he promising cotton line CB 58 x Giza 90 was grown compared with
Giza 90 and Giza 95 cultivars and a new promising line at four
locations during 2016 and 2017 seasons (eight environments) in
South Egypt. The randomized complete block design with four replications
was used at each location. The characters studied were seed cotton yield,
lint yield, boll weight, lint percentage, seed index, lint index, fiber length,
length uniformity ratio, micronaire reading and fiber strength. Significant
differences were detected among genotypes for all traits except boll
weight. In addition, significant differences were found among
environments for all characters. Genotype by environment interaction was
significant for all studied characters except boll weight, seed index and lint
index. The promising line CB 58 x Giza 90 surpassed the commercial
cultivars for yield traits but, it did not differ significantly with the promising
line [((G.83 x G.80) x G.89) × Australian] for lint percentage. The
promising cotton line CB 58 x Giza 90 was equal to the commercial
cultivars for length uniformity ratio. The commercial cultivars recorded the
highest values for seed and lint index. Giza 95 cultivar recorded the best
values for fiber characters. The promising line CB 58 x Giza 90 produced
the highest values for most characters at sohag location where it
surpassed the commercial cultivars for yield characters and with no
significant difference for fiber length. Therefore, it seems necessary to
continue evaluating the new cotton genotypes at several locations over an
adequate number of years before recommending a given variety for a
certain location. Giza 90 cultivar was considered stable across a wide
range of environments. Giza 95 cultivar was less sensitive to
environmental changes. So it could be more adapted to poor- yielding
environments. The genotypes, Giza 90 and the two lines had more general
adaptability to all environments.