Response of camelina Camelina sativa (L.) Crantz cultivars to blended NPSB fertilizer and seed rates in Ethiopia

Abstract Camelina ( Camelina sativa (L.) Crantz), an ancient oilseed crop with biofuel and nutritional value, suffers from low productivity in Ethiopia due to limited improved varieties, underdeveloped seed systems, and suboptimal fertilizer application. This study investigated the effects of cultivar, seed rate, and nitrogen–phosphorus–sulfur–boron (NPSB) fertilizer on camelina growth, agronomic performance, and yield to address this constraint. Field experiments were conducted in the cool sub‐humid highlands of the Hadiya Zone (Lemo and Misha districts) during the 2023 and 2024 cropping seasons. A split‐split plot design evaluated two cultivars (Zeytee‐1 and Syria), three seed rates (5, 7.5, and 10 kg ha − 1 ), and four NPSB fertilizer rates (0, 50, 100, and 150 kg ha − 1 ). Data on soil properties, crop growth, and yield components were collected and analyzed using Statistical Analysis System. Results demonstrated that NPSB fertilization at 100 and 150 kg ha − 1 significantly enhanced dry matter accumulation, branching, and silique production. The Syria cultivar outperformed Zeytee‐1, achieving peak grain yields of 2.53 and 2.54 t ha − 1 with 100 and 150 kg NPSB ha − 1 at the respective sites. A seed rate of 7.5 kg ha − 1 optimized silique production (89 per plant for Syria), while 10 kg ha − 1 maximized grain yield under high fertilization. Grain yield exhibited a strong positive correlation with siliques per plant ( r = 0.979), dry matter ( r = 0.846), and leaf area index ( r = 0.842). For optimal productivity in Hadiya's agroecology, this study recommends integrating the Syria cultivar with 100 kg NPSB ha − 1 and a seed rate of 7.5–10 kg ha − 1 .