Estudos sôbre a alimentação mineral do cafeeiro: XXVI. efeitos de deficiências múltiplas no aspecto, crescimento e composição mineral (nota preliminar)

Abstract

Young coffee plants were grown in nutrient solution from which the following elements were omitted, singly or in several combinations: nitrogen, potassium, boron and zinc. The choice of these elements was basee on the high frequency of occurrence of their deficiencies under field conditions in Brazil. The effect of single or multiple deficiencies was studied under several aspects, namely: growth, visual symptons, mineral composition. The following conclusions can be drawn: (1) symptons of deficiency of nitrogen, potassium, boron and zinc can be identified even when occurring simultaneously; (2) the concentration of nitrogen, potassium, boron and zinc is markedly influenced by their supply in the substrate, as well as by the concentration of other elements in the medium; (3) cases of multiple deficiency should be taken into consideration when interpreting results of leaf analysis.