Evaluation of the tolerance of canafistula (Peltophorum dubium) under different nitrogen doses

Abstract

The species Peltophorum dubium is widely recognized in Rio Grande do Sul with the common name Canafístula belonging to the Fabaceae family. If there is a deficiency of mineral elements in the soil, the species may experience a decreased response to growth, resulting in slower development. In view of the above, it is intended to evaluate the growth of the Canafístula species in response to different nitrogen dosages. In this way, we sought to determine the plant's response to varying levels of this element. The variables analyzed were: stem diameter, number of leaves, shoot height, shoot mass, root length, root mass and dry mass of both shoots and roots. First, sowing was carried out. On March 20, the seedlings were transplanted to the pots. A randomized block design was used with five replications for each treatment. A total of 20 vessels were subdivided into 4 treatments, T1, T2, T3 and T4 of N doses (0, 40, 80, 120 kg ha-1 respectively). The harvest was carried out on June 19, removing them from the pots. It was left in an open air circulation kiln. The results of the analysis of variance showed a significant effect of the nitrogen doses applied to the Canafístula seedlings for all the variables evaluated except the root dry mass. In all variables, the adjusted regression curve was quadratic and thus the point of maximum technical efficiency for each response variable was determined. The best treatment was T2, which was the critical dose. The T4 that obtained the highest N dose was observed to exceed the critical dose because the culture presented nitrogen toxicity resulting in senescence of the treatment, having as the most severe treatment for the culture. With the results obtained in this research, it was evident that nitrogen plays an extremely relevant role in the production of Canafístula, since it was demonstrated by the results of the analysis of variance a significant effect for all variables except root dry mass.

DOI:https://doi.org/10.56238/sevened2024.023-005