Published online by Cambridge University Press: 27 March 2009
When pre-harvest foliar applications of growth regulators were made to vines of Dioscorea esculenta cv. Chinese Yam and D. alata cv. White Lisbon there were no obvious effects on tubers of D. alata, but dramatic effects on tuber development, storage and germination were obtained with D. esculenta tubers. Gibberellic acid caused marked extensions in tuber dormancy, 2,4-dichlorophenoxyacetic acid resulted in marked callus development, delayed germination and abnormal shoot and root development and indole acetic acid resulted in fingering of the tubers. It was concluded that there was potential for commercial exploitation of pre-harvest gibberellic acid treatments in extension of dormancy in Chinese Yam tubers and that the lack of response of D. alata tubers to foliar application of growth regulators warranted further investigation.