Evaluation of exotic genotypes of Taro (Colocasia esculenta) in Nigeria

Production of Taro {Colocasia esculenta (L) Schott} in Nigeria had stagnated and even began to decline in the last few years due to several constraints including poor yield of local cultivars worsened by advent of taro leaf blight (TLB). Introduction and evaluation of exotic cultivars for adaptation to local production is a promising option to increase local variability, diversity and yield of taro. The objective of this experiment was to evaluate newly introduced (exotic) cultivars of Taro in order to identify and select those with high yield, TLB resistance and quality suitable for local production. Fifteen exotic cultivars of taro, obtained  from International Network on Edible Aroids (INEA) as part of an EU-funded project on \Adapting Clonally  Propagated Crops to Climatic and Commercial Change,. and some local cultivar were evaluated in 2013  and 2014 at Umudike, located between latitudes 5‹24. to 5‹30. N and longitudes 7‹31. to 7‹37. E in the  rainforest agro-ecological zone of Nigeria. The cultivars were laid out in a randomized complete block  design in two replications. Results obtained indicate that most of the exotic cultivars were early   maturing, four were intermediate while two (BL/SM/152, and BL/PNG/13) were late maturing. Most   cultivars were susceptible to TLB; BL/PNG/13 was highly resistant while BL/SM/152 was immune. The  late maturing cultivars were highly resistant/immune to TLB while most of the early maturing ones were  susceptible thus suggesting a link between the genes for maturity and those for resistance to TLB.  Cultivar differences in number of corms, cormels and total yield (corms + cormels) per plant were  significant in both years. Total yield and Corm/Cormels ratio of many exotic cultivars compared   favourably with the locals. Nine cultivars were selected as promising based mainly on yield, physical  appearance, resistance to TLB and lack of stolon.Keywords: Cocoyam, cultivars, corm/cormel ratio, taro leaf blight, maturity, total yield, cormsand cormels