ABSTRACT
Effects of potassium and boron fertilization on sunflower yield, oil content, and quality

Babar Hussain Babar1, Bader Ijaz2, Muhammad Nawaz3, Ahmad Nawaz Gill4, Wei Jian5*, Muhammad Zia Ul Haq2*, Muhammad Talha Aslam2, Muhammad Umair Hassan6, Stacey Gurlee7, Sulaiman Ali Alharbi8, and Mohammad Javed Ansari9
 
Potassium (K) and B are important for phloem translocation, reproductive growth, and grain formation. A 2-yr field study was conducted to evaluate the effect of K and B applied through the soil and foliar application on sunflower (Helianthus annuus L.) Experiments included the soil application of K (62 kg ha-1) and B (5 kg ha-1) and foliar spray of K (1%) and B (0.1%). Furthermore, the soil-applied K and B was supplemented with three foliar sprays of either K, B, or both at 45, 60 and 75 d after sowing. The results revealed that K and B fertilization improved the agronomic parameters of sunflower, including plant height, head diameter, achenes per head, achene weight, yield, seed oil contents and oil quality. The soil applied K at 62 kg ha-1 followed by foliar spray of 1% K + 0.1% B at 45, 60 and 75 DAS resulted in production of taller plants (192 and 172 cm), head diameter (23 and 28 cm), achene per head (954 and 1063), 1000 achene weight (68 and 67.58 g), achene yield (2976 and 2621 kg ha-1), biological yield (11363 and 8430 kg ha-1), oil contents (43.37% and 41.87%), and oleic acid (70.33% and 80.83%) over 2 yr of study. Hence it can be concluded that soil application of 62 kg ha-1 K followed by foliar application of 1% K + 0.1% B is the preferable fertilization strategy for sunflower for improved yield, seed oil contents, and oil quality.
Keywords: Fertilization strategy, foliar nutrient application, Helianthus annuus, omega-6, omega-9, sunflower seed oil.
1Ayub Agricultural Research Institute, Sugarcane Research Institute, Faisalabad, 38850, Pakistan.
2University of Agriculture, Department of Agronomy, Faisalabad, 38040, Pakistan.
3Ayub Agricultural Research Institute, Agronomic Research Institute, Faisalabad, 38850, Pakistan.
4Oilseed Research Institute, Ayub Agricultural Research Institute, Faisalabad, 38850, Pakistan.
5Jilin Agricultural University, Faculty of Agriculture, Changchun, China.
6Jiangxi Agricultural University, Research Center on Ecological Sciences, Nanchang, 330045, China.
7Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing 210095, China.
8King Saud University, College of Science, Department of Botany and Microbiology, Riyadh 11451, Saudi Arabia.
9Mahatma Jyotiba Phule Rohilkhand University, Hindu College Moradabad, Department of Botany, Bareilly 244001, India.
*Corresponding author (weijian@jlau.edu.cn, zia.haq@uaf.edu.pk).