Estimation of the variance of some Egyptian cotton genotypes in the delta and upper egypt using different approaches of combined analysis [electronic resource].

Includes reference.

The present investigation is dealing with the variances of two groups of long staple Egyptian cotton (Gossypium barbadense L.) genotypes, with respect to yield, its components and fiber properties in the Delta and the valley during 2004 and 2005 seasons. The first group, viz. G.8S, G.86, G.89 and G.89 x G.86 were evaluated in the Delta (Monofia and Gharbia). The second group, viz. G.80, G.83, G.90 and G.91 were evaluated in the valley (Assuit and Beni Souf). Randomized complete block design was used in each experiment. The final goal was to study the possibility of suggesting a modified analysis of randomized complete block design to replace the use of traditional combined analysis. In such proposal the data of the two groups of genotypes were used together. Two main locations were formed. The first, i.e. Delta locations included the data of Monofia and Gharbia Governorates. Gathering data of Assuit and Beni Souf formed the second one, i.e. valley. Thus, each main location (Delta or Valley) included the same number of replicates as in any Governorate due to each plot contained two readings (k) one for each Governorate. Genotypes (g) partitioning into two groups, viz. genotypes Delta (gd) and genotypes valley (gv). Modified surpassed combined due to it does not need to calculate homogeneity test of variances (Bartlett test) before the start of analysis. Modified analysis could estimate two groups of genotypes variance on one stage of analysis, while combined analysis could estimate the same results using two stages of analysis. Results exhibited modified made two directions of the analysis different both groups and locations, while combined made one direction of the analysis one group in different location. Modified could be calculated (gd) vs (gv) variance, while combined could not calculate. Although the two ways of analyses calculated the same value of variance for each group of genotypes but they exhibited different results of significant variation due to different values of F Table of them, which depend un the degree of freedom of the error.

Summary in arabic.

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