ASSESSMENT OF F1 PROGENIES OF SWEETPOTATO (Ipomoea batatas (L.) Lam) FOR YIELD AND SUSCEPTIBILITY TO SWEETPOTATO WEEVIL (Cylas puncticollis) UNDER RAINFED CONDITION IN UMUDIKE, NIGERIA

Abstract

Poor storage root yield and incidence of sweetpotato weevil Cylas puncticollis constitute major constraints to sweetpotato production in Nigeria. The objective of this study was to assess newly developed progenies of sweetpotato and identify promising genotypes with high storage root yield and resistance to Cylas spp. For this purpose, a field experiment was conducted at the National Root Crops Research Institute, Umudike, Southeast Nigeria during the 2015 and 2016 cropping seasons to evaluate diversity across progenies of different sweetpotato families, namely: SautiX442162 (6), SautiXLigri (5) and Sauti Poly Cross (10), including two national check varieties (Umuspo 3 and TIS 87/0087). This experiment was laid out in a randomized complete block design with three replicates. In this study, progenies of sweetpotato exhibited morphological variability storage root characters. SautiXLigri/4 (13.33t/ha) and SautiX442162/1 (12.70 t/ha) produced higher fresh storage root yield than the national check (Umuspo3) while five genotypes; SautiXLigri/4 (13.33t/ha), SautiX442162/1 (12.70 t/ha), SautiX442162/5 (12.03 t/ha), SautiX442162/2 (11.04t/ha) and Sauti PC/9 (9.97t/ha) produced higher fresh storage root yield than the national check (TIS 87/0087). Among the twenty one genotypes evaluated, nine genotypes; SautiX442162/5, SautiX442162/3, SautiX442162/2, SautiXLigri/2, Sauti PC/4, Sauti x 442162/1, Sauti PC/1, Sauti PC/5, Sauti x 442162/6 were susceptible to the attack of C. puncticollis. Sautix442162/5 had the highest attack of C. puncticollis, followed by Sautix442162/3 and Sautix442162/2 while twelve genotypes; Sauti PC/2, Sauti PC/3, Sauti PC/6, Sauti PC/7, Sauti PC/8, Sauti PC/9, Sauti PC/10, SautiX442162/4, SautiXLigri/1, SautiXLigri/3, SautiXLigri/4, SautiXLigri/5 did not record attack of C. puncticollis. This suggests that these genotypes may possess resistance genes and could be incorporated in breeding programs to produce hybrid varieties that are high yielding and resistance to Cylas puncticollis.