Estabelecimento de normas DRIS em cafeeiro conilon orgânico ou convencional no estado do Espírito Santo Establishment of DRIS norms for organic and conventional conilon coffee in the State of Espírito Santo (Brazil)

Abstract

O café conilon (Coffea canephora) ocupa grande importância no cenário sócio-econômico no Espírito Santo, e o seu cultivo, principalmente, de forma orgânica é crescente e representativo; no entanto, faltam informações sobre valores de referência de teores da folha, bem como um diagnóstico nutricional. O objetivo deste trabalho foi estabelecer e comparar padrões de referência e propor valores de teores foliares considerados adequados, a partir de lavouras de alta produtividade de cafeeiros conilon cultivados de forma orgânica ou convencional na região norte do estado do Espírito Santo. Determinaram-se os teores foliares de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn em 40 lavouras sob cultivo convencional e 56 lavouras sob cultivo orgânico. Foram selecionadas para estabelecer as normas DRIS 23 lavouras sob cultivo convencional e 22 lavouras orgânicas. Para comparar as normas estabelecidas, utilizou-se o teste "t" de Student, a 1 %, e realizaram-se diagnósticos nas lavouras orgânicas e convencionais, por meio das normas DRIS, com a incorporação da matéria seca, verificando a freqüência do nutriente cujo índice foi mais negativo e mais positivo. Os nutrientes que mais vezes apresentaram índices DRIS mais negativos nas lavouras orgânicas foram Mn, Cu, N e P e, nas lavouras convencionais, foram Mn, Cu e P. Os resultados evidenciam que as normas DRIS são específicas a cada forma de cultivo.Conilon coffee (Coffea canephora) is very important for the economy of the state of Espírito Santo and its organic cultivation is increasing. However, there is a lack of information on leaf reference values for this form of management, as well as a nutritional diagnosis. The objective of this study was to establish and compare reference patterns and to propose adequate values of leaf nutrient concentrations obtained on high yielding conilon coffee plantations, cultivated under organic or conventional systems, in the northern area of Espírito Santo State. Leaf concentrations of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn were determined in plantations under conventional and 56 plantations under organic cultivation. To establish DRIS norms, the data of 23 plantations under conventional cultivation and 22 organic plantations were used. The established norms were compared by the Student "t" test at 1 % probability. Organic and conventional plantations were diagnosed through DRIS norms with the incorporation of dry matter data in the analysis. The frequency of the nutrients with the most negative or most positive index was verified. The most frequent nutrients with more negative DRIS index on the organic plantations were Mn, Cu, N, and P. In the conventional plantations, the most frequent nutrients with more negative index were Mn, Cu and P. The results suggested that each cultivation system should be diagnosed by specific DRIS norms.

Keywords

• Coffea canephora
• DRIS
• diagnóstico nutricional
• equilíbrio nutricional
• Coffea canephora
• DRIS
• nutritional diagnosis
• nutritional balance