Response Foliar Applied with Ascorbic Acid to Mitigate the Detrimental Impact of Lead Pollution in Water Irrigation on Jatropha curcas Plants

The present study was carried out at Antoniadis Research Branch, Horticultural Research Institute, A.R.C. Alexandria, during the two successive seasons of 2022 and 2023. This study aimed to evaluate the effects of irrigation water contaminated with lead on Jatropha curcas plants grown in sandy soil, and the possibility of using ascorbic acid spray treatments to overcome the effects of lead pollution. Seedlings of Jatropha curcas were planted individually in plastic pots (30 cm diameter) filled with 8 kg of sandy soil. The contaminated irrigation water treatments were four concentrations of lead 0,100, 200, and 300 mg/l applied. The plants also were sprayed with ascorbic acid at concentrations of 0, 250, and 500 mg/l by monthly spraying in both seasons. The results showed that for vegetative growth parameters, there was no significant difference in the interaction between lead concentrations and foliar spray by ascorbic acid. While a significant reduction was observed in all parameters after irrigation with lead-contaminated water and a significant increase in vegetative growth parameters was observed after 500 mg/l ascorbic acid application. For chlorophyll and carbohydrate content the highest significant value was obtained from plants irrigated with tap water and sprayed 500 mg/l ascorbic acid while the highest significant amount of lead content in leaves, stem and roots was obtained from the treatment of 300 mg/l lead without application of ascorbic acid. The results showed that the interaction between lead concentrations and ascorbic acid foliar spray about vegetative growth indices was not significantly different.