Water retaining polymer and fertilization in the implantation of Toona ciliata M. Roemer

Abstract

The use of water retaining polymer and the nutrients availability are factors that influence the establishment and development of seedlings in the initial phases of planting. The effect of water retaining/hydrogel polymer and the influence of fertilization dosages were evaluated on survival, growth and nutrient contents of Toona ciliata in the field implantation. The used experimental design was a 2 x 5 factorial design (two hydrogel doses (0 and 400 ml plt-1) and five fertilization combinations (nitrogen (N): N0 = 0, N1 = 62, and N2 = 124 g plt-1; phosphorus (P): P0 = 0, P1 = 75, and P2 = 150 g plt-1, and potassium (K): K0 = 0, K1 = 62, and K2 = 124 g plt-1, named as follows: N0P0K0, N1P1K1, N1P1K1, and N2P2K2), in a randomized complete block design with three replications and five plants per plot in 3 x 2 m arrangement. The concentration of 1 g of hydrogel was applied to 400 ml of water. The survival, root collar diameter and total height were measured at 60, 120, 150, and 180 days after planting. The foliar analysis was performed based on the growth data only of the best treatments (N1P1K1 and N2P2K2) at 180 days. The hydrogel favored survival, but did not show interaction with the different fertilization levels tested for the species. The Australian red cedar responded to the application of dosages of NPK, and the maximum dosage (N2P2K2) provided a higher increase in root collar diameter and height. The application of nitrogen and potassium was efficient for this species. The omission of phosphorus at implantation was the most limiting factor for the growth of Toona ciliata.