Production performance of sesame cultivars under different nitrogen rates in two crops in the Brazilian semi-arid region

Sesame is an oleaginous plant that requires suitable management in the field to achieve satisfactory production; however, to better understand the requirements of the culture, it is necessary to obtain more information on the behavior of sesame cultivars, in relation to the nutrition and edaphoclimatic factors that can interfere with its response. Therefore, the aim of this work was to evaluate the production components of fertirrigated sesame cultivars, in the northeastern semi-arid region of Brazil, as a function of nitrogen (N) fertilization in two crops. The experiments were conducted at the Rafael Fernandes Experimental Farm, which belongs to the Universidade Federal Rural do Semi-Árido (UFERSA), from February to May (first crop) and July to October (second crop), in the year 2016. The experimental design was of a randomized complete blocks type with four replications, with the treatments arranged in a split plots scheme, where in the plots were assigned five rates of N (0, 30, 60, 90, and 120 kg ha⁻¹) and in the subplots four sesame cultivars (CNPA G2, CNPA G3, CNPA G4, and BRS Seda). The evaluated variables were N content in the diagnostic leaf (NCDL), number of capsules per plant (NC), plant dry mass (PDM), seed yield (SY), oil content (OC), and protein content (PC). The maximum values of the variables studied were obtained at a rate of 120 kg ha⁻¹ of N. The cultivar CNPA G4 presented the highest productive performance in comparison to the other cultivars, and the cultivar BRS Seda had the highest oil content in the seed. The second crop (July to October) obtained the best agronomic performance for the sesame. Regarding the protein content, the cultivars CNPA G3 and CNPA G4 obtained the highest at a rate of 120 kg ha⁻¹ of N. The second harvest also provided higher levels of protein in the seed, independent of the cultivar evaluated.