Pyrethrum Drying

Abstract

When first the subject of the artificial drying of pyrethrum was raised, the only information available was to the effect that drying at a temperature of 40º C. (104ºF.) caused no loss of pyrethrins. Accordingly, it was recommended that drying houses should be run at temperatures between 100 and 105 0 F. For weather, produced very dingy flowers various reasons, discussed below, drying was very slow, and soon higher temperatures were being employed. Drying houses run at over 150º F. have been It is strongly recommended that the visited.