ESTABLISHMENT OF DRIS NORMS FOR GROWING HYBRID COCONUT IN PARÁ

Abstract

The Integrated Diagnosis and Recommendation (DRIS) is based on the calculation of an index for each nutrient. For the calculation of DRIS norms, there is a need a database containing the results of leaf analysis and yield. In Pará State, no DRIS norms developed for the cultivation of hybrid coconut. The objective was to develop DRIS norms for this culture. The aim was carried at the Socôco farm in Moju PA. The database consisted of 134 observations for the period 2001-2011. We obtained the mean, standard deviation, variance and coefficient of variation of the relationships of concentrations of nutrients, and the coefficients of correlation between the ratio of each pair of nutrients and fruit yield. DRIS norms were established based on the population of high productivity. Of the 110 relationships, 55 were selected to DRIS norms, using two selection criteria of relationships between nutrients. The highest values of standard deviation, variance and coefficient of variation were presented to the leaf levels of the micronutrients iron, manganese, and boron. While the nutrients showed higher percentages of samples with levels below the adequate levels used were Mg and Ca, and finally the nutrients in leaf samples presented above or equal to the adequate levels contents were Fe, Mn and Ca.