Identification of morphoagronomic traits correlated with the N use efficiency in coffee

Abstract

The study of nutritional efficiency is an expensive process, as it requires extensive planting areas, several years of evaluation and the destruction of plants. To mitigate these difficulties, a strategy would be to identify easily measurable traits associated with nutritional efficiency in growing a nutritional solution. Thus, the objective of this study was identify morphoagronomic traits correlated with the N-efficiency indices in to assist in selecting coffee genotypes for environments with N restriction. Twenty arabica coffee genotypes were grown in a nutrient solution with a low concentration of nitrogen (1.0 mmol L-1). The experiment was conducted in a randomized block design with three replications. There was variability among the coffee genotypes for all the traits evaluated. Most of the traits evaluated showed greater genetic than environmental influence on phenotypic expression. Heritability (H2) was greater than 70% for most of the traits evaluated, with an emphasis on plant height and internode length, which also had the highest relative variation indices (RVIs). The associations between morphoagronomic traits and nutritional efficiency indices revealed greater contributions of genotypic correlation than of environmental correlation. Among the traits associated with nutritional efficiency indices, stem diameter has the potential for use in breeding programs for the selection of cultivars that present greater nitrogen efficiency in environments with nitrogen restriction.