Submitted to: Arthropod Management Tests
Publication Type: Research Notes
Publication Acceptance Date: November 26, 2003
Publication Date: November 26, 2003
Citation: JACKSON, D.M., BOHAC, J. 2003. EVALUATION OF DRY-FLESHED SWEETPOTATO GERMPLASM FOR RESISTANCE TO SOIL INSECT PESTS IN SOUTH CAROLINA, 2001. ARTHROPOD MANAGEMENT TESTS, Volume 28, Report No. M15, Online journal at http://www.entsoc.org/pubs/index.html. Interpretive Summary: Most commercial dry-fleshed sweetpotato cultivars have little resistance to soil insect pests, which can severely limit marketable yields. Thus, there is a need to develop new varieties that have increased levels of insect resistance. This report describes the field evaluation of advanced dry-fleshed sweetpotato entries from the USDA ARS/Clemson sweetpotato breeding program at the U. S. Vegetable Laboratory (USVL), Charleston, SC. Thirty nine sweetpotato germplasm entries, including three insect susceptible check cultivars, were evaluated for insect resistance in replicated field trials at Charleston, SC. Several of the advanced, dry fleshed germplasm lines were more resistant to soil insect pests than were the susceptible check varieties. The most promising of these advanced clones will be developed as breeding lines or new sweetpotato varieties.
Technical Abstract: This report describes two field evaluations of advanced dry fleshed sweetpotato germplasm from the USDA ARS sweetpotato breeding program at the U. S. Vegetable Laboratory (USVL), Charleston, SC. The first field experiment included two insect susceptible, moist orange fleshed check cultivars ('Beauregard' and 'SC1149 19'), two insect susceptible, dry fleshed checks ('Picadito' and 'GA 90 16'), two insect resistant, dry fleshed checks ('White Regal' and 'Sumor'), and 23 mostly dry fleshed advanced entries that were evaluated for insect resistance in replicated field trials at the USVL. The second experiment consisted of an insect susceptible, dry fleshed check ('Picadito'), two insect resistant, dry fleshed checks ('White Regal' and 'Sumor'), and 11 mostly dry fleshed entries. For the first experiment, there were highly significant entry effects for percent uninjured roots, WDS index (Wireworm, Diabrotica, Systena), percent sweetpotato weevil damaged (Cylas formicarius elegantulus) roots, and percent flea beetle damaged (Chaetocnema confinis Crotch) roots, but not for percent grub damaged (Plectris aliena Chapin and/or Phyllophaga spp.) roots. Twenty advanced breeding lines had a significantly higher percentage of undamaged roots than 'SC1149 19', and five advanced breeding lines had a significantly higher percentage of undamaged roots than either 'Beauregard' or 'Picadito'. Five of the entries had significantly lower WDS rating than any of the susceptible check cultivars ('Beauregard', 'GA 90 16', 'Picadito', 'SC1149 19'). Nineteen entries had a significantly lower percentage infestation by SPFB than did 'SC1149 19'. All entries had a significantly lower percentage of infestation by SPW than did 'SC1149 19'. For the second experiment, there were significant differences only for entry effects for WDS and percent uninjured roots, but not for percent flea beetle infestations, percent grub infestations, or percent SPW infestations.