Response of Two Sunflower (Helianthus annuus L.) Cultivars To Different Levels of Nitrogen

Abstract

Response of two sunflower cultivars namely Aritar-93 and suncom-110 to N levels of 0, 50, 100 and 150 kg haG 1 was studied under field conditions. Sunflower cultivar suncom-110 produced significantly higher plant height, leaf area per plant, 1000-achene weight and achene yield. Plant height, leaf per plant, stem diameter, no. of achenes per disc and achene protein contents were maximum at N level of 150 kg haG 1 . Whereas, oil contents were significantly higher in control. Nitrogen application at 100 and 150 kg haG 1 gave statistically similar achene yields of 15.95 and 16.18 q haG 1 respectively. Application of nitrogen more than 100 kg haG 1 seems to be uneconomical.

Responses of sunflower (Helianthus annuus L.) to irrigation and nitrogen fertilization rates

“…The crude protein content increased up to 20-21% at the highest N rates, whereas it was 17-18% under the control treatment (0 kg ha -1 N). Our results are in agreement with those of Kassem and El-Mesilby (1992), Ayup et al (1998), andOzer et al (2004) who stated that the protein content increased with increasing N rates, whereas the oil content decreased significantly. In contrast, our findings do not correspond with those of Steer et al (1986), and Oyinlola et al (2010) who reported that the oil content of sunflower seeds were increased by nitrogen fertilizers.…”

“…Ozer et al (2004) reported that the head diameter was 20.7 and 20.6 cm for N rates of 120 and 160 kg ha -1 N, respectively, whereas it was 18.5 cm under the control treatment. Our results for the plant height and head diameter are in close agreement with those of Robinson et al (1979), Ayup et al (1998), Sadiq et al (2000), Malik et al (2004), andOzer et al (2004).…”

“…In a previous study, Malik et al (2004) found that, although the highest seed yield (1231.5 kg ha -1 N) was achieved when the crop was fertilized with 130-90-90 kg ha -1 NPK, the highest net benefit was obtained when N, P, and K fertilizers were applied at 110-70-0 kg ha -1 , respectively. In addition, Ayup et al (1998) recorded that nitrogen applications of 100 and 150 kg ha -1 gave statistically similar achene yields and, thus, the application of nitrogen more than 100 kg ha -1 was not economical. In an earlier study, the EONR was found to be approximately 110 kg ha -1 for sunflower plants grown under irrigated conditions in the Eastern Anatolia region of Turkey (Peker, Ozer, 2005).…”

“…As stated in some previous studies, the economic optimum nitrogen rate (EONR) was closely related to the fertilizer N price/crop value ratio (Belanger et al, 2000;Andraski, Bundy, 2005;Sincik et al, 2008), and the EONR was reported to be 100-110 kg ha -1 N to achieve good sunflower production (Ayup et al, 1998;Malik et al, 2004;Peker, Ozer, 2005).…”

“…The higher N rates produced 23-25% larger head diameters than the control treatment. Previous studies indicated that application of nitrogen up to 150 kg ha -1 N increased the plant height when compared with the control treatment (Kassem, El-Mesilby, 1992; Ayup et al, 1998). Ozer et al (2004) reported that the head diameter was 20.7 and 20.6 cm for N rates of 120 and 160 kg ha -1 N, respectively, whereas it was 18.5 cm under the control treatment.…”