Location: Sugarcane Research2010 Annual Report
1. Leaf Reflectance Provides an Estimate of Sugarcane Sucrose Levels. Current methods used to estimate sugarcane stalk sucrose levels prior to harvest are labor and time intensive. Reflectance data ware collected from the leaves of predominant sugarcane varieties that were sampled throughout the harvest season (during the 2005 and 2006 crop years) to determine sucrose accumulation (maturity). Leaf reflectance was effective at predicting sucrose in 36 to 79% of the cases if varieties were combined, and in 65 to 100% of the cases if the varieties were considered separately. Regression analyses also identified several spectral regions that appeared to be important in describing stalk sucrose levels, including: ultraviolet, blue, green and yellow, orange and red, and the near-infrared wavelengths. These combined results indicate that it may be possible to utilize remote sensing techniques to estimate sugarcane maturity prior to harvest which would allow growers and mills to more effectively manage field and varietal harvest schedules to insure maximum sucrose yields.
2. Early Harvest Affects Ratooning Ability in Louisiana. The number of sugarcane processors in Louisiana has decreased over time forcing growers to begin the harvest season earlier for fear of complete cane loss at the end of the harvest period due to freezing temperatures. Experiments were conducted to investigate effects of early harvest on ratooning ability and to determine differential effects of early harvest among Louisiana varieties. Averaged across all varieties, the October harvest of plant-cane reduced sugar yields of the first-ratoon (7,700 kg/ha) compared to the mid-season harvest date (10,100 kg/ha.) Averaged across all varieties, the October harvest of both plant-cane and first-ratoon reduced sugar yields of the subsequent second-ratoon (5,500 kg/ha) compared to the December harvest (10,000 kg/ha). Both harvest dates for L 97-128 had equivalent yields, so this variety is best suited for early harvest if only harvested early once in a four-year cycle. All cultivars had decreased yields with consecutive years of early harvests. When developing harvest schedules, growers should consider the potential 24 to 45% yield loss in subsequent ratoons associated with the early harvest of plant-cane and first-ratoon crops.Viator, R.P., Dalley, C.D., Johnson, R.M., Richard Jr, E.P. 2010. Early harvest affects ratooning ability in Louisiana. Sugar Cane International. 28(3):123-127.