SUSTAINABILITY OF CITRUS RETICULATA L. BLANCO. AND MANGIFERA INDICA L. IS RELATED TO ANTIOXIDATIVE DEFENSE UNDER SPATIAL AND TEMPORAL FLUCTUATIONS OF SOIL AND IRRIGATION WATER.

Spatial and temporal variability for the quality of surface and ground irrigation water and its impact on soil characteristics were assessed for local farms of Citrus reticulata L. Blanco. (Citrus) and Mangifera indica L. (Mango). Electrical Conductivity (EC), Potential Hydrogen (pH), Sodium (Na⁺), Calcium magnesium (Ca⁺² + Mg⁺²), Chromium (Cr), Lead (Pb), Nickel (Ni), Zinc (Zn), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) were determined. Ground water at an aquifer of (30-40 cm) (0.57 and 0.88 mg L^-1), and two depths of soil profiles (0.97 and 2.29 mg kg^-1) had more Cr and Pb, respectively. Biochemical characteristics of the species varied spatially and temporally except the chlorophyll content. Lipid peroxidation via MDA production became evident. An enhanced activity of enzymatic Superoxide dismutase (SOD), Catalase (CAT), Peroxidase (POD) and non-enzymatic components (Ascorbic acid, Carotenoids, Phenols, Sugars) was noticed but the higher resilience in mango can be attributed to non-enzymatic defense. The bioaccumulation of Cr and Pb declined markedly (P ≤ 0.001) in species from roots to aerial tissues. Citrus pulp contained a significant (P ≤ 0.001) amount of Cr, and Pb. The study suggested strict environmental monitoring for biodiversity and conservation. However, metal accumulation in the edible portion of citrus seemed to be of great concern for food safety. [ABSTRACT FROM AUTHOR]