A half diallel cross (excluding reciprocals) was made using eight yellow maize inbred lines developed at Gemmeiza and Giza
Agricultural Research Station. The 28 F1 single crosses along with two commercial hybrids (SC 162 and SC 168) as check hybrids
were evaluated during 2014 summer season in two different field experiments at two locations; Gemmeiza and Nubaria Agric. Res.
Stn. A randomized complete blocks design (RCBD) with four replications was used. Diallel analysis of Griffing's Method-4, Model
1 was used to estimate combining ability. Highly significant GCA and SCA mean squares were recorded for all studied traits. Results
revealed the preponderance of additive gene effects for all studied traits. In general, all the evaluated F1 single crosses were significantly
earlier than the earliest check hybrid SC 168. The most superior parental inbred line for earliness, shortness and low ear
placement was Gm 6044. The best combiners for high grain yield, ear length and ear diameter were inbred lines Gz 658 and Gm
6052. The best F1 crosses for grain yield which outyielded the highest check hybrid SC 168 were Gm 6022 x Gz 658, Gm 6052 x
Gm 6022, Gm 6061 x Gm 6052 and Gm 6061 x Gz 658.These hybrids appeared to be promising and should be further tested for
release as new yellow single cross hybrids for commercial use.