Identifying Physiological and Yield‐Related Traits in Sugarcane and Energy Cane

CORE IDEAS: Energy cane may be an alternative crop on sand soils in the future to improve profits. It is unclear if energy cane differs from sugarcane in physiology and yield on sand soils. Energy cane had 26 to 35% greater normalized difference vegetation index and 21% higher yield than sugarcane. Increased yield of energy cane was associated with great normalized difference vegetation index and high stalk population rather than leaf net photosynthetic rate. A growing interest of producing sugarcane (a complex hybrid of Saccharum spp.) for both sugar and bioenergy and saturation of using organic soils provide an opportunity to expand production on mineral (sand) soils. However, sugarcane yields and profits on sand soils are generally low. Energy cane may be an alternative on sand soils in the future to improve profits. The objective of this study was to identify physiological and biomass traits of sugarcane and energy cane growing on sand soils. Two commercial sugarcane cultivars and two energy cane clones were planted at two sites with sand soils in southern Florida. Data were collected on plant‐cane, first‐ratoon, and second‐ratoon crops. Leaf relative chlorophyll level (SPAD), photosynthetic rate (Pn), and canopy reflectance were measured during tillering and grand growth. Normalized difference vegetation index (NDVI) was calculated based on canopy reflectance data. Stalk population, diameter and length, and aboveground biomass yields were determined when plants reached maturation. Although there were no consistent differences between sugarcane and energy cane in leaf SPAD, Pn or NDVI of plant cane, energy cane had 26 to 35% greater NDVI values than sugarcane in the ratoon crops. Energy cane showed 21% higher dry biomass than sugarcane, averaged across sites and crops. Increased biomass production of energy cane was mainly associated with high stalk population, long stalk, and great NDVI rather than leaf Pn or stalk diameter. The findings of this study on physiological parameters of energy cane vs. sugarcane can be useful for improvement of knowledge and future research.