Optimizing Planting, Harvesting, and Pest Management Practices for Energybeet Production in South Florida.

Sugar feedstocks such as energybeet (Beta vulgaris L.) are easy to convert and efficient for bioenergy production. Management practices including planting and harvest date and pest management can affect total biomass production and sugar yield, but relatively few data are available for energybeet grown on organic soils in south Florida. Field experiments were conducted during 2013-14 (Y1) and 2014-15 (Y2) growing seasons on organic soil at Belle Glade, FL to compare the effect of planting and harvest dates and pest management on biomass and sugar yield of energybeet. Energybeet varieties were planted at three times (October, November, and December) and harvested at four times (March, April, May, and June), under both pesticide sprayed and non-sprayed conditions with four replications per treatment. Delayed planting resulted in decrease in root fraction and increase in leaf fraction during both years of the study. October planting resulted in 17 and 68% increase in sugar yield in Y1 and 34 and 79% increase in Y2 compared to November and December planting, respectively. Delay in harvest from March to June resulted in increase in root fraction and decrease in leaf fraction. Root yield increased with delay in harvesting until June during Y1, however juice brix declined late in season resulting in greatest sugar yield in May during both seasons. Energybeet varieties did not differ in total sugar yield. Pesticide application resulted in significant root and sugar yield increase only under early planting (October) during both years and late harvest (May and June) in the first year. Overall, root and sugar yield of 65-74 and 7.2-8.5 Mg ha^-1, respectively were observed under early planting and late harvest in this study. Results indicated that energybeet can be grown as a rotational crop with sugarcane to produce high sugar yield on organic soil in south Florida.