Abstract
This study evaluated the effects of geographical locations (Adıyaman and Pozantı) and fertilizer types (vermicompost and conventional) on yield, vitamin C content, total phenolic content and other quality parameters of two broccoli cultivars (‘Orantes’ F1 and ‘Robredo’ F1). Over 2 years of field trials conducted in open-field conditions using a randomised complete block design (RCBD) with three replications, both location and fertilizer type had a significant effect on broccoli growth and yield parameters. In Pozantı, conventional fertilizer achieved the highest total yield for ‘Orantes’ F1 (1403.74 kg · da−1) and the highest soil and plant analyzer development (SPAD) chlorophyll meter readings (85.72). In Adıyaman, ‘Robredo’ F1 adapted better, reaching 1256.43 kg · da−1, while ‘Orantes’ F1 had the highest vitamin C (1392.13 mg · kg−1) and phenolic content (434.11 mg · kg−1) with conventional fertilizer. Nitrogen content generally decreased with vermicompost application compared with conventional fertilizer, showing a reduction of up to 24.03% in ‘Robredo’ F1 grown in Pozantı during the second year. By contrast, potassium content increased by 29.39% in ‘Orantes’ F1 (Adıyaman, first year) under vermicompost, while ‘Robredo’ F1 showed a decrease of 32.96% under the same conditions. Iron (Fe) concentrations were higher in ‘Orantes’ F1 with vermicompost, with an increase of 24.98% in Adıyaman and 15.65% in Pozantı, whereas conventional fertilizer led to a much higher Fe content (79.06% increase) in ‘Robredo’ F1 (Adıyaman). Zinc (Zn) levels were generally enhanced by vermicompost, particularly in Pozantı—’Orantes’ F1 where a 41.46% increase was recorded, while ‘Robredo’ F1 in Adıyaman showed a 16.23% decrease. These results emphasise the importance of genotype and location in determining the efficiency of organic vs. conventional fertilizers. These results highlight the need for site-specific fertilizer strategies to optimise broccoli yield and quality.