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 cadmium on the growth of Polianthes tuberosa plants and the
possibility of using tryptophan spray treatments to overcome the effects of cadmium pollution. Corms of Polianthes
tuberosa were planted individually in plastic pots (20 cm diameter) filled with 5 kg of sandy soil. The Cadmium
contaminated irrigation water treatments were 0,100, 200 and 300 mg/L were applied. The plants were also monthly
sprayed by 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 cadmium polluted water of irrigation and foliar spray by tryptophan, while a significant reduction was observed
in all parameters after irrigation with cadmium 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 cadmium content in leaves and corms was obtained due treatment by 300 mg/L cadmium without application of
tryptophan.