Determination of grain yield and nitrogen use efficiency and genotypic variation in some agricultural traits of pop corn (Zea mays everta Sturt) under different nitrogen fertilizer applications

The study was conducted to evaluate, the effect of different nitrogen fertilizer types [(Nitropower 33 and Novatec 32 (slow-release fertilizer)] and nitrogen doses [0, 8, 12, 16, 20 kg/da N] on some agronomic traits, nitrogen use efficiency and heritability (H) in popcorn varieties (PC912, SH3077) were determined. The research was carried out in the experimental field of the Faculty of Agriculture of Isparta University of Applied Sciences in the vegetation period of 2021 and 2022 according to the randomized blocks split split experimental design. The effect of cultivar, fertilizer and dose applications on yield and quality traits varied according to years, they were found to be statistically significant. It was determined that the effect of different fertilizer applications on tasselling and silking time, plant height, first ear height, number of ear per plant and grain yield were statistically significant and slow-release fertilizer application had a positive effect on grain yield. The effect of nitrogen dose applications was found to be statistically significant in all characters. The dose of nitrogen increased, tasselling, silking time and starch ratio decreased, while plant height, ear length, ear diameter, number of grains on ear, thousand grain weight, number of ear per plant, explosion volume, explosion grain ratio, grain yield, grain protein ratio increased. Again, as the dose increased, the amount of nitrogen removed by the above-ground parts increased, while nitrogen uptake and utilization efficiency decreased. Nitrogen utilization efficiency showed variability in nitrogen doses. Broad sense heritability was found to be high in number of rows in ear, thousand grain weight and number of ear per plant, which are effective in grain yield. As a result, it was determined that both popcorn varieties can be grown under Isparta conditions and slow-release fertilizer application provided a significant increase in yield and quality characteristics of popcorn varieties.