This study conducted at Bakrajo Technical Institute Sulaimani, Iraq, to investigates the impact of different fertilizer treatments including foliar nano NPK, bio-fertilizers, and granular NPK (1, 1.5and 2) g L-1 on the growth and yield of sweet pepper (Capsicum annuum). Utilizing Duncan’s Multiple Range Test at a 95% confidence level, the statistical analysis revealed that all fertilizer treatments significantly enhanced plant height compared to the untreated plants or just keep control group, which recorded 52.3 cm. The highest plants were observed by using NPK at (95 cm) with foliar nano NPK (95.0 cm) and bio-fertilizers (93.1 cm). Notably, increasing the fertilizer concentration beyond 1 ml L⁻¹ did not result in further height improvement. A similar pattern was observed for branch number and fresh yield, where 1 ml L⁻¹ concentrations of bio and nano fertilizers outperformed granular NPK. Furthermore, all treatments contributed to a significant raise in dry matter accumulation, with the highest mean dry weight of 297.2 g recorded under 1 ml L⁻¹ foliar nano NPK treatment. Positive correlations among plant height branch number, and leaf count further underscore the beneficial role of nano and bio-fertilizers in enhancing vegetative growth. These results highlight the importance of optimizing fertilizer type and dosage to achieve maximum productivity in sweet pepper cultivation. The study includes that precise application of nano and bio-fertilizers, particularly at 1 ml L⁻¹, offers effective alternative to traditional granular NPK, promoting both growth and yield. However, additional research is recommended to investigate the long-term impacts and to elucidate the underlying molecular mechanisms responsible for these observed growth responses and the treatments applied in this study were a control (no fertilizer), foliar nano NPK fertilizer at 1,1.5, and 2 ml L⁻¹, bio-fertilizer at 1, 1.5, and 2 ml L⁻¹, and granular NPK fertilizer at 1, 1.5, and 2 g L⁻¹.