Effects of genotype and nitrogen availability on grain yield and quality in sunflower

Abstract

Sunflower (Helianthus annuus L.) conventional (CONV) and high oleic (HO) genotypes differ in yield and quality. Nitrogen affects grain yield, quality, and by-products protein concentration. The objective was to evaluate the effect of genotype and N on grain yield, oil (OG) and protein (PG) concentration in grain and in by-products (PM). The effect of genotype was evaluated in Exp. 1 with 7 CONV and 7 HO hybrids, at two planting dates (PD early and late). The effect of N (Exp. 2) was evaluated in 10 locations (3 with CONV and 7 with HO), under six N rates (0, 30, 60, 90, 120, and 150 kg N ha–1). We determined yield, OG, PG and PM . For the early PD of E1, yield was higher in HO than CONV genotypes (3822 kg ha–1 vs. 3495 kg ha–1). In Exp. 2, N increased yield in 50% of the locations (HO: 586; CONV: 597 kg ha–1). In Exp. 1, genotype did not affect OG, but PG was higher in HO than in CONV ones (18.0 vs. 16.8%, respectively). In Exp. 2, N did not affect OG, but increased PG in both types of genotypes. Consequently, PG/OG ratio increased with N rates. The higher PG, was also reflected in higher PM (44.0% HO and 38.8% CONV, respectively). Increases of 2.5% points in PG resulted in increases of 5.6 in PM . Therefore, the application of N would allow obtaining high yields and PG without detrimental effects on OG, improving the quality of grains and by-products.