Irrigation water of different sources affects fruit quality attributes and heavy metals contents of un-grafted and commercial mango cultivars

Abstract

In peri-urban areas, waste water is used to irrigate orchards due to scarcity of fresh water which increases heavy metals contents in soils, leaves and fruits. Due to excessive waste water irrigations, heavy metals enter into the food chain, which eventually causes metabolic disorders in humans. The present study was envisaged to investigate the effects of canal, tubewell and sewage water on the quality of mango fruits and heavy metals accumulation in soils, leaves and fruits. Leaf and fruit samples from an un-grafted (Desi mango) and six commercial cultivars of mango (Anwar Rataul, Aman Dusehri, Sufaid Chaunsa, Samar Bahisht Chaunsa, Kala Chaunsa and Anwar Rataul Late) grafted on Desi mango were collected from different mango orchards located in peri-urban areas of Multan (Pakistan) and analyzed for some physico-chemical attributes and heavy metals contents. Soil samples were also taken from these orchards irrigated with different water sources to assess the soils' heavy metals status. A significant variation was observed among the mango cultivars for their physico-chemical attributes. Sewage water irrigation improved total soluble solids (TSS), titratable acidity, ascorbic acid content, total phenolics, total carotenoids, total flavonoids and antioxidant activity of mango fruits. However, it did not affect fruit weight and shelf life. Among the heavy metals, copper and nickel contents were found in greater amounts in soils, leaves and fruits of sewage water irrigated orchards than canal and tubewell water irrigated ones. However, zinc and cadmium were not detected in any soil, water, leaf or fruit sample. The interaction among the sources of irrigation and the mango cultivars was significant for copper accumulation in different soil layers, copper and nickel accumulation in leaves of different mango cultivars, and fruit weight, titratable acidity, ascorbic acid content, total flavonoids and shelf life of mango fruits.

Keywords: Canal water; Copper; Mangifera indica; Nickel; Sewage water; Tubewell water.