Yield and Post-Harvest Pest Status of Some White Yam (Dioscorea rotundata Poir.) Landraces in Uyo Southeastern Nigeria

Abstract

Field experiment was conducted at National Cereals Research Institute (NCRI),Uyo out- Station in 2012 and 2013 to evaluated yield and post-harvest pest status of some yam landraces in Nigeria. The experiment was laid out in a randomized complete block design (RCBD), replicated thrice. Treatments were eight white yam landraces; Nwopoko, Obiotorugo, Offala, Hambakwashe, Aloshi, Udeanyi, Pepa and Eteme and one improved yam cultivar TDr 89/02665. Data obtained from yield and pest severity were subjected to analysis of variance. Result showed that Hambakwase produced significant tuber yield of 31.10 and 33.01 t/ha in 2012 and 2013, respectively. Obioturugo produced 28.18 and 28.02 t/ha, respectively. Eteme produced the least tuber yield of 16.23 and 15.33 t/ha. Udanyi had significant higher number of rotten tubers per plot at harvest; 2.41 and 2.08 in both years. At 3 months in storage, Offala had significant dry rot of 1.73 and 2.01, followed by 1.61 and 0.91 dry rot tubers per plot, recorded in Aloshi. Number of wet rot tubers per plot as influenced by white yam landraces at 3 months storage varied significantly different (p<0.05). Udanyi had significant higher number of wet tuber rot; 4.30 and 3.22 in 2012 and 2013. Presence of mealy bug infestation were seen Offala, Aloshi,Udanyi and Eteme in 2012. In 2013, Offala, Udanyi, Eteme and TDr 89/02665 had mealy bug infestation. .Among the yam landraces, scale insects were observed in the following; Obioturugo, Hambakwase and Udanyi in 2012 while in 2013, Obioturugo, Udanyi and Eteme had presence of scale insect in tubers at 3 months storage. This study therefore recommended Hambakwase and Nwopok for high tuber yield, less susceptible to rot, beetle and termite attack. Also, these promising yam landraces showed be incorporated into yam breeding programme in Nigeria.