General and specific combining ability studies of yield and yield character of sweet potato weevil in predominant and non-predominant environments

Combining ability for marketable sweet potato root yield were carried out using ten sweet potato varieties and their F1 hybrids in Cylasformicarius endemic (Landmark University, Omu Aran) and free (University of Ibadan) environments during 2012 cropping season. Both general combining ability and specific combining ability play significant role on traits such as marketable root yield, non- marketable root yield, and total number of storage root/plant and marketable storage root, root size, percentage of tuber damage and weight of total roots, as well as the incidence and severity were generally low, suggesting the role of additive and dominant gene action in tolerances to Cylasformicarius. Hybrids from the parents Resisto, TIS 87/0087 displayed high performance in term of Cylasformicarius tolerance. These parents and their hybrids appeared to have gene pools for Cylasformicarius tolerance that can be manipulated for developing promising hybrids in South west, Nigeria.