Effect of Modified Atmospheric Conditions of Hermetically Sealed Large Capacity Cocoons for Storage of Maize Seeds (Zea mays)

Abstract

Studies conducted in Sri Lanka have shown that significant amount of maize is lost during post-production operations due to improper post harvest techniques. Hermetically sealed modified atmospheric cocoon storage is one of the advanced grain storage methods for commercial level storage. This research is focused on the effect of modified atmospheric conditions of sealed cocoons for physical properties and quality conditions of maize seed under local climatic conditions. Initial values of thousand kernel weight, bulk density, hardness, colour, immature seed %, damaged seed % and impurities %, of maize seed were compared with those values obtain after 8 months storage in two methods i.e. large capacity (1100 kg) hermetic cocoon and conventional warehouse storage. Oxygen level inside the hermetically sealed cocoon took 2 weeks to reduce 20.5 to 0.4% . Temperature fluctuation inside the hermetic cocoon was very low in comparison with warehouse. Hermetically sealed cocoon maize seed sample reported similar values as its initial values in term s impurities %, and damaged seed % after 8 months storages, however they were changed significantly in warehouse sample. Change of thousand kernel weight/mass maize seed during storage period was significantly low in cocoon sample. Bulk density and paddy kernel hardness values were significantly reduced in both storage methods from its initial values. Finally, it can be concluded that hermetically sealed cocoon storage has more advantages to preserve seed quality characteristics in comparison to conventional warehouse storage for large capacity commercial storage. However, hermetically sealed condition must be maintained throughout storage period to gain these advantages.