Yield Loss In Different Paddy Varieties and Combine Harvester Types in The Manmunai West DS Division Batticaloa District of Sri Lanka

Abstract

This study evaluated the yield loss in different paddy varieties and combine harvester types in the Manmunai West Divisional Secretariat Division of the Batticaloa District, Sri Larrka. The research employed a factorial randornized complete block design (RCBD)',vith tlree rice varieties (Bg 94-1, Bg 366. and Bg374\ and tlree combine harvestermodels (Kubota DC-70G Pro, Yanmar YH 850, and Sumo Stainless), alongside manual harvestin-e as a control. Data was collected on total yield loss- grain rnoisture content, panicle lengfh, and panicle paddy couttt, with all measuren'lents conducted under standardized field and machine conditions. Statistical analyses, includingANOVA, Tukey's HSD, and correlation tests, were performed to determine significant differences and relationships among factors.The results revealed that fotal yield loss ranged befween 3.77% ancl 9.0196, with an overall mean of 6.32aA, indicating that cornbine harvesting under optimal conditions perfonns i,vithin acceptable operational thresholds. Grain moisture content averaged lg.650A,fallin-e witlrin the ideal range {lS-22%) for mechanical harv'esting. Varietal, differences were modest, with Bg 94-1 achieving the highest rnean yield (116.5 g/0.025m2) but slightly greater losses. while Bg 366 and Bg 374 showed balanced performance. Correlation analysis revealed weak" nonsi-enificant associations between total yield loss, panicle length and grain-bearing.The findings underscore the irnportance of matching han'ester settings with varieral characteristics and maintaining optimal field conditions to rninirnize losses. The study contributes practical recorurendations for improving rnechanized harvesting efficiency, reducing post-harvest losses, and enhancing the productivity and profitability of paddy farming in Sri Lanka. Keyi,r'ords: Cornbine harvester, Harr,'est efficiency, Mechanized harvesting, Rice varieties, Yield loss