Performance of Improved Sweet Potato (Ipomea batatas L.) Varieties in Makurdi, Southern Guinea Savanna of Nigeria

Aim: To investigate the performance of some improved sweet potato varieties obtained from the National Root Crops Research Institute (NRCRI), Umudike, Nigeria, for root yield and other yield components.
Study Design: Field experiment.
Place and Duration of Study: Teaching and Research Farm of the Federal University of Agriculture, Makurdi in Benue State, located in the Southern Guinea Savanna of Nigeria from June-November of 2010 and 2011.
Materials and Methods: The treatments comprised of eleven sweet potato varieties [CIP 440141, K134, NASPOT4, NASPOT2, SPK004, TIS87/0087(check), CIP440037, 1900411, NARSP/05/007C, CIP440293 (orange skin and flesh) and NARSP/05/022 (orange flesh)] set out in randomized complete block design with three replications. Ten farmers were used for the preference test of the varieties.
Results: Some vegetative growth parameters evaluated in the study (number of branches/plant, internodes length, number of leaves per plant and vine length) increased at different rates between 4 - 16 weeks after planting. Root diameter and length, number of saleable roots and weight varied with the varieties of sweet potato in Makurdi. NARSP/05/022 gave the highest number of leaves, number of roots (121817/ha) and weight (54151 kg/ha) at harvest, although it also had the highest incidence of sweet potato weevil infestation. This variety was the only one that had significantly higher saleable root weight than the check (TIS 87/0087). Saleable root weight correlated positively and significantly with number of saleable roots and root diameter.
Conclusion: Farmers will likely consider NARSP/05/022 for adoption despite the high weevil infestation. For reasons other than root yield (taste and colour), farmers may adopt CIP440293.