INTEGRATED NITROGEN AND BORON FERTILIZATION IMPROVES THE PRODUCTIVITY AND OIL QUALITY OF SUNFLOWER GROWN IN A CALCAREOUS SOIL

Özet

Öz Among biotic and abiotic factors, imbalanced plant nutrition is more indispensable for low sunflower productivity. To assess the interaction behavior of nitrogen with boron on sunflower growth, yield and its oil quality in alkaline-calcareous soils, a field experiment was conducted for two consecutive growing seasons of 2011 and 2012. Sunflower hybrid (Helianthus annuus ‘Hysun-33’) was grown on sandy clay loam soil that was amended with diverse boron rates of 0, 2, 4, and 6 kg ha-1 under variable nitrogen levels of 50% RN, 75% RN, and 100% RN ‘recommended nitrogen’. Extended duration of phenophases like 50% inflorescence emergence, 50% flowering and 50% maturity stages of sunflower was observed with nitrogen and boron application. Plant height, stem and head diameters were increased significantly through individual use of nitrogen and boron nutrients. Concerning sunflower yield and yield related attributes as number of achenes/head, 1000-achene weight and achene yield were significantly improved with 2.0 kg ha-1 boron rate with 100% RN. Application of nitrogen and boron considerably declined the achene oil contents. Achene protein contents were found maximum with boron rate of 2.0 kg ha-1 under 100% RN nutrition. Significant decline in stearic acid and oleic acid contents while considerable increase in palmitic acid and linoleic acid contents was recorded by individual use of nitrogen and boron supplements. However, boron application in combination with nitrogen could play a vital role to improve the productivity and economic performance of sunflower in calcareous soils.Keywords:Sunflower, growth, nitrogen-boron, oil contents, calcareous soil