Yield components have influence on ultimate yield both directly and indirectly. Splitting of total correlation into direct and indirect effects, therefore, would provide a more meaningful interpretation of such association. An experiment was conducted to study the genotypic correlation and character contributions of some physiological traits (stomatal conductance, canopy temperature, leaf temperature and chlorophyll content) to yield in maize. Genotypes used were Sammaz 14, Sammaz 29, 2009

more »

... 2009 TZE-W, TZE COMP-5 and 2009 TZEE,laid out in a randomized complete block design with three replications. Genotypic and phenotypic correlations were estimated. Path analysis was used to determine the direct and indirect effects of the physiological traits on grain yield. The results obtained revealed no significant difference between the genotypes for yield and physiological traits observed. However, the genotype showed good responses to the physiological traits and these can be manipulated to develop drought tolerant genotypes. Heritability, phenotypic and genotypic coefficient of variation was observed to be low. These can be attributed to high environmental variance than genotypic and phenotypic variance. However, stomatal conductance had heritability of 30%. Canopy temperature had a negative direct effect on yield. But the indirect effects were low. Leaf temperature had an indirect effect on yield through canopy temperature. The direct effect of stomatal conductance was high and positive. Stomatal conductance had a positive genotypic and phenotypic correlation with grain yield whilecanopy temperature had a negative genotypic and phenotypic correlation with grain yield.