Phosphate fertilization in potato: productivity of agata and Atlantic

The goal of this study was to evaluate the influence of phosphate rates on productivity of potatoes tubers of cultivars Atlantic and agata. The experiments were carried out in Unai-MG, Brazil (agata and Atlantic) and Mucuge-BA, Brazil (agata). The rates of phosphate was 0, 150, 300, 600 and 900 kg ha(-1) of P2O5. All macro and micronutrient contents increased by increasing P rates in Atlantic-MG. In agata-MG, only S was reduced and in agata-BA, higher rates of P reduced N, Cu, Mn and Zn contents. Despite this reduction, only Zn was below the range considered suitable for potato. The maximum rates estimated for total yield in Atlantic-MG (38 t ha(-1)), agata-MG (47.6 t ha(-1)) and agata-BA (59.7 t ha(-1)) were, respectively: 606, 730 and 535 kg ha(-1) of P2O5. The P response of agata-BA was 25.4% lower than agata-MG. This can be related to medium clay content and low CEC of Mucuge-BA soils, compared to Unai-MG soils, which are more clayey and have a higher CEC, consequently, they have a higher P retention capacity. However, rates of P should be oriented based on knowledge of soil attributes and dynamics of its constituents, cultivar requirements and interactions with regional climatic conditions.