Effects of urea on growth and photosynthetic metabolism of two aquatic plants (Cabomba caroliniana A. Gray and Elodea nuttallii (Planch.) H. St. John)

•Growth of E. nuttallii and C. caroliniana was hampered by 10 mg L−1urea-N.•Photosynthesis in E. nuttallii and C. caroliniana was restrained by 10 mg L−1urea-N.•PSII was more susceptible to higher urea than PSI in E. nuttallii and C. caroliniana.•E. nuttallii was more sensitive and vulnerable to urea than C. caroliniana.