Seed yam production by minisett technique: evaluation of three Dioscorea species in the Guinea and derived Savanna zone of Nigeria

Abstract

Field trials were carried out in Makurdi, Benue State, Nigeria, situated in the Guinea and derived savanna zone, on one local variety each of Dioscorea rotundata Poir. (cv. Dan Onitcha), D. alata L. (cv. Obuna) and D. cayenensis Lam. (cv. Oku) to evaluate their suitability for use as minisetts for rapid seed yam production. For each species, minisetts weighing 20, 25, 30, 35 and 40 g were each cut from the head, middle and tail regions of mother tubers. Setts were treated with Aldrex T, cured overnight and planted directly at a 25 cm × 1 m spacing on ridges. For the head, middle and tail portions at the specified weights of the minisetts, emergence percentages were consistently higher in D. alata than in either D. rotundata and D. cayenensis. Days to 50% establishment were shortest in D. alata and longest in D. cayenensis. Heavier tubers at harvest were obtained from D. alata (285-630 g) than from D. rotundata (105-450 g) and D. cayenensis (40-230 g). The potential value of the use of the minisett technique appeared more promising for D. alata and D. rotundata than for D. cayenensis.