Comparative evaluation of three hermetic storage technologies on post-harvest quality of stored sorghum grains

Abstract

The effectiveness of different storage technologies for sorghum grains under conditions of smallholder farmers were tested at Makerere University Agricultural Research Institute Kabanyolo (MUARIK). Three improved storage methods were used to store either infested or un-infested sorghum grains. These storage methods were: Purdue Improved Crop Storage (PICS) bags, SuperGrain (SG) bags, and plastic bottles. These were compared against the conventional woven polypropylene (PP) bags as the control for grain storage during a period of 90 days. Quality parameters such as grain moisture content, germination, insect mortality, grain damage, and weight loss were measured every 15 days for 90 days. The dominant insect pests identified in the stored grains were Sitophilus granarius. Insect mortality of infested grains reached 100% in PICS bags, SG bags, and plastic bottle by 75 days of storage, while it remained close to 0% for infested grains stored in PP bags. Moisture content, germination, grain damage, and weight loss of sorghum grains stored in hermetic bags in both infested and un-infested grains remained nearly the same at end of storage as they were at the beginning. In the PP bags, grain quality significantly changed in both infested and uninfested grains. In terms of economic analysis, hermetic storage technologies were found to be economically viable as opposed to conventional methods (PP bags) without synthetic insecticide for long-term storage. In conclusion, all the hermetic storage technologies tested were effective in maintaining the integrity of the grains for three months, while substantial-quality deterioration occurred for grains stored in PP bags without any protection.