Print version ISSN 0100-6762
BARROSO, Deborah Guerra et al. Macronutrient deficiency diagnosis in teak seedlings. Rev. Árvore [online]. 2005, vol.29, n.5, pp. 671-679. ISSN 0100-6762. http://dx.doi.org/10.1590/S0100-67622005000500002.
The objective of this work was to characterize visual symptoms of macronutrient deficiency, and to evaluate growth and nutrient content in shoot and root system of Tectona grandis seedlings, cultivated in nutrient solutions lacking macronutrients. The seedlings were grown in commercial substratum, for 4 months, and later transferred to rhizotrons, cultivated for 30 days in complete nutrient solution, and others without N, P, K, Ca, Mg and S. The experiment was arranged in a completely randomized design with five replicates. The solutions were renewed every two weeks and volume completed daily with deionized water, pH around 5,5 + 0,5. The initial Tectona grandis seedling development was affected by the omission of all macronutrients, presenting symptoms that match with the pattern of most cultures. The most intense and immediate damages were observed in the absence of N and Ca causing roots to rot and stopping new roots from growing. The nutritional content of the shoot and root systems of seedlings cultured in complete solution are respectively: 38.0 and 26.9 g kg-1 of N; 8.5 and 4.0 g kg-1 of P; 22.8 and 13.1 g kg-1 of K; 2.3 and 3.7 g kg-1 of S; 10.5 and 2.0 g kg-1 of Ca; 3.0 and 1.7 g kg-1 of Mg; 175.2 mg kg-1 and 3.6 g kg-1 of Fe; 23.1 and 48.1 mg kg-1 of Zn; 4.3 and 17.8 mg kg-1 of Cu; 142.5 and 389.8 mg kg-1 of Mn.
Keywords : Tectona grandis; nutritional deficiency and seedling.