Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/16/2000
Publication Date: N/A
Technical Abstract: In 1996, sugarcane plants infected with sugarcane yellow leaf virus (ScYLV) reported to cause yellow leaf syndrome (YLS), were discovered in Louisiana. Field experiments were established to assess the potential impact of the disease on the Louisiana sugarcane industry. In the first experiment, yield and juice quality of ScYLV-infected and unifected plants of commercial cultivar LCP 82-89 were compared. Sugar yields per unit area were reduced 6%, 11%, and 14% in plant-cane, first ratoon, and second-ratoon crops, respectively. Stalk number and tonnage were reduced in ScYLV-infected plants. Cane juice quality components, %Brix, %sucrose, %fiber, and %purity, did not differ between infected and unifected plants. Higher concentrations of soluble solids, sucrose, and purity were found in juice from virus-infected green leaf tissue compared to healthy leaf tissue. In a second experiment, juice from leaves and stalks of infected and uninfected plants collected from plant-cane and first-ratoon crops of cultivars LCP 82-89 and LHo 83-153 were analyzed. Cane juice quality components did not differ in either cultivar. In juice from virus-infected leaves, %sucrose was higher in LCP 82-89 and %purity and starch levels were higher in both cultivars, while differences in total polysaccharides and oligosaccharides were not detected. Dextran content was highly variable. Top green leaves are normally removed from the stalk by the mechanical harvester; however, they may not be removed if the cane is lodged. Leaves delivered to the mill containing elevated levels of starch may reduce processing efficiency.