Post-Freeze Deterioration of Six Sugarcane Cultivars1
- G. J. Gascho and
- J. D. Miller2
Sugarcane (a complex trispecies hybrid, Saccharum spp) deteriorates following a killing freeze resulting in decreased sugar recovery with time. When the freeze is severe, sugarcane becomes unmillable. Cultivar differences in deterioration rates following freezes have been reported but most modern sugarcane cultivars have not been tested under field conditions. The main objective of this study was to compare the deterioration rates of six sugarcane cultivars during a 9-week period following severe freezes at Belle Glade, Fla. 18 to 20 Jan. 1977. Samples of ‘CP 57-603’, ‘CP 68-1026’, CP 65-357', CP 68-1067', ‘Cl 41-223’, and ‘CP 63-588’ were randomly selected from the plots of a randomized complete block experiment each week. Brix, raw juice pH, titratable acidity, stalk weight, and juice polarization were measured. Theoretical yield of sugar per metric ton of cane, percent juice sucrose, percent purity, and sugar loss with time were obtained by standard calculations. Deterioration rates were estimated by regression of sugar parameters with time. All cultivars deteriorated rapidly and linearly over the 9-week period following three nights of freezes (the lowest temperature was −6 C). The average loss in theoretical sugar yield was 13 kg of suagr/metric ton of cane/week. The rate of deterioration for the 9-week period, as gauged by the data collected, was lowest for CP 65-357. During the first 5 weeks following the freezes, theoretical sugar yield and purity were highest for CP 63-588; however, during the final weeks of the experiment, juice quality was highest for CP 65-357. The mean loss of sugar for all cultivars was 9.2% per week.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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