|DEL BLANCO, ISABEL - Former ARS Employee|
|MILLIGAN, SCOTT - Monsanto Corporation|
|GLYNN, NEIL - Syngenta Seeds, Inc|
|DAVIDSON, R WAYNE - Florida Sugarcane League|
|IREY, MIKE - Us Sugar Corporation|
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 5/4/2013
Publication Date: 6/13/2013
Citation: Mccord, P.H., Del Blanco, I., Milligan, S., Glaz, B.S., Glynn, N.C., Davidson, R., Irey, M. 2013. Sugarcane Genotype Selection on Muck and Sand Soils in Florida — a Case for Dedicated Environments. American Society of Sugar Cane Technologists. pp3.
Technical Abstract: Traditionally, the cooperative sugarcane (Saccharum spp.) breeding program located at Canal Point has selected genotypes exclusively on muck soils in the early to middle stages of the program. Only about 0.20% of genotypes are ever tested on sand, resulting in the possibility that many sand-adapted genotypes are discarded. The objective of this study was to determine the presence of genotype by soil interaction on muck and sand soils, amongst sugarcane genotypes in the second clonal selection stage. A significant genotype by soil interaction for important yield traits would warrant the selection of genotypes on sand soils at earlier stages. The trials were planted on a Torry muck soil at the USDA-ARS Sugarcane Field Station in Canal Point, Florida in 2006 and 2007 and on a Margate sand soil at U.S. Sugar Corporation’s Townsite farm near Clewiston, Florida in 2007 and 2008. Limited seedcane availability necessitated planting the same series (2006 and 2007) in different years at different sites, resulting in a confounding of location with year for each series. The new genotypes were planted in unreplicated plots, except for a small subset which had two replications. Each trial included replicated plots of the check cultivars CP72-2086, CP78-1628, and CP89-2143. Check cultivars and new clones were analyzed for average stalk weight, number of stalks per acre, tons of cane per acre, theoretical recoverable sucrose, tons of sucrose per acre, commercially recoverable sucrose, Brix, and percent sucrose. Genotype by soil interaction was modeled using the check cultivars. Within either location, a significant genotype by year effect was present for only two of the eight traits measured. In 2007, the year when checks were grown in both locations, a significant genotype by location effect was detected for five of the eight traits. These results suggest that significant genotype by soil interactions amongst the new genotypes are due more to differences between the soils than the years. Significant interactions were detected amongst the replicated new clones for five of eight traits in the 2006 series, but only three traits in the 2007 series, likely due to the reduced power of a smaller number of clones. For all new clones, the Spearman (rank) correlation was calculated for each trait across locations. All correlations were statistically significant, but the values were low, ranging from 0.17 to 0.38. The exception was stalk weight, which was moderately correlated (0.50) between locations in both sets. These data indicate that clones that are highly ranked for a trait in one location may not be highly ranked in another. Taken together, our results strongly suggest that the Canal Point breeding program should begin genotype selection on sand at earlier stages in order to increase the likelihood of identifying superior cultivars for these soils.