Sintomas de deficiência nutricional em mudas de Acacia holosericea em resposta à omiss?o de macronutrientes

摘要

Acacia holosericea is a leguminous species that has been extensively used in land reclamation programs. The knowledge of its nutritional symptoms allows the identification and correction of deficiencies in individuals planted in degraded substrates. The aim of this work was to characterize the behavior of seedlings of A. holosericea submitted to different nutritional solutions with absence of macronutrients. The treatments consisted of seven nutritional solutions: 1) Complete solution (SC); 2) SC - N; 3) SC -P; 4) SC -K; 5) SC -Ca; 6) SC -Mg; 7) SC -S. Treatments -N and -Mg were the ones that most affected biomass production. Decrease in biomass production occurred in the following order: -N = -Mg > -K > -S > -Ca > SC > -P. The -N treatment plants formed nodules in their roots, showing higher concentrations of N than those of the SC treatment. Except for the SC and -P treatments, all the other treatments showed nutritional deficiency symptoms. The absence of S has led to a change in the natural disposition of new leaves of A. holosericea.