Índices diagnósticos para interpretação de análise foliar do milho

Abstract

R E S U M OA diagnose foliar é o método de maior relevância na definição e na interpretação do estado nutricional das plantas. A interpretação correta sobre o estado nutricional da cultura só é possível quando se regionalizam os valores de referência. Objetivou-se, com este trabalho, determinar índices diagnósticos para interpretação de resultados de análise foliar de milho mediante o uso dos métodos de interpretação: Nível crítico (NC), Faixa de suficiência (FS) e Índices Balanceados de Kenworthy (IBK). Amostraram-se solos, folhas e produtividade em 120 lavouras de milho, nas safras agrícolas 2010/2011 e 2011/2012, na região do Alto Paranaíba, MG. Para gerar os índices diagnósticos pelos métodos FS e IBK a população foi dividida em duas subpopulações, com base na produtividade: acima ou abaixo de 11.795 kg ha -1 . Os teores de nutrientes propostos como adequados pelos métodos citados foram semelhantes. A amplitude das faixas ótimas foi menor que a encontrada na literatura para milho. Os índices diagnósticos regionalizados pelos métodos NC, FS e IBK aumentam a confiabilidade ao diagnosticar talhões com as mesmas características das normas estabelecidas em relação a valores de referência universal. Diagnostic index for interpretation of foliar analysis of corn A B S T R A C TAt present, the leaf analysis is the method of greatest relevance in the definition and interpretation of nutritional status of plants. The correct interpretation of the nutritional status of the crop is only possible when it regionalizes reference values (standards). This study aimed to determine reference values for the interpretation of the results of leaf analysis of maize through the use of methods of interpretation: critical levels (CL), sufficiency range (SR) and balanced indexes of Kenworthy (BIK). Sampling of soil, leaves and productivity was conducted in 120 commercial crops of corn, in the crop year of 2010/2011 and 2011/2012, in the region of Alto Paranaíba, MG. To generate the diagnostic indexes by the methods SR and BIK, the population was divided into two sub-populations: with the productivity above and below 11,795 kg ha -1 . Levels and normal ranges proposed by the cited methods were very similar. The amplitude of optimum ranges were lower when compared to that one found in the literature. The diagnostic indexes regionalized by the methods CL, SR and BIK increased the reliability when diagnosing plots with the same characteristics of the standards approved in relation to universal reference values. Palavras-chave:Zea mays L. nível crítico equilíbrio nutricional

DRIS indices in three phenological stages of the carrot crop

“…The Diagnosis and Recommendation Integrated System (DRIS) method was developed by Beaufills (1973) and has been used to interpret results of foliar analysis in several crops (Gott et al 2014, Dezordi et al 2016. It considers the dual relationship between nutrients, and not only the single contents in plant tissues, with advantages regarding simpler methods, such as the Critical Level and the Sufficiency Range (Gott et al 2014).…”

“…It considers the dual relationship between nutrients, and not only the single contents in plant tissues, with advantages regarding simpler methods, such as the Critical Level and the Sufficiency Range (Gott et al 2014). A major advantage of the method is to minimize the dilution and concentration effects, because it is based on the nutrients balance (Beaufils 1973, Jones 1981.…”

Diagnostic Methods to Assess the Nutritional Status of the Carrot Crop

“…The interval composing the classes was obtained by dividing the total amplitude of the nutrient by the number of classes. Subsequently, linear mathematical models were fitted to study the relationship between the leaf content of each nutrient and the yield of the 14 classes, as performed by Gott et al (2014). Each nutrient was evaluated separately from others.…”

“…The methods most used for interpretation of leaf analysis have been Critical Level (CL), Sufficiency Range (SR), Diagnosis and Recommendation Integrated System (DRIS), and Compositional Nutrient Diagnosis (CND) (Coelho et al, 2013;Gott et al, 2014). The CL method consists of mathematical models to establish the leaf nutrient contents that allow production of a certain fraction (90, 95, or 99 %) of maximum yield.…”

Boundary Line Model to Estimate the Nutrient Sufficiency Range in Muskmelon Leaves

“…Similarly to the method proposed by Maia et al (2001) to calculate critical leaf concentrations and the method that uses the mean and standard deviation of the nutrient in a high-yielding population to establish the sufficient range (Gott et al, 2014), the boundary line is an alternative to compute the critical level and leaf sufficiency range without requiring field trials, but only nutritional status data.…”