Potentiality of Some Egyptan Cotton Varieties under Drought Stress Conditions

This study aimed to investigate the performance of three cotton (Gossypium barbadense L.) genotypes as affected by drought stress at three irrigation regimes; 14 (S-0), 21(S-1) and 28 (S-2) days that were started after the first irrigation. To achieve this goal, a field experiment was conducted as split block design at the Experimental Farm of the Faculty of Agriculture, El-Fayoum Univ. The results indicated that the irrigation regimes mean squares of combined data were highly significant for earliness traits, also as well as yield and yield components. Most of fiber properties were not affected by water stress conditions. Significant differences were found among the non- stress (S-0) and the stress treatments (S-1 and S-2) for mean performances of the three earliness traits. Treatment S-2 led to significant decrease in yield and yield components compared to S-0. The results showed that Giza 85 variety gave the highest fiber length, fiber strength and was finer cultivars having the lower micronaire values. The interaction between genotypes and stress treatments was significant for most traits.G1,G2 and G3 cotton varieties exhibited highest seed cotton yield kg ha-1 (yield potential) in the non- stress treatment (S-0). Giza 90 variety outyielded the other two varieties under stress treatment (S-2) compared to those of Giza 85 and Giza 83. The superiority of Giza 90 variety could be attributed to its high yield components., while Giza 90 was relatively stress susceptible and similar trend of those obtained using data of relative productivity (%) which confirm that the genotype Giza 83 and Giza 85 are more drought tolerance and could be used as sources of drought stress tolerance in breeding programs and tolerance to water stress conditions.