Linda Benedict, Villordon, Arthur O., Smith, Tara, Clark, Christopher A., Labonte, Don R. | 6/5/2009 8:00:42 PM
Tara P. Smith, Don LaBonte, Christopher A. Clark and Arthur Villordon
The LSU AgCenter Sweet Potato Research Station is the only research station in the United States devoted solely to sweet potato research and development. The 308-acre station in Chase, La., was established in 1949 through a direct appropriation of the Louisiana Legislature and celebrates its 60th birthday this year.
The idea for the station started with the late Julian C. Miller, a former LSU department head and the nation’s first sweet potato breeder. In the 1930s he was able to garner enough federal grant money to conduct sweet potato research and was the first to discover how to cross the sweet potato. An office building on the LSU campus is named for Miller.
In 1949, the first foundation seed was planted at the newly established station, which was located in northeast Louisiana outside of the south central part of the state, where most of the sweet potatoes were grown at that time. By being outside the growing area, the station was also more likely to be free from the primary pest of the sweet potato – the sweetpotato weevil.
The station’s mission was to produce top-quality planting stock to serve the commercial sweet potato industry in Louisiana and also to conduct research in various disciplines to enhance production of the sweet potato, including breeding, cultural practices and pest management. Since its establishment the station has remained the hub through which sweet potato research is conducted.
The LSU AgCenter sweet potato foundation seed program has long served the Louisiana sweet potato industry by providing high quality seed to commercial producers. The station serves all parishes involved in sweet potato production in Louisiana. Foundation seed and information derived from the various research programs are available for all commercial producers and home gardeners in the state. The main sweet potato-producing parishes are West Carroll, Morehouse, Franklin, Richland, Avoyelles, Rapides, St. Landry, Evangeline and Acadia.
In addition to satisfying in-state needs, the station also supplies seed to out-of-state producers, if a supply is available. In 2007, the station began working with domestic and international entities to supply transplants for propagating purposes. This is a testament to our national and international reputation as a premier supplier of sweet potato planting stock.
The main goal of the foundation seed program is to maintain the integrity and quality of commercial varieties. The program has long worked to minimize mutations. Furthermore, because sweet potatoes are vegetatively propagated, viruses and other pathogens can accumulate and lead to variety decline, ultimately affecting yield and appearance. The cumulative effect of infection of sweet potatoes with various naturally-occurring viruses can cause yield reductions in Beauregard sweetpotato in excess of 30-40 percent, as well as cause changes in skin color and shape that reduce quality and marketability of the crop. In addition, the yield of U.S. No. 1, the highest grade, may be affected to a greater extent than total yield of the crop. As a result, the foundation seed program was converted to a virus-tested foundation seed program in 1999 to provide farmers with healthier planting stock.
Each year 10,000-15,000 bushels of foundation seed of popular commercial cultivars, including Beauregard, Evangeline, Porto Rico, Hernandez, Jewel, O’Henry and Heart-O-Gold are produced at the Sweet Potato Research Station. Quality as it relates to foundation seed is defined as seed that has been virus-tested, is free from obvious mutations or other defects, has a uniform skin, flesh color and shape and is devoid of major insect damage.
The virus-tested portion of the research is conducted at the LSU AgCenter Plant Pathology Sweet Potato Laboratory. Virus-tested tissue culture plants (Figure 1) are produced by a process termed meristem-tip culture. In this process, a tiny section (0.5 millimeter) is removed from the growing tip of a selected plant. The meristem tip is then regenerated in tissue culture into a new plant, which is then tested to ensure that all viruses have been eliminated.
Virus-tested tissue culture plants are obtained each year from the Sweetpotato Plant Pathology Laboratory and through Certis USA, a private company that increases the tissue cultures through nodal propagation techniques. Beauregard and Evangeline, the dominant commercial varieties grown in Louisiana constitute the majority of the tissue cultures received by the station, but other varieties are also increased and integrated into the program as necessary to supply the industry with planting stock of new varieties, such as the Evangeline variety initially released by the AgCenter in 2007.
The tissue culture plants are increased and transplanted into one of five greenhouse facilities at the Sweet Potato Research Station (Figure 2). All greenhouse facilities are climate-controlled and designed to exclude insects that can transmit viruses, namely aphids and whiteflies. In late spring each year, cuttings from the greenhouses are planted into production fields at the station. The foundation seed crop is grown under strict guidelines set forth by the Louisiana Department of Agriculture and Forestry. The foundation seed is sold to Louisiana sweet potato producers, who then incorporate the seed into their on-farm seed programs. The funds generated from seed sales each year constitute a portion of the operating budget for the station.
In addition to the foundation seed produced each year, sweet potato research is conducted on 15-20 acres on the station. One of the more unique projects at the station is the planting in greenhouses of approximately 15,000 true seed from the breeding nursery in Baton Rouge. Each of these seedlings is a potential new variety. Additional research topics include cultural practices, viruses and insects, diseases and weed management.
The LSU AgCenter Sweet Potato Research Station’s foundation seed and research programs ensure that Louisiana remains a leader in sweet potato production in the United States.
Tara P. Smith, Assistant Professor and Research Coordinator, Sweet Potato Research Station; Don LaBonte, Professor, School of Plant, Environmental & Soil Science, LSU AgCenter, Baton Rouge, La.; Christopher A. Clark, Professor, Department of Plant Pathology & Crop Physiology, LSU AgCenter, Baton Rouge, La.; and Arthur Villordon, Associate Professor, Sweet Potato Research Station, Chase, La.
(This article was published in the spring 2009 issue of Louisiana Agriculture.)