Normas DRIS de verão e inverno, para o cafeeiro arábica da região de Manhuaçu - MG

Abstract

A região de Manhuaçu na Zona da Mata de Minas Gerais se destaca como um grande pólo de produção de café onde existem muitas lavouras de produtividade elevada, portanto, este trabalho pode contribuir na realização de diagnósticos dessas lavouras, pois diferente de outros trabalhos suas normas foram estabelecidas para verão utilizando lavouras com produtividade média de duas colheitas igual ou superior a 60 sacas por hectare e para inverno (igual ou superior a 50 sacas). Assim, o objetivo deste trabalho foi estabelecer e comparar os padrões de referência (normas Dris) de verão e de inverno, para a região de Manhuaçu MG. Determinaram-se os teores foliares de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn em 200 lavouras. Foram selecionadas para estabelecer as normas DRIS (média, desvio padrão e coeficiente de variação), 22 lavouras com alta produtividade tendo suas amostras foliares coletadas no verão e, 18 lavouras com amostragem foliar feita no inverno com alta produtividade. Para comparar as normas estabelecidas, utilizou-se o teste "t" de Student. Houve diferenças das relações de nutrientes, entre as duas épocas de amostragem nas seguintes relações: N/Fe, P/Ca, P/Fe, P/Zn, P/Fe, P/Mn, P/Ca, Ca/S, Mg/Fe, S/Fe, S/Zn, Fe/N, Fe/P, Fe/S e Zn/S a 1%, N/Ca, N/Mn, N/Zn, P/Mg, P/Mn, K/S, Ca/N, Ca/Fe, Mg/P, Mg/S, Mg/Mn, S/Ca, S/Mn, B/P, Fe/K, Fe/B, Mn/N, Mn/P, Mn/S e Zn/N a 5% e P/K, K/P, P/Ca, K/Zn, Ca/K, Ca/Mn, B/N, B/S, Cu/Fe, Cu/Mn, Fe/Ca, Fe/Mg, Mn/K, Zn/Fe, Zn/Mn a 10%, permitindo a afirmar que há diferenças entre as duas normas, indicando que estas, além de serem regionalizadas, devem ser específicas para cada época do ano (verão e inverno).

The region of Manhuaçu Zona of Mata of Minas Gerais if detaches as a great polar region of coffee production where many coffee crop of raised productivity exist, therefore, this work can contribute in the diagnosis accomplishment of these coffee crop, therefore different of other works its norms had been established for summer using coffee crop with equal or superior average productivity of two harvests the 60 bags for hectare and for winter (equal or superior the 50 bags). Thus, the objective of this work was to establish and to compare the standards of reference (Dris norms) of summer and winter, for the region of Manhuaçu - MG. Had determined foliar texts of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn in 200 coffee crop. They had been selected to establish the norms DRIS (average, shunting line standard and coefficient of variation), 22 coffee crop with high productivity having its collected foliar samples in the summer and, 18 coffee crop with made foliar sampling in the winter with high productivity. To compare the established norms, test "t" of Student was used. It had differences of the relations of nutrients, enters the two times of sampling in the following relations: N/Fe, P/Ca, P/Fe, P/Zn, P/Fe, P/Mn, P/Ca, Ca/S, Mg/Fe, S/Fe, S/Zn, Fe/N, Fe/P, Fe/S and Zn/S 1%, N/Ca, N/Mn, N/Zn, P/Mg, P/Mn, K/S, Ca/N, Ca/Fe, Mg/P, Mg/S, Mg/Mn, S/Ca, S/Mn, B/P, Fe/K, Fe/B, Mn/N, Mn/P, Mn/S and Zn/N 5% and P/K, K/P, P/Ca, K/Zn, Ca/K, Ca/Mn, B/N, B/S, Cu/Fe, Cu/Mn, Fe/Ca, Fe/Mg, Mn/K, Zn/Fe, Zn/Mn 10%, allowing to affirm that it has differences between the two norms, indicating that these, besides being region, they must be specific for each time of the year (summer and winter).