Genetic Contribution to Yield Gains in the Florida Sugarcane Industry across 33 Years

Abstract

Sugarcane (Saccharum spp.) is a successful crop in the Florida Everglades Agricultural Area (EAA) that is characterized by high‐N organic and low‐fertility sandy soils, periodic freeze, and flood events. After 50 yr of breeding, the possibility of a yield plateau was investigated in the cooperative Florida sugarcane breeding program via an assessment of yield gains in the industry and an evaluation of the contribution attributed to breeding efforts. Long‐term commercial and selection trial data, covering a 33‐yr period (1968–2000), were used in single‐degree‐of‐freedom regression analyses to determine rates of improvement in sucrose content (SC; kg Mg−1), cane yield (CY; Mg ha−1), and sugar yield (SY; Mg ha−1). Analyses of commercial data reflected yearly increases of 0.80 ± 0.08 kg Mg−1 of cane for SC, 0.31 ± 0.10 Mg ha−1 for CY, and 0.10 ± 0.01 Mg ha−1 for SY. Corresponding gains from selection trial data were 0.74 ± 0.15 kg Mg−1, 1.06 ± 0.40 Mg ha−1, and 0.16 ± 0.05 Mg ha−1, respectively. Improvements were significant for all three traits across plant‐cane, and first‐ and second‐ratoon crops grown on organic soils but not on sandy soils. About 69% of the total gain in SY was attributed to the cooperative Canal Point public breeding program, via a greater allocation of assimilates toward sucrose accumulation, resulting in a contribution of $99 to 203 million as additional profits to the Florida economy across the 33 yr. The genetic potential of the working germplasm has not been exhausted (no evidence of a yield plateau for SC) in this sugarcane breeding program. These gains and future advances are possible because of the use of a diverse gene pool and a breeding strategy that integrates growers’ participation into the program.

U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

“…This is dependent on temperature and sunlight, and would probably occur under tropical conditions. Sugarcane breeding programs have reported sugar yield gains in the order of 1% to 2% per year (Edme et al, 2005). The economic sustainability of growing energy cane in nontraditional cane growing regions will require yearly biomass yield gains of this magnitude or greater, with a goal of ensuring that the I/O ratio of 1:8 projected for tropical countries can be met and ultimately exceeded under the sub-tropical cane growing conditions of the southeastern United States.…”

Sugarcane Response to Water-Deficit Stress during Early Growth on Organic and Sand Soils

“…A major goal of the Canal Point (CP) sugarcane cultivar selection program in Florida is to develop high-yielding cultivars with disease resistance and tolerance to abiotic stresses for organic (muck) and sand soils (Glaz and Kang, 2008). Edme et al (2005) reported that, for a 33-year period, about 69% of the sugar yield gain in south Florida was from genetic improvements attributable to the CP cultivar selection program, but these yield gains were mainly associated with muck rather than sand soils. Based on these findings, scientists in Florida are conducting a comprehensive review of the CP program to identify breeding and management strategies that will improve sugarcane yields for sand soils without compromising the progress being made for muck soils (Glaz and Kang, 2008).…”

“…Stress symptoms of sugarcane on sand soils in Florida are generally not so extreme that they are detected visibly. However, based on the low yields and lack of genetic gain on sand soils (Edme et al, 2005), we hypothesized that physiological processes are negatively affected by abiotic stresses, especially water-deficit stress during sugarcane formative growth on the Florida sand soils. Therefore, identification of physiological and growth responses in sugarcane to water-deficit stress should aid to better understand physiological mechanisms and improve cultivar selection and field management for sand soils in Florida.…”

Screening for Sugarcane Brown Rust in the First Clonal Stage of the Canal Point Sugarcane Breeding Program

“…Cane yield (TCH, Mg ha −1 ), commercial recoverable sucrose (CRS, kg sucrose Mg −1 cane), and sucrose yield (TSH, Mg ha −1 ) with disease resistance are the major agronomic traits considered in advancing sugarcane clones during the selection stages. Edmé et al [11] reported that CRS, TCH, and TSH of the Florida commercial sugarcane cultivars linearly increased by 26.0, 15.5, and 47.0%, respectively, over a 33-year period from 1968 to 2000. Underscoring the critical need for cultivar development for the Florida sugarcane industry, about 69% of the sugar yield gain in Florida was from genetic improvement attributable to the CP program [11], indicating importance of the CP program in sustaining sugarcane production in Florida.…”

“…Edmé et al [11] reported that CRS, TCH, and TSH of the Florida commercial sugarcane cultivars linearly increased by 26.0, 15.5, and 47.0%, respectively, over a 33-year period from 1968 to 2000. Underscoring the critical need for cultivar development for the Florida sugarcane industry, about 69% of the sugar yield gain in Florida was from genetic improvement attributable to the CP program [11], indicating importance of the CP program in sustaining sugarcane production in Florida. Brown rust (Figure 1), caused by Puccinia melanocephala Syd.…”