|Jackson, David - Mike|
Submitted to: Proceedings Florida State Horticultural Science
Publication Type: Abstract only
Publication Acceptance Date: 7/3/2006
Publication Date: 7/3/2006
Citation: Bohac, J., Olczyk, O., Jackson, D.M., Simonne, E.H., Nagata, R.T. 2006. Development of multiple pest-resistant sweetpotatoes for organic production and for new uses by ARS and IFAS [abstract]. Proceedings Florida State Horticultural Science. 119:12 Interpretive Summary: The highly nutritious sweetpotato is heat tolerant and can produce well in many areas of the Sunshine State. Both the orange-fleshed, moist sweet types and starchy dry-fleshed types are grown in the state. Due to high pest pressure in Florida, there is a need for insect resistant orange-fleshed varieties that have high resistance to soil insects, sweetpotato weevil, and root knot nematodes. These genotypes will be more suitable for organic and home garden production than the leading US cultivar, Beauregard, which is highly pest susceptible. There is also a need for improved, dry-fleshed, sweetpotato cultivars to replace 'Picadito' which has been grown for over 40 years in South Florida. These dry fleshed types are favored by consumer groups that prefer a bland starchy, staple type sweetpotato. Researchers from the US Vegetable laboratory, USDA, are working with researchers from the University of Florida to test these pest resistant breeding lines on-farm in Florida. They are also working on methods to more efficiently test for resistance in breeding materials to accelerate the development of new pest resistant varieties. The first sweetpotato cultivar released for Florida is a Boniato type named 'Liberty'. It can be grown with little or no insecticides because it is resistant to the major insect pests and nematodes. It also has potential for processed products, since it doesn’t oxidize like ‘Picadito’, and will not deteriorate for up to a year in the storage facility.
Technical Abstract: The highly nutritious sweetpotato Ipomoea batatas, is heat tolerant and can produce well in many areas of the Florida. Types grown include the orange-fleshed, sweet, moist varieties, and the starchy-dry fleshed, ‘Boniato’ varieties favored by Hispanic markets. Major pests that limit production of the crop include viruses, sweetpotato weevil, soil insects and root knot nematodes. Over many years, scientists at the USVL, ARS have developed diverse genotypes with high levels of resistance to soil insects, root knot nematodes, Fusarium, and moderate resistance to sweetpotato weevil. Some genotypes also have allelopathy to weeds like yellow nutsedge. A bioassay was developed to study the insect resistance to soil insects like Diabrotica. It was found to correlate with field insect resistance. Some of the biochemical compounds that confer resistance have been identified. The ARS scientists have joined with IFAS researchers to conduct Florida field trials to evaluate sweetpotato genotypes for resistance to insects and disease and for other horticultural traits. In recent field trials in Homestead, Florida some sweetpotato genotypes were found to be very highly resistant to the sweetpotato weevil under severe weevil pressure. The first sweetpotato cultivar released for Florida is an insect and nematode resistant cultivar named ‘Liberty’. It has excellent quality as a dry-fleshed Boniato type for fresh market. This cultivar and other USVL genotypes are superior to current Boniato varieties because the USVL genotypes do not oxidize when sliced and can be stored for up to a year. These traits are also critical for processing and value-added products.