Indole butyric acid as a pre-sprouting agent for growth and tuberization in Dioscorea rotundata

Abstract

Small tubers of Dioscorea rotundata Poir. (cultivar 'Obiaoturugo') in storage were pre-sprouted for four weeks after treatment with 0-750 mg-1 indole butyric acid (IBA), and then planted in the field. IBA stimulated sprouting by inducing profuse root formation, followed by emergence of sprouts which became significantly (P = 0.05) longer than those formed on the untreated tubers (control) by the fourth week of pre-sprouting in the greenhouse. Optimum concentration of IBA for sprout formation was 500 mg-1 giving 100% sprouting within three weeks. During field growth, dry weight determinations showed that IBA treatment brought about a rapid reduction of the mother tuber, resulting in earlier establishment of an autotrophic plant with higher dry weights of leaf, vine (stem) and root, earlier initiation of the new tuber, and higher yield at harvest.