The limited volume of substrate might reduce tuber multiplication rates when production is carried out in pots. The results of potato seed tubers multiplication in pots are presented in this publication, taking into account different plant densities and harvest methods. Experiments were carried out in an aphid-proof screenhouse, with 3 L pots, using virus-free seedlings previously acclimatized. In the first experiment, cultivars Monalisa and Agata, and two harvest systems were evaluated (single destructive and sequential 30-day intervals non-destructive harvests) in two seasons, namely spring/summer and autumn/winter. The experimental design was completely randomized, in a 2 x 2 factorial scheme, with six replications, four-pot plots and one seedling per pot. In the second experiment, potato seedlings from cultivar Monalisa were transplanted to pots according to the density treatments, from 1 to 5 seedlings per pot (25 to 125 plants m-2). The experiment was carried out in a completely randomized design with four replications and four-pot plots. Larger tuber yield per plant was obtained under non-destructive harvest for both cultivars. Instead, larger tuber length and fresh weight were observed in the single destructive harvest. Cultivar Agata outyielded cultivar Monalisa in number of tubers, although the latter produced longer and heavier tubers. Regarding plant density, each additional plant per pot (0.04 m² per plant), yielded 2.69 extra tubers per plant) (67.25 tubers m-2) in the spring/summer experiment and 4.36 extra tubers (109 tubers m-2) in the winter experiment. Nevertheless, the increase in density led to an average decrease of 3.20 g in tuber fresh weight per additional plant. In the spring/summer experiment, plant density had no significant influence on tuber fresh weight.
Solanum tuberosum L.; potato seed tuber; number of plants per pot; non-destructive harvest
