1977: Ph.D., Plant Pathology, University of Kentucky
1972: M. S., Plant Pathology, University of Arkansas
1970: B. S., Botany, Louisiana Tech University
1980 - Present: Associate Professor, Plant Pathology, LSU AgCenter Pecan Research-
1977- 1980: Assistant Professor, Plant Pathology, LSU AgCenter Pecan Research-
Areas of Responsibility and Work. The plant pathology position at the LSU AgCenter Pecan Research-Extension Station has a 75% research appointment and a 25% cooperative extension appointment. The pathologist is responsible for developing and conducting a research program on pecan diseases that will produce information beneficial to the commercial pecan industry of Louisiana and the other pecan producing states of the southeastern U. S. The overall extension goal is to maintain an educational program that provides pecan growers with current research-based recommendations and guidelines for pecan disease management.
Pecan disease research is currently focused on pecan bacterial leaf scorch disease, caused by the bacterial pathogen Xylella fastidiosa. Bacterial leaf scorch disease causes defoliation of trees and reduces pecan yields through reduced nutrient production and transport. Following infection by the bacterium, the disease tends to be chronic, resulting in yearly yield loss. Areas of work include determination of disease damage to the crop and tree development, evaluation of the rate and pattern of disease spread within pecan orchards, identification of potential insect vectors common to Louisiana orchards, determination of the relative roles of insect vectors and graft-transmission of the pathogen in disease introduction and spread, evaluation of cultivar susceptibility to the leaf scorch disease, and development of management techniques for this disease.
Pecan scab, caused by a fungal pathogen, has a major economic effect on pecan production by direct infection of developing nuts resulting in nut abortion or reduced nut weight. Successful commercial pecan production in the southeastern U. S. requires management of pecan scab disease through the use of multiple fungicide applications each year in conjunction with growing cultivars with a useful level of genetic resistance to the pathogen. The pathogen has a history of developing new races that can infect previously disease resistant cultivars and of developing resistance to fungicides. A program of fungicide testing is maintained to identify new products that will be efficacious against the scab pathogen. Information is collected on the development of new races of the pathogen that are adapted to popular pecan cultivars.
Previous research activities have produced information on the effects of scab disease when infection occurs at different stages of nut development and at different severity levels. Data produced from evaluation of disease susceptibilities has been used in the release of three pecan cultivars, Melrose, a Louisiana selection, and the USDA releases Houma and Oconee.
Work with other diseases has included epidemiological and control studies with vein spot disease and the late season shuck disorder complex of pecan.
Extension activities include dissemination of research results and general pecan disease management information to pecan growers in Louisiana and throughout the southeastern states through presentations at pecan grower association meetings, AgCenter Field days and orchard workshops. Written communication includes commodity publications and newsletter articles, and the LSU AgCenter Pecan Station website. Individual pecan grower concerns are addressed through, E-mails, phone calls, and requested visits to orchards.
Journal Publications: (2002 – Present)
Sanderlin, R. S. and Melanson. R. A. 2008. Reduction of Xylella fastidiosa transmission
through pecan scion wood by hot-water treatment. Plant Disease 92:1124-1126.
Sanderlin, R. S and Melanson, R. A., 2006. Transmission of Xylella fastidiosa through
pecan rootstock. HortScience 41(6):1455-1456.
Sanderlin, R. S. 2005. Cultivar and seedling susceptibility to pecan bacterial leaf scorch
caused by Xylella fastidiosa and graft transmission of the pathogen. Plant Disease 89:
Sanderlin, R. S. and Heyderich-Alger, K. I. 2003. Effects of pecan bacterial leaf scorch
on growth and yield components of cultivar Cape Fear. Plant Disease 87:259-262.
Sanderlin, R. S. 2002. Brown leaf spot (p53), Vein spot (p. 57), and Zonate leaf spot
(p. 58). Compendium of Nut Crop Diseases in Temperate Zones. Michailides, T. J.,
Teviotdale, B. L., and Pscheidt, J. W. (Eds.). American Phytopathological Society Press, St. Paul, MN. Pp. 89.