The fertilization with micronutrients is poorly studied for banana production, especially boron (B) application, which affects the development of apical meristems. This experiment aimed to study responses of B fertilization with different rates and application methods in banana plant 'Grande Naine'. The experimental design was in randomized block and factorial scheme with three rates (0.85, 1.70 and 3.40 g plant-1) and three fertilizer application methods (soil, leaves and tiller hole chopped) and a control, without B application, using boric acid as the source of B. Treatments effects were evaluated by B availability on soil, plant grown, plant nutritional status and by the yield. Treatments effects were submitted to variance analysis and when significant it was adjusted by regression equations. The B application on soil and in the leaves increased this micronutrient content in topsoil (between 1.0-1.5 mg kg-1, with the highest rate of the nutrient) and a corresponding increase up the soil layer to 20-40 cm, as a result of leaching. The contribution of foliar fertilization increasing the content in the soil was due to the washing and by draining the fertilizer solution from the leaves to the soil surface. Moreover, there was no effect of B availability in the soil when the fertilizer was applied in the tiller hole chopped (~0.3 mg kg-1 of B). It was also verified that there were no effects of B application on banana plant growth (height and pseudostem diameter) at the blooming stage. In leaf samples, collected each 15 days, it was observed that when the micronutrient was applied in the tiller hole chopped, leaf B concentration was higher and lasted up for one month. However, in the last foliar sampling (at blooming) it was observed that there was no effect of application methods on leaf B concentration (~20 mg kg-1). There were no effects of fertilization in yield according to rates and application methods of B, but the application on the tiller hole chopped promoted an increased accumulation of this micronutrient in the bunch due to the applied rates. Under the conditions of this experiment, it can be concluded that B application did not influenced the development and production of banana plant 'Grande Naine' according to the rates and application methods of this micronutrient.
Musa spp.; application methods; micronutrient
