Nutrient suppression effect on growth and development of Ochroma pyramidale (Cav. ex Lam.) Urb. seedlings

Introduction: Ochroma pyramidale (Cav. ex Lam.) Urb. is a species with high potential for use in commercial reforestation. Knowledge of nutrient requirements in nursery increases the chances of success in the field by generating plants with adequate morphological and physiological characteristics. Objective: To identify the key nutrients for O. pyramidale growth in nursery and to characterize the associated visual symptoms of deficiency. Materials and methods: The design was completely randomized with 10 treatments: one treatment without fertilization, one treatment with complete fertilization (CF), and eight resulting from the CF treatment with suppression of N, P, K, Ca, Mg, S, B and cationic microelements (Mn, Fe, Cu and Zn). The effect of each treatment was determined by height, root collar diameter, aboveground dry biomass, root dry biomass, leaf area and relative growth rate. An analysis of variance and separation of means was performed using the Tukey's test (P < 0.05). Results and discussion: Nutrient suppression had significant effects (P < 0.05) on growth after six months in nursery. P was the most limiting element, followed by N. The other treatments showed no significant differences compared to the FC treatment. N suppression caused yellowing, and lack of P caused necrosis with subsequent death and detachment in leaves. B suppression showed no clear deficiency symptoms. Conclusion: O. pyramidale showed high nutrient uptake efficiency. Only N and P strongly limited its development, which represent the key nutrients for the species.