Abstract :
O presente trabalho objetivou avaliar o estado nutricional da bananeira-'Prata-ana' durante cinco ciclos de cultivo com adubacao organica, no municipio de Botucatu-SR As plantas foram adubadas com composto organico produzido a partir de serragem de madeira e esterco bovino, em que os tratamentos foram constituidos de doses desse composto (0; 98,5; 197,0; 290,5 e 394,0 g de K2O/planta). Empregou-se delineamento experimental em blocos casualizados, com cinco tratamentos e cinco repeticoes. No florescimento das plantas em cada ciclo, foram retiradas amostras foliares de duas plantas por parcela para serem analisados os teores de nitrogenio, fosforo, potassio, calcio, magnesio, enxofre, boro, cobre, ferro, manganes e zinco. A maior parte dos macronutrientes presentes nas folhas nao foi influenciada pelo incremento de doses de composto organico. No decorrer dos ciclos avaliados, os teores foliares de nitrogenio, fosforo, potassio, enxofre, boro, ferro e manganes diminuiram, enquanto o calcio e o magnesio se acumularam nas plantas. Os teores de potassio estavam abaixo dos padroes para a cultura no Estado de Sao Paulo, em todos os anos avaliados, mesmo assim as plantas nao apresentaram sintomas de deficiencia ou queda de producao, inferindo-se que a faixa considerada como adequada para a cultivar pode ser inferior aos padroes atualmente adotados. Termos para indexacao: Musa sp., banana, adubacao organica, nutricao, potassio. This work aimed to assess the nutritional status of banana 'Prata-ana' leaves for five cycles of cultivation with organic fertilization, in Botucatu, SP, Brazil. Plants were fertilized with organic compost produced with wood residue and cattle manure. Treatments consisted of the compost rates (0, 98.5, 197.0, 290.5 and 394.0 g of K2O per plant). The experiment was arranged in a randomized block design, with 5 treatments and 5 replications. At blooming, leaves of two plants were collected to analyze the levels of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese and zinc. The content of most nutrients in leaves was not influenced by the increasing rates of organic compost. During the cycles assessed the levels of leaf nitrogen, phosphorus, potassium, sulfur, boron, iron and manganese decreased, whereas there was an increase of the calcium and magnesium contents. The levels of potassium were below the standards for the cultivar in the state of Sao Paulo, for all the years studied, and yet plants did not show symptoms of weakness or collapse of production. It can be conclude that the range considered appropriate for the culture may be lower than the standards currently adopted. Index terms: Musa sp., banana, organic fertilization, nutrition, potassium.