Location: Sugarcane Field StationTitle: Relationships between Sugarcane Canopy Reflectance and Yield Components across a Large Number of Genotypes
Submitted to: Sugar Journal
Publication Type: Abstract Only
Publication Acceptance Date: 5/22/2015
Publication Date: 6/22/2015
Citation: Zhao, D., Gordon, V.S., Comstock, J.C., Neil, G., Johnson, R.M. 2015. Relationships between Sugarcane Canopy Reflectance and Yield Components across a Large Number of Genotypes. Sugar Journal. 78(1):10.
Technical Abstract: Sugarcane (Saccharum spp.) growth and yield components are important traits in breeding and cultivar selection programs. Canopy reflectance of sugarcane during the growing season may be used to evaluate genotypes in growth and yield potential in the early stages of a sugarcane breeding program. The objectives of this study were to identify sugarcane genotypic variation in canopy reflectance and yields and to determine if there were any putative relationships between canopy reflectance and the yield variables. In the Stage 2 fields of the Canal Point sugarcane breeding and cultivar development program, canopy reflectance data were collected five to six times from each of 156 to 164 randomly selected genotypes during growing seasons (March – July) in 2011-2013 using a multispectral radiometer. Both simple vegetation index (VI = R800/R680) and normalized different vegetation index [NDVI = (R800 - R680)/(R800 + R680)] were calculated based on reflectance values at 680 and 800 nm. Yield components, including stalk population, mean stalk weight, cane yield, commercial recoverable sucrose, and sucrose yield, were determined in late October. Genotypic variation in canopy reflectance mainly occurred at the wavelengths centered 800 and 980 nm. Stalk population and cane yield were most highly correlated with reflectance at these two wavebands and NDVI (r = 0.50 - 0.68****). The best time to measure canopy reflectance for yield potential estimation across genotypes was from March to April (before canopy closure). Therefore, canopy reflectance measurements at early growth stage (110 - 150 days after planting) may be used as a tool to estimate yield potential for a wide selection of genotypes in sugarcane breeding programs.