Author
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Edme, Serge |
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Miller, Jimmy |
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Glaz, Barry |
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Tai, Peter |
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Comstock, Jack |
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Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/28/2004 Publication Date: 1/1/2005 Citation: Edme, S.J., Miller, J.D., Glaz, B.S., Tai, P.Y.P., Comstock, J.C. Generic contribution to yield gains in the Florida sugarcane industry across 33 years. Crop Science. 45:92-97. 2005. Interpretive Summary: The Florida sugarcane industry has long awaited a quantification of the success realized by the USDA-ARS Canal Point (CP) sugarcane breeding program. This study aims at assessing the impact of the breeding on cultivar improvement for the Florida sugarcane industry. Yield gains obtained over a 33-year period (1968-2000) were calculated by using commercial production data and long-term yield trials data from the final stage (Stage IV) of the CP breeding program. Analyses of commercial data reflected yearly increases of 0.81 kg Mg-1 for sucrose content, 0.31 Mg ha-1 for cane yield, and 0.10 Mg ha-1 for sugar yield. Corresponding gains from the final selection trials were 0.74 ± 0.15 kg Mg-1, 1.24 ± 0.40 Mg ha-1, and 0.16 ± 0.05 Mg ha-1. Improvements were significant for all three traits across plant-cane, first- and second-ratoon crops grown on organic soils, but not on sandy soils. About 70% of the gain in sugar yield was attributed to the Canal Point public program, contributing $99-203 million as additional profits to the Florida economy over the last 33 years. There was no evidence of a yield plateau, i.e. the genetic yield potential of the working germplasm has not been exhausted in this sugarcane breeding program. These gains and future advances can be attributed to the use of a diverse gene pool and a shuttle breeding strategy (that alternates selection between optimum and multi-location environments), combined with a highly farmer-participatory breeding program. Technical Abstract: Sugarcane (Saccharum spp.) breeders have been successful in adapting the crop to the south Florida environment, characterized by high-N organic and low-fertility sandy soils, periodic freeze and flood events, and several diseases. This study assesses genetic yield advances in the Florida sugar industry and evaluates the contribution attributed to breeding efforts. Long-term commercial and selection trial data, covering a 33-year period (1968-2000), were used in single-degree-of-freedom regression analyses to determine the 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 0.81 ± 0.08 kg Mg-1 for SC, 0.31 ± 0.10 Mg ha-1 for CY, and 0.10 ± 0.01 Mg ha-1 for SY. Corresponding gains from the final selection trials were 0.74 ± 0.15 kg Mg-1, 1.24 ± 0.40 Mg ha-1, and 0.16 ± 0.05 Mg ha-1. Improvements were significant for all three traits across plant-cane, first- and second-ratoon crops grown on organic soils, but not on sandy soils. About 70% of the gain in SY was attributed to the Canal Point public program, contributing $99-203 million as additional profits to the Florida economy over the last 33 years. The genetic yield potential of the working germplasm has not been exhausted (no evidence of a yield plateau) in this sugarcane breeding program. These gains and future advances are possible due to the use of a diverse gene pool and a shuttle breeding strategy, combined with a highly farmer-participatory program. Abbreviations: EAA=Everglades Agricultural Area; SC=sucrose content; CY=cane yield; SY=sugar yield; CP=Canal Point |
