Abstract:
Hermetic storage is one of the cost effective, safe pests controlling method used by most of the
grain farmers in the world. In Sri Lanka, maize weevil is one of the common pests affect for the
stored maize and banning of pesticides during previous years caused to a vast problem for
farmers. So, the current research studied the practical aspects of the hermetic storage of maize,
because farmers usually open the storing structures during the storage period of grains. 5 L
bottles were used as hermetic structures. Cleaned, dried (until 13 % moisture content), newly
harvested maize seeds were filled into the 5 L bottles, keeping small space for air. For the
emergence of F1 generation, unsexed maize weevils were artificially infested into separate small
sized plastic containers with maize seeds. And after 7 days adult weevils were removed and after
21 days F1 generation will be emerged. Then emerged adult weevils (30 weevils) were artificially
infested into hermetic containers and sealed the containers. Three treatments were taken for the
study. T1, T2 and T3 indicate the treatments respectively, opening the hermetic sealing weekly,
biweekly and control. For each treatment three replicates were used. In every opening containers
were opened for 10 mins. The study was conducted until 6 months. Each week, the concentrations
of carbon dioxide (CO2) and oxygen (O2) were determined using gas chromatography. Treatment
1 had the highest mean oxygen concentration (14.83±5.76), while treatment 3 had the lowest
mean oxygen concentration (10.85±3.29). Treatment 3 had the highest mean carbon dioxide
concentration (9.11±3.37), while treatment 1 had the lowest mean carbon dioxide concentration
(7.32±4.30) And the evaluated results revealed no significant differences among the treatments.
This indicates that opening hermetic storage containers has no significant effect on the gaseous
composition inside the containers.
