|Jackson, David - Mike|
Submitted to: Arthropod Management Tests
Publication Type: Research notes
Publication Acceptance Date: 11/26/2003
Publication Date: 11/26/2003
Citation: JACKSON, D.M., BOHAC, J., MUELLER, J.D. 2003. EVALUATION OF PLANT INTRODUCTIONS AND DRY-FLESHED SWEETPOTATO GERMPLASM FOR RESISTANCE TO SOIL INSECT PESTS, 1998. ARTHROPOD MANAGEMENT TESTS, Volume 28, Report No. M12, 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 seven sweetpotato germplasm entries, including four insect susceptible check cultivars, were evaluated for insect resistance in replicated field trials at Charleston and Blackville, 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 the field evaluation of dry fleshed plant introductions (PI) and advanced dry fleshed sweetpotato germplasm from the USDA ARS/Clemson sweetpotato breeding program at the U. S. Vegetable Laboratory (USVL), Charleston, SC. The first experiment included an insect susceptible, moist orange fleshed check cultivar ('SC1149 19'), an insect resistant, moist orange fleshed check ('Regal'), an insect susceptible, dry fleshed check ('Picadito'), two insect resistant, dry fleshed checks ('White Regal' and 'Sumor'), 6 PIs, and 23 mostly dry fleshed advanced germplasm entries that were evaluated for insect resistance in replicated field trials at the USVL. There were highly significant entry effects for percent uninjured roots, WDS index (Wireworm, Diabrotica, Systena), and percent grub damaged (Plectris aliena Chapin and/or Phyllophaga spp.) roots, but not for percent flea beetle damaged (Chaetocnema confinis Crotch) roots. Thirty resistant checks and advanced breeding lines had a significantly higher percentage of undamaged roots than 'SC1149 19', and eight entries had a significantly higher percentage of undamaged roots than 'Picadito'. All entries had a significantly lower WDS rating and a significantly lower percentage infestation by grubs than did 'SC1149 19'. The second experiment, which had the same check cultivars, 6 PIs, and 12 mostly dry fleshed advanced entries, was planted at the Clemson University, Edisto Research and Education Center, Blackville, S.C. There were highly significant entry effects for percent uninjured roots and WDS index, but not for percent grub damaged or percent flea beetle damaged roots. All entries, except 'Picadito' and PI 538354, had a significantly higher percentage of undamaged roots and a significantly lower WDS rating than 'SC1149 19', and 19 entries were better than 'Picadito'.