Resumen en Inglés:

Several trials were conducted with potatoes (Solanum tuberosum L.) to study the relative value of the apical and basal sets, as compared to whole seed tubers, since cutting potatoes before planting has been a matter of discussion. The experiments have been carried out on a high and on a low districts, say, respectively, at Joanópolis mountainous region, and at Taubaté flat lands, the latter on the right bank of Paraíba river, both in the State of São Paulo. Results have shown that on high lands, over 1,000 meters above sea level, the cutting process may be accomplished, though the basal sets have yielded less than apical ones, and whole tubers. Apical sets produced as well as whole tubers. At Taubaté district, aproximately 500 meters above sea level, where potato crop is usually grown from May to September in the dry season, on irrigated flat lands, after rice has been harvested, best results were secured from whole seed tubers. Apical and basal sets decayed easily, due probably to irrigation water ; for this reason they are not to be used.