Information regarding cultivars adapted to the organic system of production is scarce. The aim of this study was to evaluate in an organic production system, Brazilian and foreign potato genotypes adapted for conventional systems, in terms of quality and yield potential. The experiment was carried out in 2008, at the Agro-ecological Experimental Station of the Polo APTA Leste Paulista, in Monte Alegre do Sul, São Paulo State, Brazil. A randomized block experimental design was adopted with 18 treatments and four replications. Each plot consisted of 80 seeds, arranged in four rows of 5 m spaced 0.80 m and with 0.25 m between tubers. The treatments consisted of the cultivars Agata, Apuã, Aracy, Asterix, Caesar, Catucha, Cupido, Éden, IAC Aracy Ruiva, Itararé, Melody, Monte Alegre 172, Novella, and Vivaldi, in addition to the advanced clones IAC 6090, APTA 16.5, APTA 15.20 and APTA 21.54. The following parameters were evaluated: yield, marketable yield, average total and marketable tuber mass, dry matter content and severity of potato early blight. The advanced clones APTA 16.5, APTA 21.54, IAC 6090, and the cultivars Cupido, Apuã, Itararé and Monte Alegre 172 showed the highest yield values. 'APTA 21.54' presente the highest marketable yield (18.07 t ha-1), whereas 'APTA 16.5', 'Cupido', 'IAC 6090' and 'Itararé' formed the subsequent group. The highest tuber mass values were presented by the cultivars Itararé and Cupido. The clone IAC 6090 and the cultivars Aracy and Aracy Ruiva showed the highest dry matter content, with an average of 22.91%. 'APTA 16.5', 'Apuã', 'Aracy', 'Aracy Ruiva', 'Éden', 'Ibituaçú' and 'Monte Alegre 172' exhibited high level of field tolerance to early blight. Potato genotypes Itararé, Apuã and Cupido are, thus, adapted to organic farming, and the advanced clones APTA 16.5, APTA 21.54 and IAC 6090 have potential for cultivation in the organic system.
Solanum tuberosum; Alternaria solani; agroecology; organic olericulture; sustainable crop systems
