EVALUATION OF PLASTIC AND STEEL BINS FOR PROTECTION OF STORED MAIZE AGAINST INSECT INFESTATION IN GHANA

The present study evaluated plastic and steel bins as bulk storage structures for protection of maize against infestation by insect pests in Ghana. The study which spanned the period February 2016 to January 2017 was undertaken in Ejura, located in the Middle Belt of the country. Untreated maize pre-disinfested with a solar biomass hybrid dryer was stored in either a 7-MT white plastic bin or a 7-MT green plastic bin or a 6-MT Kikapu steel bin as experimental treatments. Six 50 kg polypropylene (PP) bags filled with maize treated with Betallic Super (80 g pirimiphos-methyl and 15 g permethrin per liter as an emulsifiable concentrate (EC)) (Check) and six 50 kg PP bags filled with untreated maize (Control) were also maintained. The study was arranged in a completely randomized design. Monthly data on moisture content (MC), insect numbers and damage and mycotoxin levels (aflatoxin and fumonisin) of maize were taken. The dominant insect pest species collected were Sitophilus zeamais, Cryptolestes ferrugineus, Cathartus quadricollis and Tribolium castaneum. Grain mean MC increased slightly in the bins from the initial 12.5% to between 12.6 and 12.9% three months later whereas MC in the control and Betallic treatments decreased to 11.8% and 11.5%, respectively. However, MC increased to between 13 and 14% in all the treatments by the end of the 12-month storage. Percent IDK values in the control and the other treatments were >17% and <3%, respectively at the end of the study. Mean grain weight losses did not exceed 1% in the three bin treatments over the storage period. Unlike the control, mycotoxin levels of the maize in the other treatments were below the recommended threshold. The results of this study show that plastic and steel bins reduce insect pests’ infestation of stored maize and therefore have the potential for use in short to long term storage of grains.