Nanofertilizers, which supply nutrients to the plant, are used to replace conventional fertilizers. Iron (Fe) is one of the essential elements for plant growth and plays an important role in the photosynthetic reactions. To study the effects of nano-iron fertilizer on Catharanthus roseus , plants were treated with different concentrations (0, 5 1 0 20, 30, and 40 mM) of iron oxide nanoparticles (Fe2O3) for 70 days. Fe2Onanoparticles increased growth parameters, photosynthetic pigments, and total protein contents in the treated plants signi ficantly. The maximum amounts of growth parameters, photosynthetic pigments, and protein contents were obtained with 30 m M Fe 2 O 3 3 and minimum values of these parameters were found with 0 m M Fe 2 O . The highest value of total alkaloid content was obtained in 0 mM Fe 2 O 3 and the lowest value was observed in control plants. Iron oxide nanoparticles increased potassium, phosphorus, and iron absorption but did not show a signi ficant effect on sodium content.
