Effect of the nitrogen, phosphorus and potassium fertilization on the potato tuber yield

This work was carried out in aAo Joaquim, Santa Catarina State, Brazil, in two cultivation cycles (1999/00 and 2001/02), to evaluate the effect of the nitrogen, phosphorus and potassium fertilization on the tuber yield of potato-seed. The experiment had a randomized block design with four replicates. Three levels of N and K2O (0; 150 and 300 kg ha(-1)) and four rates of P2O5 (0; 350; 700 and 1050 kg; ha(-1)) were tested. The tuber production was affected by the nitrogen and phosphorus fertilization and, depending on the cultivation cycle, also by the potassium one. The yield was increased by P2O5 rates from 694 to 920 kg ha(-1) depending on the cultivation cycle and nitrogen rates. These amounts were higher than those recommended by the official institution for Santa Catarina and Rio Grande do Sul States.