Experiments on diffusion of phosphine in cut flower boxes.
Karunaratne, C., Moore, G. A., Thorpe, G. R., Jones, R. and Ryan, R.
Acta Horticulturae Year: 1998 Issue: No. 464 Pages: 297-302.
1998
บทคัดย่อ
The change in concentration of phosphine over time in different locations of a half-sized fibreboard flowerbox was measured in order to ascertain the efficacy of phosphine as a fumigant for cut flowers under commercial situations. Samples taken from various locations in the box were analysed for phosphine using gas chromatography, and the time - concentration relationship of phosphine diffusion in a box with or without flowers in still or moving air was determined. Diffusion of phosphine into flower heads of protea was also measured. In an empty flower box, phosphine took 240 min to attain equilibrium in still air compared with 800 min predicted if mass transfer were governed by pure diffusion. Equilibrium was reached in an empty box in 35 min; in a box packed with flowers it took 60 min, whilst diffusion into a protea flower head took 75 min with some bulk movement. The results highlighted that a box full of proteas cause resistivity to the free movement of phosphine and that the time required
to attain equilibrium (130 min) inside a flower head can be as much as 50% of a standard fumigation time of 4 h.