Genetic Parameters and Path Coefficient analysis in Cotton as Affected by Planting Location

Seven varieties of upland cotton (Feard, KC3, H23, Lashata, Coker310, Marsomy, and Ashur) were planted in two different locations (Abu-Ghraib and Al-Musaib) in summer season of 2004 using a randomized complete block design with three replicates to determine the most important characters which can be used as effective selection criteria for improvement yield of seed cotton. Genotypic, phenotypic variances and coefficients of variability, broad sense heritability percentage, co-heritability, genotypic and phenotypic correlation coefficients among yield of seed cotton and other characters were estimated. Path coefficient analysis carried out to partition the genotypic correlation coefficient to the direct and indirect effects. The results showed that genotypic, phenotypic variances and coefficients of variability were varied for all characters studied with difference of planting location, and seed cotton yield appeared large values at two locations. Mean of boll weight appeared large broad sense heritability percentage (60%) in Abu-Ghraib location and earliness character appeared large broad sense heritability percentage (67%) in Al-Musaib location. Higher value of co-heritability coefficient was obtained between seed index and number of boll / plant (3.90) in Abu-Ghraib, and higher value of co-heritability coefficient was obtained between seed cotton yield and ginning outturn (86.26) in Al-Musaib. Seed cotton yield / plant showed highly significant positive genetic correlations with number of bolls / plant (0.991 and 0.792) in Abu-Ghraib location and (0.962 and 0.917) in Al-Musaib location. Results of path coefficient analysis showed that mean of boll weight, number of days to first flower bloom and seed index had the most positive direct effects on seed cotton yield (6.36, 3.91 and 1.01) respectively, and indirect effects through the others, so these characters could be used as a selection criteria in breeding programs of selection to improve seed cotton yield in Iraq.