were 16.56 μg/ml and 17.69 μg/ml, respectively compared to control (20.89 μg/ml). On the other hand, the values of IC50 for Southern star cultivar treated with organic and bio-organic fertilizers were 19.42 μg/ml and 19.69 μg/ml respectively compared with control NPK (24.79 μg/ml). While, The IC50 value for BHT was 10.07 μg/ml. The extracts of both cultivars were capable of directly reacting and quenching DPPH radical. Calabrese cultivar exhibited the highest activity when compared with Southern star cultivar.