Genetic variability of conilon coffees regarding growth efficiency for nitrogen in intercropping with dwarf coconut

The objective of this study was to quantify growth efficiency parameters of genotypes of conilon coffee cultivated in intercropping with dwarf coconut, in order to verify the suitability of nutritional parameters to cluster genotypes and aid possible selections to improve efficiency traits. The experiment was developed in a consortium system, following a completely randomized design, testing eight genotypes of conilon coffee (Coffea canephora) randomly distributed along the lines of consortium with dwarf coconut trees (Cocos nucifera), using six replications. Nine parameters of growth efficiency were used, based on the conversion rate of nitrogen in leaves (main sources) to number, size and mass of other plant structures. The results showed that using growth efficiency parameters is adequate to study the variability and to cluster genotypes in groups of different levels of efficiencies. Some parameters seem to be more suitable to quantify the growth efficiency for nitrogen, such as dry matter, number and combined lengths of leaves, the chlorophyll content, and the number of fruits. The phenotypic and genetic variability expressed, even in a restricted group of eight improved coffee genotypes, seems to be enough to allow a selection of genotypes more suitable for intercropping. Considering the evaluated conditions, the genotypes 16, 100, 76 and 153 stand out for this intercropping, as they could be selected to promote gains in several of the growth efficiency parameters for nitrogen.