Sugarcane (Saccharum spp.) is harvested during a 5-month period (October to March) in south Florida. "Early maturing" cultivars milled in October or November may not have reached their peak sucrose content, but may have higher sugar per ton (SPT, lbs sucrose/ton of sugarcane biomass) than other cultivars at the onset of milling operations (Miller and James 1977). Under current industry milling capacities, harvesting the 375, 642 acres of Florida sugarcane (VanWeelden et al. 2019) takes roughly 5 months. Unavoidably, sugarcane plants harvested during the early harvest period have not yet achieved maximum sugar content. Consequently, sugar content for any given cultivar will change over the course of the harvest season, which can impact the profitability of the harvest. Maturity curves of SPT vs. time have been developed for sugarcane cultivars in South Africa (Bond 1982), Louisiana (Legendre and Fanguy 1975; Legendre 1985; Richard et al. 1981) and Mauritius (Mamet and Galwey 1999). Although it is known that sucrose accumulation rates vary between varieties, maturity curves for recently released "CP" sugarcane cultivars (those developed at the USDA-ARS Sugarcane Field Station in Canal Point, FL) have not been reported since 1977 (Rice, 1974; Miller and James 1977). CP cultivars occupy > 90% of Florida sugarcane acreage, and are also economically important (Tew 2003) in many countries including Argentina (25% of total acreage), Belize (16%), El Salvador (50%), Guatemala (65%), Honduras (47%), Mexico (15%), Morocco (54%), Nicaragua (75%), Senegal (9%) and Venezuela (9%). Since most sugarcane growers in Florida plant a diverse selection of cultivars, these maturity curves are needed as tools to help growers make informed choices regarding harvest scheduling decisions.
This fact sheet presents the sucrose accumulation maturity curves for different crop ages (plant cane, 1st ratoon, and 2nd ratoon) of CP 89-2143. CP 89-2143 harvest samples were collected at 2-week intervals at 5 locations over 4 harvest seasons in the Everglades Agricultural Area. Biomass and sugar yields were determined on all samples in order to generate SPT trends over time. A full comparison of CP 89-2143 SPT trends with 12 other CP cultivars may be found in EDIS publication SS-AGR-221, Maturity Curves and Harvest Schedule Recommendations for CP Sugarcane Varieties https://edis.ifas.ufl.edu/sc069.
CP 89-2143 has been recently phased out from the EAA sugarcane acreage in Florida due to orange rust susceptibility (VanWeelden et al. 2019). However, CP 89-2143 is currently grown on significant area in Texas as a principal cultivar and expanding in both Texas and Louisiana due to less orange rust pressure in these states. This cultivar has shown remarkably high sugar content and better than average tonnage and freeze tolerance. Descriptive information and photographs of CP 89-2143 can be found at https://edis.ifas.ufl.edu/ag137.
Figure 1 presents the sugar per ton (SPT, lbs sugar/ton sugarcane biomass) for CP 89-2143 from mid-October to mid-March. Separate curves are presented for plant cane, 1st ratoon, 2nd ratoon, and the entire data set.
Research has shown that older ratoon crops generally have higher SPT values but lower tonnage (Glaz et al. 1989; MacColl 1976). Thus, growers should generally expect the SPT of their sugarcane crop to increase with crop age (see Figure 1). However, the mean SPT of CP 89-2143 remained relatively stable across crop ages, averaging 283 lbs/ton in plant cane, 284 lbs/ton in 1st ratoon, and 277 lbs/ton in 2nd ratoon. The overall mean across crop ages ranked 1st out of 13 CP cultivars.
Grower recommendations are based on the entire data set across all crop ages. Early-season predicted SPT for CP 89-2143 at the onset of harvest on October 14 was 223 lbs/ton (ranked 1st out of 13 cultivars), and maximum predicted SPT was 308 lbs/ton on February 11 (ranked 1st out of 13 cultivars). In comparison to other CP cultivars, CP 89-2143 has excellent sucrose content throughout the harvest season. Due to its excellent post-freeze characteristics it should be reserved for harvest during the last 50 days of the harvest season (see https://edis.ifas.ufl.edu/sc069).
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Gilbert, R.A., J.M. Shine, Jr., J.D. Miller and R.W. Rice. 2004. Sucrose accumulation and harvest schedule recommendations for CP sugarcane varieties. SS-AGR-221. Gainesville: University of Florida Institute of Food and Agricultural Sciences. https://edis.ifas.ufl.edu/sc069.
Glaz, B., M.F. Ulloa and R. Parrado. 1989. "Cultivation, cultivar and crop age effects on sugarcane". Agron. J. 81:163–167. https://doi.org/10.2134/agronj1989.00021962008100020005x
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Schueneman, T.J., J.D. Miller, R.A. Gilbert and N.L. Harrison. 2001. Sugarcane cultivar CP 89-2143 descriptive fact sheet. SS-AGR-122. Gainesville: University of Florida Institute of Food and Agricultural Sciences. https://edis.ifas.ufl.edu/ag137.
Tew, T.L. 2003. "World sugarcane variety census – year 2000". Sugar Cane International March/April 2003:12–18.
VanWeelden, M. T., S. Swanson, W. Davidson, M. Baltazar and R. Rice. 2019. "Sugarcane variety census: Florida 2018". Sugar Journal. 82(2): 12–19.