Investigation into Maize Grain Damage And Detoriation in Crib Storage

ABSTRACT

A study was conducted into the traditional method of storing maize in Ghana to determine the best form of storing maize to minimise losses in storage and to evaluate the effectiveness of using insecticides in crib storage. Two separate experiments were conducted, one with maize variety Abrotia and the other with maize variety La Posta. In each experiment, a split-plot design was used with the main plot factor being insecticide application and the subplot factor being husking. Actellic 2D was the insecticidal dust used. Insect infestation increased with increase in storage period throughout the ten (10) months storage period. Insects identified on the stored maize were Sitophilus zeamais, Tribolium castaneum, Oryzaephilus mercator, Stegobium penicium, Rhizopertha dominica, Prostephanus truncatus and Sitotroga cereallela. S. zeamais was the most prevalent whereas P. truncatus made the least appearance. With maize stored with insecticides, insect infestation on dehusked cobs differed significantly from that of undehusked cobs (P = 0.05). There was no significant difference (P = 0.05) between insect infestation on dehusked and undehusked cobs stored without insecticides. The fungi identified on the stored maize were Aspergillus ochraceus, Aspergillus flavus, Chaetonium globosum. Rhizopus oryzae, Curvularia lunata and Nigrospora sp. Fungal infection was higher on maize stored undehusked compared to those stored dehusked. A. flavus infested mostly undehusked maize and A. ochraceus infested only undehusked maize. Weight loss of maize increased with increase in storage period. Damage caused to maize stored dehusked was not significantly different from those stored undehusked. The germinability of maize declined with increase in storage period. For Abrotia variety it declined from 91% to 0% for both dehusked and undehusked maize stored with insecticide application, from 94% to 1% for dehusked maize stored without insecticide application and from 96% to 0% for undehusked maize stored without insecticide application. The germinability of La Posta variety declined from 95.33% to 0% for dehusked maize and from 94% to 0% for undehusked both with insecticide application. It declined from 95.33% to 0% for maize stored dehusked and from 92.67% to 0% for maize stored undehusked both without insecticide application. From the results of the investigation, dehusked maize could be sorted and the undamaged cobs selected for storage before the application of insecticides. The sheaths of undehusked maize prevent such sorting and selection. For crib storage therefore, maize could best be dehusked and the storage should not exceed four months.