Postharvest Handling Practices and on Farm Estimation of Losses of Sesame (Sesamum indicum L.) Seeds: The case of two Wollega Zones in Ethiopia

Abstract

Sesame is an important crop for the Ethiopian economy. However, poor postharvest handling is a major problem that hampers exporting sufficient volume and quality of the crop. This study was aimed at identifying major causes and critical loss points during postharvest handling practices from maturity of the crop to before storage time. The study was conducted using FAO’s 4S [screening of relevant data, surveying, sampling (load
tracking) and synthesis] approach mainly addressing the assessment and load tracking approaches. The assessment study was conducted in East and Horro Guduru Wollega Zones of Oromia region. Two districts from each Zones and three kebeles from each district were purposively selected and totally 382 sesame producers were interviewed. For load tracking approach to generate objective data, small (<5 hectares), medium (5-10 hectares) and larger (>10 hectares) size farms were selected and estimated losses determined at each postharvest activity. The estimated losses at each postharvest activity were determined in parallel with estimating losses under farmers’ practice. The survey result revealed that the majority of the farmers (55%) use capsule or pod color to determine the right time of harvesting and 90% of them believed that shattering is the major cause of loss during harvest. About 95% of the producers conducted field drying without using plastic or canvases, 90% of them did not use wrapping materials during bundle transport to threshing sites. The results from load tracking indicated that field drying (7.1%), pre-harvest shattering (4.7%), threshing/winnowing (3.5%) and bundle carrying/ transport (1.6%) were major points of loss. The results revealed aggregate loss of 17% only between maturity and storage (excluding storage losses). In conclusion, late harvest, over drying (long duration of field drying), poor transport
mechanisms of the bundles to threshing site, incomplete threshing, and poor winnowing were found to be the major causal factors for high post-harvest loss (PHL) of sesame. Field drying, pre-harvest shattering and threshing activities have been identified as critical loss points, which need technical intervention to tackle the poor postharvest handling practices and minimize the losses.