Submitted to: International Controlled Atmosphere Research Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/1/2008
Publication Date: 9/16/2008
Citation: Flinn, P.W., Reed, C. 2008. Effects of Outside Air Temperature on Movement of Phosphine Gas in Concrete Elevator Bins. In: G. Daolin, S. Navarro, Y. Jian, T. Cheng, J. Zuxun, L. Yue, L. Yang, and W. Haipeng (Eds.), Proceedings of the International Conference on Controlled Atmosphere and Fumigation in Stored Products, Chengdu, China, September 21-26, 2008. Sichuan Publishing Group, Sichuan, China. PP. 704-706.
Technical Abstract: Studies that measured the movement and concentration of phosphine gas in upright concrete bins over time indicated that fumigant movement was dictated by air currents, which in turn, were a function of the difference between the average grain temperature and the average outside air temperature during the two weeks following application of the aluminum phosphide pellets. When the grain was warmer than the average outside air temperature during these two weeks, the phosphine gas would move upward through the grain mass. When the grain was cooler than the average outside air during these two weeks, the fumigant moved downward. Because insect problems normally occur in the top of the grain mass early in the storage season (June-August), a uniform application of fumigant pellets was more effective when the grain and outside air temperatures were similar during the two weeks following application of the fumigant. When grain was much warmer than the average outside air temperature during these two weeks, applying more fumigant pellets into the bottom half of the grain mass was the most effective strategy. If the grain temperature is expected to be cooler than the average outside air temperature during the two weeks following applicatin of the fumigant, applying more pellets to the upper half of the grain mass would be the best strategy.