Document Type : Original Article
Authors
1 Department of Biotechnology and Crop Science, College of Agricultural Engineering Sciences, University of Sulaimani, Sulaimani, Kurdistan, Iraq.
2 Department of Field Crops and Medicinal Plants, College of Agricultural Engineering Sciences, University of Salahaddin-Erbil, Erbil, Kurdistan Region, Iraq.
Abstract
The field experiment was carried out at Qlyasan in the Sulaimani region during the summer season of 2022-2023. It was aimed to investigate the effect of different levels of humic acid on growth, yield and yield components and fatty acids of four sunflower genotypes (Oilseed and Non-oilseed). The first factor included sunflower genotypes; (HS360, Flamme, Dakota and Pionner), while the second factor involved different levels of humic acid, (H0, H1 and H2 that responded 0, 20 and 40 kg. ha-1), respectively. The results showed that, genotypes significantly affected all traits except fatty acids. Pionner var. surpassed others by having the highest values of growth traits; plant height, stem diameter, head diameter and number of seeds per head were by (171.52, 2.07, 17.86 cm and 1314.44 NS/head), respectively. While, Dakota var. was surpassed others in yield and yield component traits; 1000 seed weight, seed, oil and protein yields were by (87.93 g, 3.75, 160.09 and 74.54 t. ha-1), respectively. Generally, humic acid at the level of 40 kg. ha-1 (H2) significantly enhanced growth and yield parameters taken from this present study, it also could be said that it had a great impact on fatty acids in sunflower seeds, while only linoleic, oil and protein percentage improved. Additionally, the interaction between both factors also significantly affected all traits except of some fatty acids were not. Interaction between all genotypes to 40 kg. ha-1 humic acid (V1H2, V2H2, V3H2 and V4H2), were mostly superior of all traits when compared to other treatments. Finally, it could be concluded that humic acid had the important role of enhancing growth, quantity and quality of both sunflower types (Oilseed and Non-oilseed).
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