Sistema integrado de diagnose e recomendação (DRIS) na avaliação do estado nutricional da cultura do coqueiro hibrido

Abstract

Among the methods used for the interpretation of the results of foliar analysis, there is the integrated system of diagnosis and recommendation (DRIS). This method is based on the caleulation of an index for each nutrient. For the calceulation of DRIS norms, there is a need to organize a database of foliar orchards with known productivity, and establish standards for the relationships between nutrients. In the Amazonian conditions, specifically in the state of Pará, no DRIS norms developed for hybrid coconut culture. Hus the aim of this work was to develop DRIS norms for different selection criteria of the relationships between nutrients for growing the hybrid coconut in Pará. The study was conducted in the municipality of Farm SOCOCO Moju PA. Was used to form the database results of leaf analysis and productivity of 134 observations for the period 2001-2011. Obtained the mean, standard deviation, coefficient of variation and variance of the relationships of the nutrients, the leaf samples of vintages from 2001 to 2011, the coefficient of correlation between the ratio of each pair of nutrients and fruit yield. The highest values of standard deviation, variance and coefficient of variation were presented for foliar concentrations of the micronutrients iron, manganese and boron. The nutrients showed higher percentages of samples with levels below the appropriate levels used were Mg and Ca, while nutrients showed that samples with foliar concentrations above or equal to the appropriate levels were Fe, Mn and Ca. DRIS norms for growing hybrid greens were established, based on the relationships between nutrients in the population of high productivity. Of the 110 relationships between nutrients studied, 55 relationships were selected to compose the DRIS norms for the cultivation of hybrid coconut, using two selection criteria of the relationships between nutrients.

The assessment of the nutritional status of plants by leaf analysis as the Integrated System Diagnosis and Recommendation (DRIS) has been highlighting the traditional methods of interpreting the results of the analysis of plant tissue. From the DRIS indices expressing the balance of nutrients in a plant, comparing relationships in the sample being diagnosed with rules or default values are calculated. For the coconut, nutritional counseling through foliar analysis is touted as an efficient method for fertilizer recommendation, and the results have been traditionally interpreted using the criteria and the critical level of sufficiency ranges. The objective of this study was to evaluate the nutritional status and establish nutritional standards for the cultivation of hybrid coconut in the municipality of Moju, Pará, using the DRIS. Was used to form the database results of leaf analysis and productivity of 134 observations for the period 2001-2011. To calculate DRIS indices of 134 leaf samples were used DRIS norms established in the first chapter of this work. It was found for the most common deficiencies element K, and Mg possibly in excess element. The order of nutrient limitation, was K> P>Ca> Fe> N> O> B> Zn> Cu> Mn> Mg. The Ca, Fe and K nutrients are more likely to respond positively to fertilization, since the Mg, Cu and Mn nutrients, were diagnosed as having the greatest like lihood of negative response to fertilization. It was also found that N and P are the ones that are in the best position to nutritional balance. Regression equations for the relationship between the nutrient content in leaves of hybrid coconut and its DRIS indices, which allowed establishing nutrient reference values, based on DRIS were adjusted.

The DRIS method has been used infrequently as a tool for evaluating theresults of fertilization experiments in different crops. Watts work has shown that the method has been able to identify nutritional limitations with different culture, thus confirming its robustness and efficiency in nutritional diagnostics. The aim of this study carry the nutritional diagnosis of the culture of hybrid coconut, from the use of the critical level method and the integrated system of diagnosis and recommendation (DRIS) on the results of experiment evaluating different sources of phosphorus. Nutritional diagnostics for macro and micronutrients were drawn from critical levels (CL) and integrated system of diagnosis and recommendation (DRIS), with results obtained from the experiment of phosphorus fertilization on crops in 2004, 2005, 2006 and 2007 data and productivity levels leaf were used from this experiment in the area of commercial coconut production company Socôco - Agribusiness Amazon. There was no significant response to the productivity variables assessed in any of the four years evaluated. Despite the absence of significant effects, it was found that the treatments resulted in different values of productivity. It was found that the nutritional diagnostic prepared from the DRIS method of predicting were consistent fills or nutritional deficiencies for P element, depending on the treatments to different sources and combinations, since with reference to the traditional method of interpreting through the level critical leaf, there was agreement in the nutritional information for P.