The Evaluation of Pyrethrum Flowers (Chrysanthemum Cinerariaefolium)

Abstract

1. The analytical methods of Tattersfield, Hobson and Gimingham(6) and Gnadinger and Corl(1) for the determination of the pyrethrins in pyrethrum flowers are compared, and certain modifications in technique suggested.2. Good concordances have been obtained between analytical data and insecticidal tests employingAphis rumicis.3. A new method for the rapid and approximate evaluation of unadulterated samples, employing small quantities of material, is described.4. Observations on the pyrethrin content of individual flowers in the various stages of development are recorded, making use of a modification of the method indicated under (3).