Response of grain yield and plant traits to ammonium nitrate fertilization in selected Triticum genotypes

Abstract

The genus Triticum encompasses a wide genetic diversity, including both ancient and modern wheat species that are important for agriculture and food security. This study aimed to evaluate the effect of ammonium nitrate (AN) fertilization on grain yield, plant height, and spike length across 23 genotypes of Triticum including: spelt (T. spelta), durum (T. durum), einkorn (T. monococcum), emmer (T. dicoccum), compactum (T. compactum), sphaerococcum (T. sphaerococcum), and triticale, under field conditions characterized by low rainfall. The experiment was conducted over two growing seasons (2021–2023) at the Maize Research Institute ―Zemun Polje,‖ Serbia, using a randomized complete block design with two replications. Treatments consisted of a control and fertilization with 150 kg/ha AN applied on March 15. Except for triticale, where yield under AN- fertilized plots was 1% higher, all species showed higher grain yield in control plots compared to AN-fertilized plots, with reductions ranging from 0.32% (durum) to 88.8% (einkorn). This decline is attributed to the dry environmental conditions during the growing seasons, which likely limited water availability and reduced water use efficiency under increased nitrogen supply. Statistically significant differences (P < 0.05) between treatments were observed for grain yield in spelt and einkorn, as well as plant height in durum and spelt genotypes. Notably, ancient wheat genotypes such as einkorn and emmer showed greater sensitivity to nitrogen fertilization under dry conditions, likely due to their evolutionary adaptation to low-input environments. Spike length differences were not significant across treatments. The ANOVA revealed highly significant main effects of genotype, year, and treatment, as well as their two- and three-way interactions (P < 0.05). The significant Genotype × Treatment interaction confirms that genotypes responded differently to fertilization. Post-hoc Tukey‘s test further grouped genotypes based on yield performance: triticale breeding line ZP 34-15 and durum variety Agaton showed the highest mean yield and were significantly different from the majority of others, while four spelt lines were in the lowest-yield group. These results emphasize the need for integrating genetic diversity with site-specific fertilization strategies to improve wheat productivity and resilience under changing climatic conditions