Search Results
Abstract
Six sweet potato (Ipomoea batatas (L.) Lam.) lines with a wide range of objectionable fiber content were grown in one location in 1976 and in 2 locations in 1977 to study factors influencing the expression of that trait. We failed to identify environmental factors that would enhance expression of objectionable fiber but did find that large roots tended to have more objectionable fiber than did smaller roots. All roots of high fiber lines did not express objectionable amounts. About 10 US #1 but only 4 jumbo roots of each line would have to be evaluated to have a 95% probability of observing objectionable fiber in high fiber lines. However, Jumbo, US #1 and canning sizes all led to the same relative rankings of lines. Subjective evaluations of baked roots were as effective as objective laboratory tests and could be obtained concurrent with other necessary baking evaluations.
Abstract
‘Sumor’, a multi-use sweet potato [Ipomoea batatas (L.) Lam.], was developed jointly by the Agricultural Research Service, U.S. Department of Agriculture, U.S. Vegetable Laboratory, and Clemson Univ., South Carolina Agricultural Experiment Station, Edisto Research and Education Center. This cultivar has potential as a high dry matter type for ethanol production and as a white-fleshed garden potato.
Abstract
‘HiDry’ is a high dry matter (DM) yielding sweet potato cultivar with high DM content developed jointly by Clemson Univ. and the USDA for industrial uses. It possesses high levels of multiple disease and insect resistances.
Abstract
Correlation studies indicate visual and Hunter Lab Color and Color Difference Meter aL ratings are of comparable value for classifying flesh color of sweet potato [Ipomoea batatas (L.) Lam] roots. Dry matter content was correlated with flesh color, specific gravity, and dry matter yield and with sugar, starch, and sugar + starch (fermentables) contents. Dry matter yield, starch yield, and other responses of seedlings with light and with dark orange flesh color were as expected from correlation studies. Light flesh color and high specific gravity, in combination with high field yield, appear to be useful selection traits for expediting development of cultivars for industrial uses.
This study was designed to determine if the preference of soil insects for sweetpotato [Ipomoea batatas (L.) Lam.] cultivars is affected by the proximity of resistant or susceptible plant cultivars at various spacings. Comparisons were made for damage caused by wireworms (Conoderus spp.), Diabrotica spp., Systena spp., sweetpotato flea beetles (Chaetocnema confinis Crotch), and grubs (Plectris aliena Chapin; Phyllophaga ephilida Say) in previously reported resistant and susceptible cultivars. Field plots were planted with a resistant cultivar, a susceptible cultivar, or the two cultivars intermixed. Large roots exhibited more insect damage than medium and small roots. When plant spacing was increased, roots were larger and insect damage more severe. Mixed plantings of resistant and susceptible cultivars significantly reduced insect damage in the susceptible plants. Planting regime did not influence insect damage for the resistant cultivars.
This 2-year study was conducted to determine if soil insect damage could be reduced in sweetpotato [Ipomoea batatas (L.) Lam] by treatment with an insecticide (fonofos) and/or a parasitic nematode (Steinernema carpocapsae Weiser), in conjunction with sweetpotato cultivars that differed in susceptibility to soil insect damage. Analysis of field data for the first year showed that the parasitic nematode provided significant damage protection of sweetpotato from wireworms (Conoderus spp.), Diabrotica sp., Systena sp., and sweetpotato flea beetle (Chaetocnema confinis Crotch), but not from grubs (Plectris aliena Chapin; Phyllophaga ephilida Say). In this same test, fonofos used alone provided protection against wireworm-Diabrotica-Systena (WDS complex) damage. In the second test, the nematode did not provide soil insect protection for the WDS complex, but fonofos did reduce damage for these insects. Poor efficacy in the second test with the nematode probably was due to high rainfall, which saturated the soil. Resistant cultivars provided good protection for all three categories of damage. When used with the insect-susceptible check `SC 1149-19', the nematode or fonofos treatments provided better control for all insect categories in the first test. In both years, much higher control of damage by all insect classes was achieved by the use of resistant cultivars in combination with the nematode and/or fonofos treatment (64% higher crop protection than the susceptible check line). Chemical name used: O-ethyl-S-phenylethylphosphonodithioate [fonofos (Dyfonate 10G)].
Abstract
Six sweet potato (Ipomoea batatas (L.) Lam.) breeding lines, W-71, W-115, W-119, W-125, W-149 and W-154, possessing moderate levels of resistance to the sweet potato weevil, Cylas formicarius elegantulus (Summers), in combination with resistances to other released. They have dark orange flesh, relatively high yields and generally acceptable canning and baking qualities.
Abstract
‘Southern Delite’ sweet potato [Ipomoea batatas (L.) Lam.] was developed jointly by the USDA and the South Carolina Agricultural Experiment Station. This cultivar has high yield and excellent baking qualities, in combination with high levels of resistance to a wide array of disease and insect pests.