Use of P for Three Potato Clones in Soil and in Soilless Cultivation

The objective of this work was to verify the nutritional efficiency to phosphorus (P) as well as the responses of the use of P for three potato clones in soil and soilless cultivation (semi hydroponic). For this purpose, the Asterix, SMIC 148-A and SMINIA 793101-3 clones were evaluated under high and low P levels in soil growing (70 and 560kg P2O5 ha-1) and in soilless cultivation using sand as substrate (2.32 and 23.2mg P L-1 of nutritive solution). Rooting efficiency, absorption, translocation and use of P, fresh tuber mass, total dry mass and harvest index were evaluated in the clones. Each clone responds differently to the growing systems used in terms of nutritional efficiency for P. In both growing systems, the Asterix, SMIC 148-A and SMINIA 793101-3 clones did not show any increase in the absorption efficiency and in the efficiency of using P to compensate for the low level of P, which may have caused the reduction in total dry mass under low P. The restriction of P causes a reduction in tuber fresh mass for the Asterix and SMINIA 793101-3 clones in the two growing systems tested and for the SMIC 148-A clone only in soilless cultivation. Asterix is the clone with the highest harvest index under low P in the field, even without differing from the others in soilless cultivation