Response of sunflower genotypes Helianthus annuus L. to amounts of nitrogen fertilizer on growth characteristics and components

Abstract

The field experiment was carried out during the spring and fall season of 2021 in Basra Governorate, Al-Haritha area. The study aimed to studying the response of 6 genotypes of the sunflower which symbolized by the symbol (V ) V1 = local, V2 = moons, V3 = Ishaqi 1, V4 = Ishaqi 2, V5 = Turki Tarzan , V6 = shmoos, And four levels of nitrogen fertilizer symbolized by the symbol (N0) (N = 0 without fertilizer (control), N1 = ( N 100 kg. ha-1 ) , N2 = ( N 200 kg. ha-1 ) , N3 = ( N 300 kg. ha-1 ). According to the complete randomized block design, R.C.B.D. With three replicates and in the order of Split Plot Design (the levels of nitrogen fertilization were distributed in the main plots and the cultivars in the sub-plot). The results have shown superior to the genotypes shmoos, Moons, and Ishaqi2 compared to other cultivars in the studied traits, and most of the yield components as; plant height, leaf area, weight of 1000 seeds total seed yield. In comparison, the study showed the superiority of the fertilizer level 300 kg N. ha- 1 Significant in the traits mentioned earlier.