Comparative Study on Growth and Yield Response of Hybrid and Local Cultivars of White Yam (Dioscorea rotundata Poir.) in Edo State Nigeria

Abstract

The growth and yield response of three hybrid yams (TDr 89/02665, TDr 89/02565 and TDr 89/02677) and fifteen
local white yam cultivars were evaluated in the rainforest ecology of Edo State Nigeria. The experiment was carried out in order to
document the performance of the three hybrid yam in comparison with local white yam cultivars. The three hybrid and fifteen local
white yam cultivars were grown in the Teaching and Research Farm of the Faculty of Agriculture, University of Benin, Benin City,
Edo State, Nigeria during the 2009 planting season using a 6m single row plot per cultivar at a spacing of 1 x 1m. The experiment was
laid out in a randomized complete block design with three replications. All the yam cultivars were sown in mounds using whole seed
yam weighing about 0.5kg. Each cultivar was manually weeded, and NPK (15:15:15) was applied at the rate of 400kg/ha at 8 week
after planting. The results showed that there was significant difference among all the white yam cultivars in the number of leaves,
length of tenth internode, spininess (P ≤ 0.05). There was no significant difference in fresh tuber yield among all yam cultivars.
However, the fresh tuber yield of hybrid and local yam cultivars ranged from 14.6 – 19.2 t/ha and 8.7 – 33.7t/ha respectively. Among
the hybrid cultivars, TDr 89/02677 had the greatest fresh tuber yield and was followed by TDr 89/02665 and TDr 89/02565. The fresh
tuber yields of Abakaliki, Ikale, Alumako, EKpen, Oboko, Asoko, and Iyawo 1 were all greater than TDr 89/02677 (the most
promising hybrid yam cultivar). Also, most of the local white yam cultivars exceeded the three hybrids in tuber dry weight. The
superior performance of some of the local white yam cultivars indicated that farmers’ clonal selection at farm level is an obvious
reality. However, the high yield potential of the three hybrid cultivars has been confirmed from this study, and the farmers can adopt
them in order to boost the genetic diversity of their planting material. Moreover, the hybrid yam cultivars are known to show tolerance
to low soil nutrient status when planted early. A participatory on-farm trial of the hybrid and local cultivars is hereby recommended to
speed up adoption of the hybrid varieties.