Abstract
Field studies on the growth pattern of the white guinea yam, Dioscorea rotundata Poir., propagated by seed, were carried out from May through November 1979 and 1980, using the method of growth analysis. Active growth of roots, stem and leaves occurred simultaneously within the first eight weeks following transplanting. Consequently, the competition of these organs for available photosynthates led to final dry weights lower than those usually observed in tuber-propagated D. rotundata, where active growth of these organs is known to occur sequentially. Although tuber initiation occurred after only two weeks of transplanting, substantial tuber growth was delayed until the completion of canopy growth, about the eighth week. The plants maintained a relatively high mean relative growth rate of 0.301 gg-1 wk-1 and leaf area ratio of 113 cm-2 g-1 but a low mean net assimilation rate of 27 g m2 wk-1. The results suggest that increased final yield could be achieved by shortening the time before onset of active tuber bulking, lengthening the duration of tuber bulking and increasing canopy growth. The results are discussed in relation to the growth pattern and growth rates of D. rotundata plants vegetatively propagated.
