Impact of Nutrient Omissions on Growth and Biomass Nutrition in Young Plants of Cupuaçu Tree (Theobroma grandiflorum (Willd. ex Spreng.) Shum)

Abstract

Purpose: This study aimed to evaluate the growth, morphological changes, and mineral composition of young Cupuaçu plants subjected to the missing element technique in dystrophic Yellow Latosol. Methods: The experimental design was completely randomized with ten treatments: control (macro + micronutrients), without nutrient application, and individual omission of N, P, K, Ca, Mg, S, B, Zn, in five replications. The nutrients concentrations, nutrients accumulations, and nutrient use efficiency were determined, and visual symptoms, growth biometrics, and plant biomass were measured. Results: Nutrient concentration (-50.43% of N, -24.03% of P, -29.61% of K, -64.22% of Ca, -57.65% of Mg, -65.08% of S, -47.37% of B) and accumulation (-58.66% of N, -55.56% of P, -46.73% of K, -73.21% of Ca, -68.42% of Mg, -66.67% of S, -52.15% of B) were reduced by individual nutrient omissions compared to the control, causing changes in the morphology and coloration of the leaf blade, except for Zn. Plant height, number of leaves, and leaf area were reduced in all individual omissions, resulting in biomass loss in leaves, roots, stems, and total, except for Zn. Total biomass production in young Cupuaçu plants was most restricted by P, followed by Mg, K, Ca, S, N, and B. P deficiency affected the efficiency of utilization of all studied nutrients, but Zn omission did not affect nutrient use efficiency. Conclusions: The results indicate that young Cupuaçu plants in dystrophic Yellow Latosol are sensitive to nutrient omission (N, P, K, Ca, Mg, S, and B), highlighting the need for efficient management in the cultivation system, as nutrient omissions can harm biometric parameters and dry mass production.