<p></p><p>ABSTRACT The cultivar selection is fundamental to reach high potato yield in the organic production system. The objective of this work was to evaluate tuber yield and yield components and make suggestion for organic production system in South region of Brazil. The experiment was carried out in two crop seasons, 2013/2014 and 2014/2015, three trials, in Guarapuava, Paraná State and Caseiros, Rio Grande do Sul State, Brazil. Eight cultivars were evaluated (Agata, Clara, Eliza, Catucha, Aracy Ruiva, Itararé, Vitória and Cris) for total and marketable tuber yield, number of total and marketable tubers, and percentage of tuber dry matter content. A completely randomized block design in a split plot scheme, with trials as main plot and cultivars in sub plot, and four replications was used. The total and marketable yield varied according to the trial, however ‘Catucha’ stayed always in the group of high yielding cultivars, reaching around 28 and 23 t/ha of total and marketable yield, respectively. The relatively high yield of this cultivar was mainly due to high number of tubers, around eight and four/plant, total and marketable tubers, respectively. Moreover, this cultivar had the tubers with higher percentage of tuber dry matter content in all three trials (25; 16 and 21% in the trials 1; 2 and 3, respectively). Therefore, ‘Catucha’ is one of the suggested cultivars for the organic potato system in region of subtropical climate in Brazil.</p><p></p
