Physiological characterization of plant growth in sweet potato

ABSTRACT This research was installed to study plant growth of sweet potato and identify the most favorable harvest time for both roots and the aboveground part (stems). The experiment was carried out at the JK campus of the Federal University of the Vale do Jequitinhonha e Mucuri, in Diamantina, MG, complete blocks at random, with four replications. Three plants in the central part of the experimental plots were collected in twelve consecutive harvests at 15-day intervals. Plants were fractionated in roots, stems, and leaves to determine the dry matter of each part. Leaf area was also measured and growth rates were calculated. Data were analyzed by means of regression. Plants reached the highest dry matter accumulation between 75 and 156 days after transplanting (DAT), which corresponded to the phase of greatest growth. Plants should be harvested between 60 and 87 DAT to achieve the highest stem yield. For the highest root yield, the harvest should be carried out 180 DAT. The period from 80 to 118 DAT was the most adequate for reaching simultaneously the highest yields for both roots and stems. Therefore, the ideal harvest time for sweet potatoes depends on the use intended for the plant and on the physiological indexes associated with it.