Response genotypes of sunflower (Helianthus annuus L.) and amount of nitrogen fertilizer on growth characteristics, oil yield, and its percentage

Abstract

The field experiment was conducted during the spring and autumn seasons of 2021 in the Al-Haritha area, AL- Basra Governorate, to study the response of six genotypes of sunflower (Local, Aqmar, Ishaqi 1, Ishaqi 2, Turki Tarzan and Shmoos) and four levels of nitrogen fertilizer control treatment N0, N1 = (N100 kg. ha -1), N2 = (N200 kg.ha-1) and N3 = (N300 kg.ha-1) according to the complete randomized block design RCBD with three replications in the order of the split-plot design (the levels of nitrogen fertilization were distributed in the main plot and the varieties in the secondary Sub-plot). Results showed the superiority of the Shmoos genotype with the highest average number of leaves that, reached (27.05 and 29.41) leaves. plant-1. while the nitrogen fertilizer effect showed a superior fertilizer level of N3, which gave (26.32 and 29.94) leaves. plant-1. As for characteristic of fertility percentage, there were no significant differences between the genotypes (Local, Aqmar, and Tarzan) for the spring season; it appears the superiority of fertilizer level N3, which gave (93.79 and 91.79), Shmoos genotype was superior with the highest average yield of an individual plant (78.50 and 84.73) gm.plant-1 compared to the local genotype, which gave the lowest average of (44.80, and 51.23) gm.plant-1 for the two seasons, respectively, and N3 level of fertilizer, which gave average (77.82 and 88.88) gm.plant-1 and local composition outperformed the proportion of oil (39.55 and 41.13%) and the Shmoos genotype in the total oil yield (1161.4 and 1461.3) kg.ha-1, while this study showed the superiority of the fertilizer level N0 with the oil percentage, which gave (39.63 and 43.65%). As for the total oil yield, the composition was superior to Shamus by giving the highest mean of oil yield (1161.4 and 1461.3) kg.ha-1 for two seasons, respectively, and the superiority of the fertilizer level N3, which gave the highest oil yield (1,247.6 and 1673.6) kg.ha-1, for two seasons, respectively. Keywords: sunflower, genetic structures, nitrogen fertilizer