Submitted to: American Society of Sugar Cane Technologists
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/11/2001
Publication Date: 6/1/2002
Interpretive Summary: Researchers recently discovered how to increase the number of varieties advanced to the final selection stage, Stage IV, from 11 to 14, without increasing resources allotted to the sugarcane breeding and selection program in Canal Point Florida. They were not certain however, that this change alone would increase the chances of identifying productive new varieties for the Florida sugarcane industry. Data were reviewed from 24 years of the breeding program to help answer this question. It was found that varieties that later became widely used commercially always yielded well in Stage III and Stage IV. However, performance across the two stages was not as consistent for less widely used commercial varieties. Finally, it was found that only increasing the number of varieties advanced to Stage IV to 14 would probably not improve probabilities of identifying new commercial varieties. Instead, the quality of varieties advanced to stages preceding Stage IV also needs to be improved.
Technical Abstract: The sugarcane breeding and selection program in Canal Point, Florida increased the number of genotypes advanced to its final selection stage, Stage IV, from 11 to 14. This change resulted from recently reported evidence that replications could be decreased without reducing experimental precision in Stage IV. The major purpose of this study was to determine if advancing an additional three new genotypes to Stage IV would improve the likelihood of identifying successful cultivars. A secondary objective was to determine if genotypes with high or mediocre yields in Stage III had similar yields in Stage IV. Data were reviewed from 24 cycles of Stage III, and 16 cycles of Stage IV. Genotype correlations between Stage III and Stage IV were significant but low for sugar yield (r = 0.27) and economic index (r = 0.28). No genotype that ranked worse than 15th in both sugar yield and economic index in Stage III was later used on more than 1% of Florida's annual sugarcane hectarage. Changes to improve the quality of genotypes advanced to Stage III will be necessary to take advantage of advancing more than 11 genotypes to Stage IV.