Marcha de absorção de nutrientes em urucum (Bixa orellana L.) "tipo cultivado" Piave Vermelha em fase de viveiro

Abstract

The use of natural pigments have boosted due to the growing rules against the use of artificial pigments by food and cosmetic industries. The pigments extracted from the Annatto plant are amongst the few pigments approved by the World Health Organization. Research with different cultivars of Annatto allow us to evaluate the development and physiological activity of the plants through their capacity for extracting nutrients from the soil. With the objective of determining the cumulation of nutrients in the different parts of the Annatto cultivar Piave Vermelha an experiment was carried out in the greenhouse of the Soil Science Department of the University of Lavras, Minas Gerais. The experiment was carried out in a completely randomized design with 6 sampling dates (60, 90, 120, 150, 180 and 210 days) and 4 replications. The plants were cultivated in pots with 5 kg of soil. The soil used was a Dusky Red Latosol whose base saturation had been corrected to 60% by liming. The following nutrients were also added to the soil in mg per kg: 400 N, 200 P, 200 K, 60 Mg, 50 S, 0.5 B, 1.5 Cu, 5.0 Zn, 0.1 Mo. After each sampling time, the plants were separated in roots, stems and leaves and the dry matter content and the levels of nutrients were determined. Based on these levels, the amounts of macronutrients cumulated in each part of the plant and also in the whole plant were calculated. At the end of the period of 210 days, it was possible to conclude that the greatest cumulation of N, Ca and S occurred in the leaves whilst for K, Mg and P, the greatest cumulation was observed in the stems. In all three parts of the plants analyzed, the levels of K, N and Mg were higher than the other nutrients. The total cumulation of macronutrients showed the following sequence: K > N > Mg > P > S > Ca. It is possible to conclude that the greatest cumulation of micronutrients at the end of the period of 210 days occurred in the roots. In all three parts of the plants analyzed, the levels of Fe and Mn were higher than B, Cu and Zn. The total cumulation of micronutrients showed the following sequence: Mn > Fe > Zn > B > Cu.