EVALUATION OF MAIZE S2 LINES FOR YIELD ATTRIBUTES IN TESTCROSS COMBINATIONS

A research trial was planned to evaluate maize S2 lines for yield attributes in testcross combinations. Twentyseven S2 lines were each crossed to two testers at Research Farm of The University of Agriculture, Peshawar, Pakistan, during spring crop season 2008. After discarding 18 testcrosses at harvest for no or low seed setting, the remaining 36 testcrosses along with two testers and 18 parents were evaluated using lattice design with three replications at New Developmental Farm of The University of Agriculture Peshawar, during summer crop season 2008. The results revealed that the testcrosses differed significantly (P 0.05) among testcrosses were observed for ear length, 100-grain weight and grain yield. Highest grain yield (6106.9 kg ha -1 ) was recorded for testcross SW-17 x Jalal. Maximum 100-grain weight (34.7 g) was observed for SW-16 x Jalal. Maximum ear length (17.6 cm) was recorded for SW-3 x Jalal. The highest number of grain rows ear -1 (16.3) was observed for SW-17 x WD-2x8 while lines SW-14 and SW-24 were the best general combiners for grain yield. Lines SW-9 and SW-24 proved to be good general combiners for 100-grain weight. Lines SW-5 and SW-17 were good general combiners for grain rows ear -1 while lines SW-3 and SW-24 were good general combiners for ear length. WD-2x8 showed good GCA against grain rows ear -1 and ear length while Jalal showed good GCA for 100-grain weight and grain yield. Line SW-24 can be used to improve more than one trait simultaneously. SW-24 was a good general combiner for grain yield, 100-grain weight and ear length. SW-17 x Jalal and SW-3 x Jalal were good specific combiners for grain yield. SW-16 x Jalal, SW-6 x Jalal, SW-22 x WD-2x8 and SW-27 x WD-2x8 were good specific combiners for 100-grain weight. SW-11 x Jalal was a good specific combiner for grain row ear -1 . A good specific combiner for ear length was SW-3 x Jalal. These testcrosses can be further evaluated while breeding for high yielding varieties and are recommended to be included in subsequent breeding programs for improvement of maize gene pool.