Methods of drying leaf samples of barbados cherry sugar cane and citrus for determination of dry matter and macronutrients contents | Métodos de secagem de amostras de folhas de aceroleira, cana-de-açúcar e citros na determinação da massa seca e nos teores de macronutrientes

English. The drying of leaf samples with use of a microwave oven can be a viable alternative for obtaining rapid results of leaf analysis. The objective of this paper was to compare the drying process in FMO and greenhouse forced air ventilation in the determination of dry matter and macronutrient leaf crops of citrus, sugar cane and barbados cherry. The treatments consisted of two drying methods, an air forced circulation greenhouse regulated to a temperature of 700C and FMO, in which each sample was subjected to drying in 3 cycles of 5 minutes, 1 cycle of 3 minutes, 1 cycle 2 minutes and 1 cycle of 1 minute, reaching constant weight. The experiment was a hierarchical arrangement 2 x 3 (two drying methods and three species), with six replicates. Using the method of FMO drying and the air forced circulation greenhouse did not influence the dry weight and macronutrient content of leaves of the crops of citrus, barbados cherry and sugar cane, indicating that the use of FMO is a viable alternative to be used in laboratories of foliar analysis.

Portuguese. A secagem de amostras foliares com emprego do forno de micro-ondas pode ser uma alternativaviável para obtenção rápida dos resultados da análise foliar. Objetivou-se avaliar métodos desecagem em forno de micro-ondas (FMO) e em estufa de ventilação de ar forçada de amostrasfoliares das culturas de citros, aceroleira e cana-de-açúcar, a partir da determinação da massaseca e dos teores de macronutrientes. Os tratamentos constituíram-se por dois métodos desecagem, estufa de circulação de ar forçada regulada a uma temperatura de 700C e o FMO,em que cada amostra foi submetida à secagem em 3 ciclos de 5 minutos, 1 ciclo de 3 minutos, 1ciclo de 2 minutos e 1 ciclo de 1 minuto, atingindo massa constante. O delineamento experimentalutilizado foi um arranjo hierárquico 2x3 (2 métodos de secagem e 3 espécies), com 6 repetições. Ouso do método de secagem FMO e da estufa com circulação de ar forçada não influenciaram amassa seca e os teores de macronutrientes de amostras de folhas das culturas de citros, aceroleirae cana-de-açúcar, indicando que o uso do FMO é uma alternativa viável para uso em laboratóriosde análise foliar. Methods of drying leaf samples of barbados cherry sugar cane and citrus fordetermination of dry matter and macronutrients contentsAbstractThe drying of leaf samples with use of a microwave oven can be a viable alternative for obtainingrapid results of leaf analysis. The objective of this paper was to compare the drying process in FMOand greenhouse forced air ventilation in the determination of dry matter and macronutrient leafcrops of citrus, sugar cane and barbados cherry. The treatments consisted of two drying methods,an air forced circulation greenhouse regulated to a temperature of 700C and FMO, in which eachsample was subjected to drying in 3 cycles of 5 minutes, 1 cycle of 3 minutes, 1 cycle 2 minutes and1 cycle of 1 minute, reaching constant weight. The experiment was a hierarchical arrangement 2 x3 (two drying methods and three species), with six replicates. Using the method of FMO drying andthe air forced circulation greenhouse did not influence the dry weight and macronutrient contentof leaves of the crops of citrus, barbados cherry and sugar cane, indicating that the use of FMO is aviable alternative to be used in laboratories of foliar analysis.