Sunflower (Helianthus annuus L.) is one of the most important oilseed crops worldwide, requiring balanced nutrient management to achieve high productivity, superior seed quality, and sustainable agricultural performance. Foliar fertilization has become an increasingly adopted agronomic practice because it complements soil fertilization, improves nutrient availability during critical growth stages, and enhances plant physiological processes associated with growth and yield formation. The present study evaluated the effectiveness of different foliar fertilization strategies applied under field conditions in western Romania. Four treatments, including an untreated control, foliar NPK fertilization, micronutrient application, and a combined NPK plus micronutrient treatment, were compared in terms of seed yield, thousand-seed weight, oil content, and plant height. The combined application of macro- and micronutrients consistently produced the highest values for all evaluated parameters, indicating a synergistic effect on plant growth and productivity. The observed responses highlight the importance of balanced foliar nutrition in supporting photosynthetic activity, nutrient uptake, assimilate translocation, reproductive development, and seed filling. Improvements in vegetative growth were accompanied by increased seed yield, enhanced thousand-seed weight, and higher oil content, demonstrating the beneficial influence of foliar fertilization on both crop productivity and seed quality. These findings confirm that foliar fertilization represents an effective complementary nutrient management strategy capable of improving sunflower performance, increasing nutrient-use efficiency, and supporting the development of more productive and sustainable cropping systems under modern agricultural conditions.

foliar fertilization; sunflower; micronutrients; NPK; seed yield; oil content

agronomy

Presentation: poster