Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4517181 | Journal of Stored Products Research | 2012 | 8 Pages |
This study reports the efficacy of using CO2 against Sitophilus zeamais and Sitophilus oryzae as an alternative treatment to fumigation for rice stored in a rice mill in Portugal. The trials were conducted in a silo containing 40 tonnes of polished rice and in four hermetic big bags of 1 tonne capacity; two with paddy and two with polished rice. The composition of the atmosphere ranged from 90 to 95% CO2 and 0.7–2.1% O2. Three trials were carried out at different temperatures and treatment times; stored rice in the silo at 29.6 ± 0.1 °C for 26 days (first trial), at 34.1 ± 0.2 °C for 10 days (second trial), and in big bags at 22 °C for 26 days (third trial).To evaluate the efficacy of each treatment, metal cages with 16 g of infested rice where placed at bottom, middle, top and surface of the polished rice in the silo. Four replications of each type of infested rice containing one-week-old S. zeamais adults, or eggs of S. zeamais or S. oryzae, were incubated in the laboratory, at the same temperature as in the silo, to serve as a control.In all modified atmosphere treatments adults of S. zeamais, and eggs of both S. oryzae and S. zeamais, showed mortality close to 100% and no F1 emergence was recorded in any treatment sample. This was the first time that a Portuguese rice mill used modified atmospheres.
► Trials were carried out using CO2 in stored rice: in a silo at 31 °–32.7 °C for 26–10 days, respectively, and big bags at 22 °C for 26 days. ► The treatments suppressed all stages of Sitophilus spp., the time of gas exposure depending on grain temperature. ► No difference on sensory qualities of cooked rice, between treated and non-treated polished rice. ► The results confirmed the use of CO2 is an efficient alternative method to Fumigation to control stored rice pests.