The 2011 ASHS Annual Conference

Commercial sugar beet (Beta vulgaris var.) production for sugar takes place predominantly in temperate regions; however, recently-developed tropical sugar beet (TSB) varieties constitute a specialty item that can be grown in tropical and subtropical regions as a feedstock crop for biofuel (bioethanol) production. Field investigations were conducted between 2008-2010 near Weslaco, Hidalgo Co, TX to verify, and to estimate productivity, root quality, and susceptibility to bolting potential of tropical sugar beet (TSB) varieties under sub-tropical conditions. None of the seventeen varieties evaluated bolted during the study period.  Estimates of root yield (~20 tons/acre) and root sugar concentrations (12-19%) were within the range of values commonly reported in temperate production regions.  Significant differences in leaf and canopy morphology and development patterns were observed among the varieties; however, effects probably due to timing of planting masked differences in yield and quality among the varieties.  Differences among genotypes in yield estimates and sugar content were generally minimal; however, genotypes with the planophile-type foliage had slightly higher sugar contents than the erectophile genotypes, perhaps due to greater radiation interception and CO₂ assimilation. These results demonstrate that tropical sugar beets can be grown profitably in subtropical climate conditions with yields similar to those commonly realized in temperate commercial production regions. The data suggest that higher-than-average yields are possible when optimal planting dates and other cultural practices are developed and implemented. TSB varieties could serve as a rotational crop to supplement the sorghum/sugar cane-based bioenergy feedstock supply chains.  Because the TSB production season is typically short (5-6 months), the potential for high yields is great in the subtropical climate conditions.