Nitrogen fertilization and sowing density on yield and physiological quality of wheat seeds

The optimal combination between sowing density and nitrogen (N) fertilization rate is a challenge for the production of high-quality seeds, considering the diversity of genotypes and environments. This study aimed to evaluate the yield and physiological quality of wheat seeds as a function of sowing density and N rate, under different edaphoclimatic conditions. The experiment was carried out in three environments (Londrina, Cascavel, and Ponta Grossa) in a randomized block design with four replications, considering a 2 x 3 x 4 factorial arrangement composed of two genotypes (BRS Anambe and WT 15-025), three sowing densities (250, 350, and 450 seeds.m(-2)), and four N rates (0, 40, 80, and 120 kg.ha(-1)). The following seed features were evaluated: yield, first germination count, final seed germination, seedling emergence, emergence speed index, seedling length, and seedling dry matter. Seed yield varied as a function of environment and genotype. BRS Anambe produced seeds with higher physiological quality. The optimal combination between sowing density and N rate that provided the more suitable economic yield, without affecting the physiological quality of wheat seeds, varied with the environment and was estimated in 250 seeds.m-2 x 0 kg.ha(-1) N for Londrina and Cascavel, and 350 seeds.m(-2) x 18 kg.ha(-1) N for Ponta Grossa.