Effects of Agricultural Drainage Water Irrigation and Various Natural Extract Foliar Sprays on Mango Seedlings: An Assessment of Growth, Chemical Content and Antioxidant Activity

The growing scarcity of freshwater resources necessitates alternative irrigation options, such as agricultural drainage water. Mango seedlings, known for their sensitivity to water quality, face both risks and benefits from wastewater use. So, this study evaluated the response of mango seedlings to subjected to three irrigation treatments as main factor: Freshwater, agricultural drainage water and a 50:50 mix of both. Seedlings also received six foliar treatments: Garlic extract, seaweed extract, yeast extract, ginger extract, lemongrass extract and a control (tap water only). Sixty days after treatment initiation, vegetative growth parameters, photosynthetic pigments and leaf nutrient content were measured, alongside biochemical markers (POD, PPO, APX enzymes, proline and malondialdehyde MDA) to assess oxidative stress. After 120 days, antioxidant enzyme activity, proline and MDA levels were re-evaluated to monitor adaptive responses to prolonged stress. The results demonstrated that mango seedlings irrigated with agricultural drainage water and sprayed with garlic or seaweed extract showed significant improvements in growth, photosynthetic pigments and leaf nutrient content compared to other treatments. Also, irrigation with agricultural drainage water significantly increased MDA and proline, indicating oxidative stress. Foliar application of garlic extract reduced MDA and proline, suggesting reduced cellular damage. Garlic and seaweed extracts effectively enhanced antioxidant defenses, particularly under wastewater irrigation. Enzyme activities (POD, PPO, APX) were initially higher with freshwater, but after 120 days, both wastewater and mixed treatments showed increased activity, reflecting adaptation over time. In conclusion, agricultural drainage water, paired with specific natural extracts, can support mango irrigation, promoting resilience and growth.