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Publication #SS-AGR-214

Sucrose Accumulation Maturity Curves for CP 78-1628 1

Maninder P. Singh, Hardev S. Sandhu, Robert A. Gilbert, James M. Shine, Jr., and Ronald W. Rice2


Sugarcane (Saccharum spp.) is harvested during a five-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, lb of sucrose per ton of sugarcane biomass) than other cultivars at the onset of milling operations (Miller and James 1977). Under current industry milling capacities, harvesting the 425,000 acres of Florida sugarcane (Rice et al. 2013) takes roughly five 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, Florida, in collaboration with the University of Florida and the Florida Sugar Cane League) have not been reported since 1977 (Rice 1974; Miller and James 1977). CP cultivars occupy more than 80 percent of Florida sugarcane acreage (Rice et al. 2013) 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 publication presents the sucrose accumulation maturity curves for different crop ages (plant cane, first ratoon, and second ratoon) of CP 78-1628. CP 78-1628 harvest samples were collected at two-week intervals at five locations over four harvest seasons in the Everglades Agricultural Area (EAA). Biomass and sugar yields were determined on all samples in order to generate SPT trends over time. A full comparison of CP 78-1628 SPT trends with 12 other CP cultivars may be found in EDIS publication SC069, Maturity Curves and Harvest Schedule Recommendations for CP Sugarcane Varieties (

Cultivar Description

CP 78-1628 is grown on 7.3% of the EAA sugarcane acreage (Rice et al. 2013) and ranked sixth overall in sugarcane cultivars in Florida. This clone continues to be the most widely grown “CP” cultivar on mineral (sandy) soils in south Florida, occupying 18.1% of the total acreage on mineral soils. However, acreage under this cultivar is declining in the last few years because of grower strategies to diversify into newer rust resistant cultivars.

Maturity Curves

Figure 1 presents the sugar per ton (SPT, lb sugar per ton sugarcane biomass) for CP 78-1628 from mid-October to mid-March. Separate curves are presented for plant cane, first ratoon, second 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). The mean SPT of CP 78-1628 increased from 267 lb/ton in plant cane to 270 lb/ton in first ratoon and 274 lb/ton in second ratoon. The overall mean across crop ages ranked second out of 13 CP cultivars.

Grower recommendations are based on the entire data set across all crop ages. Early-season predicted SPT for CP 78-1628 at the onset of harvest on Oct. 14 was 207 lb/ton (ranked fifth out of 13 cultivars), and maximum predicted SPT was 288 lb/ton on Jan. 28 (ranked third out of 13 cultivars). In comparison to other CP cultivars, CP 78-1628 should be harvested during the middle 50 days of the harvest season (see CP 78-1628 has been known to dry back severely after flowering. This increases the importance of harvesting this cultivar during mid-season.

Figure 1. 

Sucrose accumulation maturity curves for CP 78-1628

[Click thumbnail to enlarge.]


Bond, R. S. 1982. Maturity differences between varieties in the selection programme. Proc. Ann. Cong. S. African Sugar Technol. Assoc. 56: 136–139.

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. Gainesville: University of Florida Institute of Food and Agricultural Sciences.

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This document is SS-AGR-214, one of a series of the Agronomy Department, UF/IFAS Extension. Original publication date April 2004. Revised October 2014. This publication is also a part of the Florida Sugarcane Handbook, an electronic publication of the Agronomy Department. For more information, contact the editor of the Sugarcane Handbook, Hardev Sandhu ( Visit the EDIS website at


M. P. Singh, assistant scientist, UF/IFAS Everglades Research and Education Center, Belle Glade, FL; H. S. Sandhu, assistant professor, UF/IFAS Everglades REC, Belle Glade, FL; R. A. Gilbert, professor and chair, Agronomy Department; J. M. Shine, Jr., Sugar Cane Grower's Cooperative of Florida, 1500 W. Sugar House Rd., Belle Glade, FL 33430; and R. W. Rice, UF/IFAS Extension Palm Beach County, Belle Glade, FL; UF/IFAS Extension, Gainesville, FL 32611.

The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.