Akademik Veri Yönetim Sistemi
International Journal of Plant Production, cilt.20, sa.2, 2026 (SCI-Expanded, Scopus)
The growing concerns regarding the environmental impacts of chemical fertilizers have increased interest in bio-based inputs for sustainable crop production. This study investigated the effects of commercial Ascophyllum nodosum seaweed extract and humic & fulvic acid on germination, physiological traits, yield, and biochemical responses of sunflower (Helianthus annuus L.) under laboratory and field conditions. The experimental treatments consisted of T0(–) (non-fertilized control), T0(+) (chemical fertilizer), T1 (seaweed extract), T2 (humic and fulvic acid), and their combined application T3. Laboratory experiments showed that T1 and T2 significantly enhanced germination percentage (%2.17, %3.26, respectively), shoot height (%53.57, %49.11) and root length (%47.6, %50.0) compared to the control treatments. Although varying according to growth stages, field study results have shown that T1, T2, and T3 relatively improved water content, chlorophyll concentration, plant height, and increased proline accumulation compared to both control treatments. These treatments also reduced the number of days to flowering and physiological maturity. Seed yield did not differ significantly among fertilized treatments. However, crude oil yield was significantly higher in T2 and T3. The results demonstrate that bio-based applications, particularly humic & fulvic acid and its combination with seaweed extract, can improve physiological performance and oil productivity in sunflower. These findings support the use of bio-based fertilizers as sustainable alternatives or complements to chemical fertilization.