Limestone and topdress nitrogen application improves the quality of Peltophorum dubium (Sprengel) Taubert (Fabaceae – Caesalpinioideae) seedlings

The liming and mineral fertilization can improve the growth and quality of forest species seedlings. The effects of the application of nitrogen fertilizer rates and limestone on growth and quality of Peltophorum dubium (Sprengel) Taubert seedlings were investigated in this study. Peltophorum dubium plants were grown in 1.4-L polyethylene bags filled with sandy soil under greenhouse conditions. Treatments were arranged in a randomized block design in a 4 × 2 factorial: four of N application rates (0, 100, 200 and 300 mg mg dm–3) and application or non-application of limestone, with four replicates. The plant height, stem diameter, height/diameter ratio and number of leaves were measured at 30, 60, 90 and 120 days after emergence. At 120 days, root volume, shoot and root dry matter, N accumulation in shoots, shoot/root dry matter ratio, and Dickson quality index was also measured. The results reported that limestone and N fertilizer application have a positive effect on most of the growth and quality traits of Peltophorum dubium seedlings, and when Peltophorum dubium seedlings are produced in a substrate consisting of a sandy soil from Brazilian Cerrado, the limestone application and use of 200 mg N dm–3 in topdressing should be recommended to obtain high-quality seedlings.