The growth-retarding effect of Alden in Spirodela oligorrhiza

Summary Alden® (10^–5 M) retarded growth and increased chlorophyll and protein contents in Spirodela, the effects being reduced by gibberellin and benzyladenine. Alden nearly doubled activity of soluble phosphatase and increased activity of RNase.Acknowledgments. Original inoculum of S. oligorrhiza was kindly supplied by Prof. E. G. Bollard and Dr. A. R. Ferguson of the Plant Diseases Division, D. S. I. R., Auckland, New Zealand. Alden® was kindly supplied by Dr. W. H. De Silva of Dr R. Maag Ltd., Chemical Works, Dielsdorf, Switzerland.