Sweet potato is a crop with a wide morpho-agronomic variation among genotypes. Source-sink relationship is determined by the regulation capacity of heterotrophic and autotrophic organs. To understand the influence of morphological traits, biomass allocation, and plant growth on sub-humid adaptation, eighteen genotypes were morpho-agronomically characterized under three texture soils (Cerete, Carmen de Bolivar, and Corozal). Subsequently, selected genotypes were evaluated to determine growth rates and, source and demand potential. Morphological features seem to significantly influence the agronomic performance of sweet potato genotypes, especially those related to leaf description and plant architecture. Efficiency of cover ground was a determinant trait for sweet potato yield, but, it was not completely related to above-ground biomass yield. Through growth rate analysis and morphological features description, the negative influence of excessive accumulation of foliar biomass on production of storage roots of sweet potato was confirmed. In soils with low water holding capacity, the genotypes with higher cover ground efficiency at establishment phase showed major adaptation and root biomass accumulation. Morpho-physiological evaluation of sweet potato genotypes could be considered as a helpful strategy to improve varietal selection with tolerance to limited water availability.