The objective of this work was to evaluate yield capacity of Comum tannia (Xanthosoma mafaffa Schott) from secondary seed-rhizomes of different sizes and cultivated under three or four rows of plants per plot. Treatments were established by the combination of the number of rows of plants per plot and by the planting of four sizes of secondary seed-rhizomes (fresh mass, in gram, and diameter, in millimeter, respectively, of T1 = 2.96 and 8.77; T2 = 1.33 and 6.05; T3 = 1.13 and 5.68 and T4 = 0.78 and 4.83, average of 300 rhizomes of each size), as 2 x 4 factorial scheme in a randomized block experimental design with four replications. Harvest was done on 300 days after planting. Yields of fresh mass of rhizomes, total, corms and cormels were influenced significantly by number of rows per plot/size of seed-rhizomes interaction. Average of diameters, lengths and fresh masses of corms (43.13 mm; 21.36 mm and 13.21g) and cormels, from big (37.15mm; 18.57 mm and 9.60 g), medium (30.71 mm; 14.18 mm and 4.14 g) and small (19.72 mm; 9.46 mm and 1.07 g) classes, showed variations significantly which were dependent on number of rows per plot/size of seed-rhizome interaction, inside each evaluated characteristic of rhizomes. The highest total yields (11.48 t ha-1) and commercial rhizomes (4.51 t ha-1) were from the treatment with three rows of plants and T1 seed-rhizome and the highest yields of non-commercial rhizomes were from the treatment with four rows of plants and T2 seed-rhizome (7.41 t ha-1). The most low total yields (0.96 t ha-1), net (0.86 t ha-1), commercial (0.60 t ha-1) and of non-commercial (0.26 t ha-1) were from the treatment with three rows of plants and the planting of T4 rhizomes.
Xanthosoma mafaffa; propagules; productivity
