Effect of vitamins on sprouting of purple nutsedge tubers.

Vitamins of the B group and vitamin C were applied to purple nutsedge (Cyperus rotundus L.) tubers to study their effect on the sprouting rate, initiation and establishment of sprouts, growth of plantlets and development of orthotropic rhizomes in comparison with the corresponding effects of kinetin. Ascorbic acid up to 100 mg l-1 hastened sprouting, whereas vitamins of the B group and kinetin retarded sprouting: 100% tubers sprouted in all treatments within 10 days. Unlike kinetin, none of the vitamins resulted in the establishment of more than one sprout per tuber. Riboflavin and pyridoxine promoted root and shoot growth of the plantlets, whereas kinetin produced short, thick shoots and inhibited root growth, with increasing concentration. Ascorbic acid was only second to kinetin in the induction of orthotropic rhizomes, but the former resulted in an increase in rhizome length.