Differential tolerance between genotypes of conilon coffee ('Coffea canephora') to low availability of nitrogen in the soil

Aspects related to mineral nutrition are gaining space and importance in breeding programs and in studies related to the behavior of coffee genotypes. Therefore, the objective of this study was to evaluate the differential tolerance between genotypes of conilon coffee subjected to low availability of nitrogen in the soil, as well as the gains obtained with the addition of this nutrient in the soil through fertilization. Ten genotypes of Coffea canephora were cultivated in greenhouse, without fertilization with N and with fertilization at level of 0.625 g kg-1 of soil, tested in a completely randomized design. Based on the results of growth analysis and expression of variability between genotypes, the most appropriate level was selected to discriminate the genotypes for tolerance to low availability of nitrogen in the soil. Following this premise, the genotypes 67, 23 and 02 were classified as intolerant and the genotypes 32, 73, 83, 77, 76, 24 and 153 as tolerant to low availability of nitrogen in the soil. It was also noticed an increased plant growth with nitrogen fertilization and, as consequence, greater biomass accumulation, as well as better development of leaves, in quantity, area and content of photosynthetic pigments. The pattern of biomass allocation between the plant compartments were also altered, favoring leaves and stems.