The effectiveness of honeycomb pedigree selection (HPS) as compared to conventional pedigree selection (CPS) and mass selection (MS) were studied in one interaspecific cross between two promising hybrids Giza84 × (Giza74 × Giza 68) and Giza 77 × Pima S6. Combined selection for yield and lint quality traits was applied for three cycles. Finally, the best F5 lines derived by each method were tested in comparative experiments as randomized complete blocks design with three replications at Sakha Agric. Res. Station (2010). The analysis of variance indicated significant differences among of the selected lines for seed cotton yield and other traits except, for mean of boll weight. No significant differences were found between overall means of two groups CPS and HPS. In contrast, the mean of lines derived from third method MS. No significant differences however, were identified between the selected lines of the two methods (HPS and CPS) for lint quality traits. On the basis of mean seed cotton yield, boll weight, lint percent and fiber length as well as number of superior lines derived by each method. It was concluded that HPS was effective than CPS and MS in identifying lines with high yielding ability and a good lint quality. This superiority of HPS is attributed at least partially to its effectiveness in early segregating generation selection.

Plant breeder use yield traits to identify promising genotypes. This goal depends the magnitudes of genotype by environments and stability performance of genotypes. Therefore, twenty Egyptian extra long genotypes were grown in three locations under two years for yield, yield components earliness and fiber traits to identify promising stability genotypes. The genotype x environment interaction was significant for yield and fiber traits. It also noticed that variation due genotype x environment were further partitioned into linear and non-linear components. Genotype x environment linear was insignificant for all studied traits except for MC trait, insignificant of genotype x environment linear indicated that genotypes didn't differ genetically in their response to different environments. Pooled deviation mean squares were significant for all studied traits , indicated that the major components for differences in stability were due to deviation from the linear function. Therefore, it could be concluded that the relatively unpredictable components of the interaction maybe more important than the predictable components.The results illustrated that lines 3, 5 and 15 were stable for seed cotton yield (x -