Advances in Rice Harvest-to-Storage Technologies in Asia: A Systematic Review

Postharvest losses in paddies frequently occur during harvesting, threshing, drying, storage, and milling.This review aimed to synthesise the available evidence on technologies that address such losses across different postharvest stages.Using the PRISMA framework, we conducted a Scopus search on 18 August 2025 ("postharvest losses" AND paddy).Of the records retrieved, 23 met the inclusion criteria.For each study, we extracted the stage, technology, comparator, study design, and reported outcomes.These outcomes included mass loss, head rice yield (HRY), proportion of broken grains, moisture content (MC), time to reach the target MC, energy or cost per kilogram, insect and rodent damage or mortality, and seed germination.Units were standardized (dry-basis of MC).A random-effects meta-analysis was planned where at least three comparable contrasts were available; otherwise, a structured synthesis was applied.The evidence was strongest for drying and storage innovations.Smallscale recirculating dryers lowered the MC from approximately 20-25% to 11-13% within 4.0-4.7 hours at 39-40°C, whereas bag-bin systems reduced the MC from 35.4% to 8.7-13.4% over 11.7 hours at 39-55.6°C.Engineered drying was cost-competitive in wet seasons (Tk 0.74-0.87kg⁻¹versus Tk 1.00kg⁻¹ for sun-drying), yielding a benefit-cost ratio of 1.9-2.4 with a payback period of under one year.Hermetic storage minimized moisture drift, insect damage, and breakage while increasing seed germination by 11.2 percentage points.RF heating was highly effective against insects, and attractant-or air-assisted traps enhanced capture.Rodent damage at community stores remained significant, although interventions reduced losses (e.g., from 14 to 4% and from 8.2 to 1.2%).At the milling stage, a 12-ton recirculating dryer improved mill capacity utilization from 33.3 to 60%.In summary, a tailored package of stagespecific measures-mechanical threshing, recirculating or fixed-bed drying calibrated by bed thickness, hermetic storage combined with RF or IPM approaches, and coordinated community rodent control-can reduce losses from the usual double-digit levels to low single digits at treated points while improving HRY.Successful scaling will require extension systems that emphasize evidence-based measurement and the mobilization of performance-linked financing (PLF).