A pot experiment was carried out to study the effect of different NPK fertilization rates and various Mn and Zn treatments on sandy soil-grown Delonix regia seedlings at the Nursery of Fac. of agric., Minia Univ. during 2016 and 2017 seasons.
The obtained results showed that following: all studied vegetative growth characters, i.e. plant height, stem thickness, crown diameter and leaves, stem and roots dry weights, as well as, the three photosynthetic pigments and leaves % of N, P and K were gradually increased upward parallel to the increase in the applied rate of NPK fertilizers. Similarly, the prementioned vegetative growth and chemical parameters were augmented due to the use of Mn + Zn micronutrient treatments with the effective one being Mn 75 ppm + Zn 75 ppm. It was found that supplying the seedlings with either the medium or high NPK  rate combined with Mn at 75 ppm + Zn at 75 ppm was capable of producing the best growth of Delonix regia seedlings grown in sandy soil.