Efforts Towards the Development of High Yielding and Stem Borer Resistant Maize in a Humid Environment

Field experiments were conducted at the Teaching and Research Farm of the Department of Crop Science, Faculty of Agriculture, University of Nigeria, Nsukka to commence the process of developing high yielding maize with resistance to stem borers in a humid environment. The specific objectives were to (i) screen some maize genotypes for agronomic traits and stem borer resistance (ii) estimate some genetic parameters of the genotypes studied. Twenty maize genotypes used comprised twelve maize genotypes collected from the International Institute of Tropical Agriculture (IITA) namely (2009 TZE OR1 DT STR QPM (TOR1), AMA TZBR – Y – F2 (AMA), TZBR COMP – 2 – YC1F2 (COMP2), BR 9928 DMRSR (B28), DMR – LSR – Y (DMR), TZE – Y – POP DT STR QPM (POP), 2009 TZE OR2 DT STR QPM (TOR2), 99 TZE Y – STR QPM (99 TZE), BR 9943 DMRSR (B43), TZBR COMP – YC1F2 (COMP1), EV DT – Y – 2000 STR QPM (EVDT) and TZEE – Y -POR STR QPM CO (PORC)) and eight (8) local accessions (Ugwuachara (UG), Umukasi (UM), ORBA1, Obukpa (OB), ORBA2, Edem Ani (EA), Isakpu (IS) and Ajuona (AJ)) from Enugu state, Nigeria. The parameters measured include days to tasselling, silking, maturity, stem girth, number of leaves, ear height, plant height, ear length, ear diameter, number of kernel per row, number of rows per ear, number of kernel per cob, number of ear per plant, shelling percentage, ear weight, grain yield, brown spot disease, lodging incidence, stem borer infestation, number of exit holes and tunnel damage length. General combining ability (GCA) of the parents and specific combining ability (SCA) of the hybrids were estimated using Graffings’ model 1 method 2 in a 10 x 10 diallel cross. Among the parents, POP and PORC had significantly (p