Non-Chemical Preservation Methods for Stored Paddy Rice In Northern Nigeria

Abstract

Effective reduced-risk storage technologies are now available for preservation of paddy rice. In an 18-month study, the effectiveness of six storage methods for controlling of insect pests and preservation of nutritional quality of paddy were evaluated. The preservation methods used were: ZeroFly® Combi bag, PICS bag, Polyethylene-Lined Polypropylene bag, NSPRIDUST® (diatomaceous earth-based product), Permethrin (Rambo™), and a polypropylene bag (Control). The study was conducted in storehouses located in two grain markets in North Central Nigeria: Ita-Amo market in Ilorin, Kwara State and Mokwa modern market in Mokwa, Niger State. Nine bags of 50 kg paddy rice were assigned to each treatment in each storehouse. Every six months, three bags from each treatment were destructively sampled and tested. Insect population levels were higher P < 0.05 in the Control (111.0±22.3) compared to other storage methods. The most common insect species observed were Rhyzopertha dominica, Liposcelis spp. and Tribolium castaneum. The Control had significantly higher IDK (0.8%) and WL (1.2%) compared to other treatments. The Combi, PICS, and NSPRIDUST treatments maintained 98% germination, while the Control had 22.1%. The mean aflatoxin levels in all treatments (2.1-3.8 ppb) were below the 20 ppb threshold. The data indicate that hermetic bags (PICS, ZeroFly® Combi and Polyethylene-Lined Polypropylene), NSPRIDUST and permethrin when used appropriately can effectively reduce quantitative losses and preserve the nutritional quality of paddy rice. The adoption of hermetic bags and DEs for paddy rice storage should be promoted to enhance rice availability and food security in developing countries.