THE BEHAVIOR OF FOUR WINTER WHEAT GENOTYPES UNDER DIFFERENT RATES OF NITROGEN FERTILIZER

In agriculture water and nitrogen are the main factors that influence crop production in all regions. Interactions between water and nitrogen fertilization are complicated. The present study investigated the influence of nitrogen fertilization rate and rainfall distribution on plant height, grain yield and grain protein content of four winter wheat varieties in a three years field experiment in Turda, Romania. To establish the relationships between nitrogen fertilization rate, rainfall distribution and grain yield the follow parameters was determined: the rain use efficiencies (RUE), nitrogen agronomic efficiency (NAE) and nitrogen use efficiency (NUE). Andrada and Codru had a significant higher RUE which means that this genotypes produced higher rate of grain yield per unit rainfall than Arieşan and Taisa. The highest NAE was recorded by Taisa which means that this cultivar has the highest ability to increase yield in response to the rate of nitrogen fertilizer applied. Andrada and Codru had the highest value of NUE, which means that these cultivars have the ability to use more efficiently the nitrogen to obtain a higher yield.