Submitted to: Crop Science
Publication Type: Germplasm Release
Publication Acceptance Date: 4/28/2005
Publication Date: 11/1/2005
Citation: Glaz, B.S., Edme, S.J., Gilbert, R.A., Comstock, J.C., Tai, P.Y., Miller, J.D., Dunckelman, J.W., Davidson, J.O. Registration of 'cp 97-1989' sugarcane. Crop Science. 45:2660-2661. 2005. Interpretive Summary: Sugarcane is grown on organic and sand soils in the Lake Okeechobee area of south Florida. This region contributes about 25% of U.S. domestic sugar production. New cultivars that yield well on both soil types are needed, but only rarely are such cultivars identified. Experimental data of CP 97-1989 suggest that it may have acceptably high yields on sand soils. On sand soils, the cane yield of CP 97-1989 was 26.1% higher than that of the commercial reference cultivar, CP 70-1133, and the sugar content of CP 97-1989 was 5.8% lower than that of CP 70-1133. These yields of cane and sugar content resulted in a sugar per hectare yield and an economic index on sand soils that were, respectively, 21.0 and 21.1% higher for CP 97-1989 than for CP 70-1133. On organic soils, the cane yield of CP 97-1989 was 21.8% higher than that of CP 70-1133. However, its sugar content was 4.6% lower than that of CP 70-1133. Although its sugar per hectare yield was 16.3% higher than that of CP 70-1133, CP 97-1989 is not expected to be a profitable cultivar on organic soils in Florida due to its low sugar content on those soils. Cultivar resistance and tolerance are the major sources of sugarcane disease control. Complete resistance is difficult to identify and quantify because, as the plant is exposed to various disease pressures all year, new races of pathogens emerge counteracting the plant’s defense. CP 97-1989 has shown adequate resistance for commercial production in Florida to eye spot, rust, smut, and sugarcane mosaic virus. CP 97-1989 is susceptible to sugarcane yellow leaf virus, and is moderately susceptible to leaf scald and ratoon stunting disease. Its high yields in experimental plots were obtained regardless of these susceptibilities. The commercial release of CP 97-1989 makes available to Florida growers a cultivar that maintains high yields in the presence of diseases, and therefore should help to continue providing the U.S. an affordable and stable sugar supply. Additionally, CP 97-1989 will be tested extensively by sugarcane farmers in Central America, who grow mostly “CP” cultivars.
Technical Abstract: Sugarcane grown in a concentrated region near Lake Okeechobee in Florida produces 25% of the sugar produced in the U.S. The development of a constant supply of new sugarcane cultivars is critical for growers to respond to economic, pathological, and ecological pressures. The purpose of this research was to test yields, cold tolerance, and disease resistance of 15 new sugarcane genotypes in the final stage of the Canal Point sugarcane breeding program. These genotypes, along with the commercial reference standard, CP 70-1133, were evaluated in the plant-cane, first-ratoon, and second-ratoon crops in commercial fields at 10 commercial sugarcane sites in Florida. CP 97-1989, an outstanding genotype in these tests, was selected from progeny of the cross CP 75-1091 x ‘CL 61-620.’ CP 97-1989 was developed through cooperative research by the USDA-ARS, the University of Florida-Institute of Food and Agricultural Sciences, and the Florida Sugar Cane League, Inc., and was released in the autumn of 2004. The mean stalk weights of CP 97-1989 and CP 70-1133 were 1.4 and 1.5 kg, respectively. Yields of theoretical recoverable sugar and cane for CP 97-1989 were 109.2 g sugar per kg cane and 172.3 tons cane per ha, respectively, and 117.4 g per kg and 145.5 tons per ha, respectively, for CP 70-1133. This resulted in mean yields of 18.8 and 17.1 tons of sugar per ha for CP 97-1989 and CP 70-1133, respectively. CP 97-1989 has shown adequate resistance to all major diseases in Florida except to leaf scald, sugarcane yellow leaf virus, and ratoon stunting disease. Among 17 genotypes tested, including cultivars CP 72-2086 and CP 70-1133, CP 97-1989 ranked sixth for cold tolerance. Based on its high sugar and tonnage yields in the presence of diseases prevalent in Florida, CP 97-1989 may make a substantial commercial contribution to sugarcane production on sand soils in Florida.