Abstract

Enormous quantity of table-size yams that are capable of guaranteeing national food security are used as seeds in yam cultivation annually, which negatively impact yam availability for consumption. Hence, there is need for effective production of yam minisett, in order to reduce the dependence on wareyams for seeds, towards sustainable yam production necessary for food security. Therefore, field trials were carried out at two contrasting ecological zones during 2019 planting season at Teaching and Research Farm, Malete and Olla, both in Kwara State, Nigeria. The aim of the study was to evaluate the vegetative growth and tuber yield of white yam cultivars (Dioscorea rotundata Poir) as influenced by minisett size. Three commonly grown white yam cultivar [O dara bi iyawo (ODA), Aamula (AMA), Omi-efun (OMF)] and four minisett sizes (50, 100, 150 and 200 g) of each cultivar were factorially combined in a randomized complete block design (RCBD) using split-plot arrangement replicated three times. Significant variations were observed among the yam sett sizes and cultivars. Tuber yield also varied significantly with ODA>AMA>OMF regardless of location. The sizes of harvested minisett tubers increased in descending order (200>150>100>50). Although leaf production rate, vine length, leaf area index, and number of leaves per plant were poor for the 50 and 100 g minisett sizes, but tuber multiplication rate and tuber weight were higher in these minisett sizes than the other sizes. Particularly for cultivars ODA and AMA, the multiplication rate of 50 g size minisett was significantly higher than for the larger size minisetts. Based on the results obtained in this study, 50 - 100 g, 100 g, and 100 - 150 g minisett sizes for ODA, AMA and OMF, respectively, is found suitable for minisett production. In fact, further increase from 150 to 200 g minisett for the evaluated cultivars will produce wareyam above desired seed-yam size for commercial production.