Heat Changes in Maize Storage Influenced by Compound Factors; Different Levels of Maize Weevils, Broken Corn and Foreign Materials, and Moisture Contents

Abstract

Effect of Sitophilus zeamais Mostschulsky infestation on the heat changes of maize at 13, 16, and 19% moisture content with 0, 5, and 10% broken corn and foreign material was studied in 1.81 thermos containers. Containers with infested and uninfested maize were held in a chamber at 26.6°C and 60±5% r.h. for 80 d. Temperatures were measured continuously using a datalogger system. At 13 and 16% moisture content, more grain heating was recorded in infested than in uninfested maize. Presence of insects and moisture content level were major factors in grain heating during storage. Level of BCFM did not significantly affect the grain heating. At 19% moisture content, grain heating increased in all treatments. Heating appeared to be more related to microbial growth than to insect activity, and accumulated to 26.5–37 kj/kg maize at 3–4 wk. The growth of the maize weevil population was significantly affected by grain moisture content. The greatest number of offspring after 80 d was recorded in the 13% moisture content trial. At 19% moisture content, there were more dead than live insects.