|Hoy, Jeff - LSU AG CENTER, B.R., LA|
|Godshall, Mary - SPRI, INC., NO., LA|
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: April 22, 2005
Publication Date: July 20, 2005
Citation: Grisham, M.P., Hoy, J.W., Godshall, M.A., Eggleston, G. 2005. Effect of Sugarcane Yellow Leaf Virus on Sugarcane Yield and Juice Quality of LCP 85-384 and Ho 95-988 [abstract]. Journal of the American Society of Sugar Cane Technologists. 25:110-111. Available: http://www.assct.org/journal/journal.htm Technical Abstract: Sugarcane yellow leaf virus (SCYLV) was first detected in Louisiana in 1996 and has since been repeatedly detected in the leading commercial cultivar, LCP 85-384. A field experiment was conducted from 2001 to 2003 to determine the effect of SCYLV infection on yield and juice quality of LCP 85-384. The experiment was repeated from 2003 to 2004 and expanded to include cultivar Ho 95-988 as well as LCP 85-384. The experiments were harvested green with a chopper harvester and billet samples were collected for juice and cane analysis by the pre-breaker, core press method. Prior to harvest, whole-stalk samples with green leaves attached were hand cut from each experimental plot. The whole stalks were divided into four sections (the lower six internodes of the stalk, the upper mature internodes of the stalk, the immature portion of the upper stalk that included the growing point, and the green leaves) for detailed juice analysis. Neither sugar nor cane yields differed between the SCYLV-infected and non-infected plots in plant-cane or first-ratoon crops of either cultivar. In the second-ratoon crop of LCP 85-384, sugar and cane were reduced by approximately 10% in the SCYLV-infected plots. Increased starch accumulation was found in the growing point and the green leaf sections of the SCYLV-infected stalks of both varieties as compared to the non-infected tissues. The mean starch concentrations in LCP 85-384 increased from 940 to 1160 ppm (23%) and from 2700 to 4050 ppm (50%) in the growing point section and the green leaves, respectively. In Ho 95-988, the mean starch concentration increased from 1100 to 1540 ppm (40%) and from 940 to 1490 ppm (57%) in the growing point section and the green leaves, respectively. The majority of green leaves and immature sections of stalks is normally removed when cane is harvested with chopper harvesters; however, these tissues may not be removed if the harvester is not being operated at full extractor fan efficiency, when the cane is lodged, or when harvesting under rainy conditions. Although SCYLV-infected sugarcane plants in Louisiana rarely show the typical external symptoms of midrib yellowing and dying tops associated with SCYLV infection, elevated levels of starch in the cane delivered to the mill could reduce processing efficiency.