The consequences of the depletion of P resources and P-fixation in acidic soils have aroused interest in recent years to make more study basing on its behaviour in different varieties of Robusta coffee as a means to manage its use efficiency. This study aimed at characterizing the four varieties of Coffea canephora regarding their capacities of phosphorus absorption, translocation and usage, an important concept to the investigation of varieties with potential to adapt to limited soil P. A screen house pot experiment was conducted in a Completely Randomized Design in a 3x4 factorial scheme with three rates of P as TSP fertilizer. Factors were three rates of P (0, 37.5, 75mg/kg) and four varieties of Coffea canephora (BK27, MR10, ML2, 13/61). Phosphorus efficiency indices (absorption efficiency, translocation efficiency and use efficiency) were calculated by the respective formulas in spread sheet and the raw data were run by using Genstat software 14th edition. Pair wise means separated by using Fisher’s protected and the results revealed the differential behaviour of Phosphorus in terms of translocation efficiency and use efficiency (p < 0.05) in different varieties at different rates. But for the absorption efficiency no statistical significance observed. This study then tried to show that varieties differ on their efficiencies for P depending the distribution and availability of P within the soil.
Key words: Phosphorus efficiencies, coffea canephora