The possibilities of using physiological efficiency of nitrogen in wheat breeding in terms of ecological agriculture

Inadequate amounts of fertilizers, especially nitrogen, have negative effects on ecosystems and food safety. On the other side, fertilizing, with an improvement in cropping systems, mainly in developed countries, has provided a food supply sufficient for both animal and human consumption. Therefore, with the increasing world population, the main task for the following decades is to develop highly productive agriculture, whilst at the same time preserving the quality of the environment. A multidisciplinary approach to winter wheat breeding and the inclusion of physiological indicators of nitrogen nutrition efficiency in this process could be helpful in reaching this goal. This study deals with the physiological efficiency of nitrogen as one of the physiological indicators, its relation with grain yield, heritability and variance and evaluation of Serbian winter wheat genotypes according to this indicator. The highest values of the physiological efficiency of nitrogen were registered at KG 165/2 and Lazarica. These genotypes, selected as superior in terms of this indicator, could be considered as desirable in wheat breeding theory, for improvement of production efficiency, environmental protection and development of ecological agriculture. However, further investigations of other physiological parameters, their correlations and correlations with yield and grain quality of wheat are necessary to define breeding programs and to obtain reliable results in this area.