Phenotypic,genotypic and environmental correlations of quantitative characters in winter wheat

In the experiment with 18 winter varieties the genotypic, phenotypic and environmental correlations were estimated in all combinations between the pairs of 11 quantitative characters. Both yield of grain with its components and further characters were evaluated, of which flag leaf size and leaf angle of the last but one leaf are of importance for the utilization of light energy and consequently for receiving maximum rates of photosynthesis. In simple genotypic and phenotypic correlations their different stability with regard to mineral nutrition, eventually to the date of sowing was proved. In the discussion the limited signification of simple correlation for the statement of complicated processes in plants caused by multiplied associations of characters was pointed out. In the example of yield components of the plant at the application of 60 kg N per hectare it was shown that also further unknown variable factors might participate in the genotypic correlation. It may be concluded that the inclusion of them when constructing the selection indexes will give further foundations for handling yield as a breeding or genetic character, and for the causal analysis of yield formation in wheat.