The present study was carried-out at Antoniadis Research Branch, Horticultural Research Institute, Agriculture Research Center (ARC), Alexandria, Egypt during two successive seasons of 2018 and 2019. The aim of this study was to evaluate the effects of irrigation water contaminated with lead on the growth of Polianthes tuberosaplants and the possibility of using tryptophan spray treatments to overcome the effects of lead pollution. Corms of Polianthes tuberosawere planted individually in plastic pots (20 cm diameter) filled with 5 kg of sandy soil. The lead-contaminated irrigation water treatments were 0,100, 200 and 300 mg/L were applied. The plants were also monthly sprayed with tryptophan at concentrations of 0, 250 and 500 mg/L.
           The results showed that for vegetative growth parameters there was no significant difference in the interaction between lead polluted water of irrigation and foliar spray by tryptophan, while a significant reduction was observed in all parameters after irrigation with lead polluted water and a significant increase in vegetative growth parameters was observed after 500 mg/L tryptophan application. For chlorophyll and carbohydrate content, the highest significant value was obtained in plants irrigated with tap water and sprayed with 250 mg/L tryptophan while the highest significant level of lead content in leaves and corms was obtained due to treatment by 300 mg/L lead without application of tryptophan.