Jeffrey W. Hoy
The bacteria and viruses that cause diseases of sugarcane in Louisiana are distributed throughout an infected plant. An important control measure for these systemic diseases is a healthy seedcane program. Sugarcane is vegetatively propagated by planting stalk sections, and new plants develop from buds on the planted stalks. Planting infected stalks will result in the spread and increase of systemic diseases. To prevent this, Louisiana sugarcane farmers must have access to sources of healthy seedcane.
The first attempts to provide healthy planting material involved heat treatment of cane stalks to eliminate the bacterial pathogen causing ratoon stunting disease (RSD). Industrywide, this approach was only moderately successful at controlling RSD, and it did not provide control of several other diseases.
A lab technique known as tissue culture was then successfully used by a private Louisiana company to mass produce healthy plants. A partnership between the public and private sectors evolved to provide certified, healthy seedcane for farmers. The seedcane certification program is operated by the Louisiana Department of Agriculture and Forestry in cooperation with the LSU AgCenter and two seedcane companies. The AgCenter Sugarcane Disease Detection Laboratory, which receives support funding from the seedcane companies and the American Sugar Cane League, has multiple roles in the process.
The AgCenter lab starts the process by providing healthy plant material of new varieties to the two commercial seedcane companies that they then use as the source of tissue for culturing healthy seedcane. The lab then monitors several diseases during the seedcane increase process. In addition, monitoring for RSD and another systemic virus disease, yellow leaf, is provided for the AgCenter sugarcane variety development program, the American Sugar Cane League variety release program, and commercial sugarcane farmers. Both diseases do not cause reliable external symptoms, so disease testing is needed to ensure that disease control has been successful.
The first healthy seedcane program developed for sugarcane attempted to control one disease, RSD, with heat treatment. Now, a certified healthy seedcane program using tissue culture can provide control of five systemic diseases: RSD, yellow leaf, leaf scald, smut and mosaic. This represents a major advance in disease control for the Louisiana sugarcane industry.
Jeffrey W. Hoy, Professor, Department of Plant Pathology & Crop Physiology, LSU AgCenter, Baton Rouge, La.
(This article was published in the spring 2008 issue of Louisiana Agriculture.)