Effect of deprivation of selected single nutrients on biometric parameters of cedar seedlings (Acrocarpus fraxinifolius) grown in nutritive solution

摘要

The purpose of this work was to assess biometric parameters of cedar seedlings (Acrocarpus fraxinifolius) associated with visual symptomatology of macronutrients deficiency, growth rate, and content and accumulation of nutrients in aerial parts of seedlings grown in nutritive solution. The trial was established in completely randomized design with seven treatments, four replications, and one plant per pot. Treatments consisted of complete nutrient solution, Hoagland and Arnon, and deprivation of the following selected single nutrients: N, P, K, Ca, Mg and S. Micronutrients were provided to all treatments. The following biometric parameters were assessed 90 days after the transplant: shoot height, root collar diameter, root and shoot dry weight. The Dickson index and the ratio given by roots dry weight and shoot dry weight were obtained, as well as the content and accumulation of nutrients in aerial parts of seedlings. The Sisvar statistical analysis system was run for analysis of variance, and averages were compared by means of Scott-Knott test at 5% significance. Treatments consisting of omissions of macronutrients were found to be limiting factors of plants growth and obtaining of seedlings shoot dry weight in the following order: N > P > K > Ca > Mg > S. Deficiencies of these macronutrients caused visible morphological abnormalities, where common symptoms of deficiency of N, P, K and Ca appeared before symptoms of deficiency of Mg and S. The content of nutrients found in aerial parts of seedlings of A. fraxinifolius grown in nutritive solution was greater for treatments consisting of deprivation of N, P and K. The content of nutrients found for treatments consisting of deprivation of Mg and S was not significantly different from that found for the complete nutrients solution.