Aplicação de boro em mudas de palma de óleo (Elaeis guineenses Jacq.)

Abstract

It is observed that there is a lack of research on the nutrition of the oil palm, especially on fertilization with the micronutrient boron, which is of fundamental importance for the culture. The objective of this study was to evaluate the development of oil palm seedlings (Elaeis guineensis Jacq.) In response to different doses and forms of B application. The study was carried out in a greenhouse at the Federal Rural University of Amazonia (UFRA), Campão Capitão Poço - PA. The experiment was set up in a completely randomized design (DIC), in a factorial scheme, with five treatments of B (0, 0.1, 0.2, 0.4 and 0.6 g plant-1), fertilizer Bortrac, applied through soil and via foliar, with five replications, totaling fifty experimental plots. Seedlings of the cultivar BRS Manicoré were used and the substrate used was the Yellow Latosol, from an area near the experiment site, collected from the 0-20 cm layer. In order to analyze the development of the seedlings, the evaluation of the plots was carried out every 30 days, after transplanting, and the height of the plant (AP), leaf number (NF), collection diameter (DC) MSPA) and root dry mass (MSR). The application forms of Bortrac fertilizer did not result in a significant difference in the development of oil palm seedlings. All doses of B resulted in the presentation of visual symptoms of toxicity of B. For the variable collection diameter, the best dose was 0.2 g plant-1 of B, equivalent to 1.3 mL of plant-1 of the fertilizer. Possibly the environmental conditions, mainly the temperature, influenced in the aggravation of the symptoms of toxicity of the B. In the conditions in which the seedlings were submitted it is not possible to recommend a dose, since to the minimum caused damages, being therefore enough the content available in the soil at the nursery stage.