Evaluation of Some Inbred Lines of Maize in a Diallel Cross Under Two Sowing Dates

Abstract

A half diallel set of crosses were made among seven inbred lines of white maize during 2021 growing season to estimate combining ability for days to 50% tasseling, days to 50% silking, plant height, ear height, ear leaf area, chlorophyll content, number of rows per ear, number of kernels per row, ear length, ear diameter, 100-kernels weight and grain yield per plant under two sowing dates (14th of May “recommended date” and 14th of June “late sowing date”) in two separate field experiments. Each experiment included 21 F1 hybrids and the check variety SC 128 in a randomized complete block design with three replications during 2022 season. Results indicated that mean squares due to genotypes, sowing dates and the interactions between them were significant / or highly significant for all the studied traits. Mean squares due to GCA, SCA and their interactions with sowing dates were highly significant for all the studied traits. The ratios of GCA/SCA variances were less than the unity for all the studied traits indicating that the non-additive genetic effects had the main role of the expression of these traits. The parental inbred lines P3, P4 and P7 seemed to be good general combiners for grain yield and most studied traits under the two sowing dates. The crosses P1xP4, P2xP6, P3xP5, P3xP7 and P6xP7 were the best cross-combinations for grain yield and most of the studied traits under two sowing dates.