Abstract

                                The yield of a crop and quality of the agricultural produce for which it is valued are highly complex characters which are governed by a large number of genetic factors. The expression of these characters is also influenced to a great extent by the environment and the appearance and behaviour of a genotype may therefore be taken to represent an interaction between heredity and environment. Chandrasekharan and Parthasarathy (1948) stated that earliness in crops like Cholam and rice is a Mendelian character but it is also governed by an environmental factor like light. Garner and Allard (1920) pointed out that the length of the day and night has pronounced effect on the onset of flowering. Thus, even genetically pure strains of crop plants are known to show developmental or fluctuating variations under the influence of different set of environmental conditions. These fluctuating variations are important to the plant breeders engaged in crop improvement work as they affect the proper evalution of the desired genotype. Therefore, a detailed knowledge regarding the influence of environmental factors on economically important characters of crop plants is very essential.

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