Location: Fruit and Nut Research2009 Annual Report
1a. Objectives (from AD-416)
Develop improved varieties of peaches and plums for the southeastern United States, and improved clonal and seedling rootstocks for peach and other stone fruits.
1b. Approach (from AD-416)
Superior breeding lines and varieties with unique characters are hybridized, and the best seedlings selected. These selections are tested in multiple years and locations to identify those truly superior to existing varieties in terms of productivity, firmness and quality. These are then named and released for the public to grow. Parental rootstock lines with superior resistance to peach tree short life and Armillaria root rot as well as other desirable traits, are intercrossed to produce seedlings with the desired characteristics. Extensive testing is used to identify those hybrids which have the requisite combination of disease resistance and horticultural traits for successful commercial use.
3. Progress Report
Hybridizations were made for the peach breeding programs. Late spring frosts reduced fruit set of hybrid fruit. Additional peach and plum seedlings were planted into the field for various genetic studies as well as variety development. New peach, plum and plumcot selections were propagated for further testing. A new peach fungal gummosis screen was established to support the identification of molecular markers for resistance to this pathogen. Significant progress was made in chilling experiments to model dormancy of peach blooms. Work in cooperation with Clemson University found several molecular markers linked to chilling requirement in peach. Hand and bee pollinated crosses were made for the rootstock development program. Again late spring frost damaged those that were not under shelter. New peach tree short life, Armillaria root rot and horticultural trials were established at the Byron location. A new grower trial of advanced rootstock selections was established. Previously established grower trials at other locations are continuing to be evaluated. New root-knot nematode trials were established at locations in GA and FL. New rootstock selections were made and propagated for further development. Advanced rootstocks selections nearing release were scaled up in support of impending release(s). This report documents research conducted under a Trust Agreement between ARS and the South Carolina Foundation Seed Association. The development of new rootstocks and management practices for the control of soilborne diseases and nematodes of peach is an urgent need of the southeastern US peach industry. This has become even more apparent with the introduction of Guardian peach rootstock in 1993. Guardian has been widely adopted by the southeastern US peach industry and though it has provided exceptional resistance to peach tree short life (PTSL), it is highly susceptible to Armillaria root rot (ARR) which has now surpassed PTSL as the primary cause of premature peach tree death. The first group of plum hybrid and plum x peach hybrid rootstock selections bred in this program are nearing completion of their disease resistance and horticultural evaluations. Several items continue to stand out as potential candidates for release for commercial testing. Evaluations are continuing and the scaling up of materials to support expected release(s) have commenced. This report documents research conducted under Non-funded Cooperative Agreement No. 58-6606-8-0106, "Southeastern Peach Research" (CRIS 6606-21000-002-03N), between ARS (Byron, Georgia) and the University of Georgia. Collaborative activities, mostly entomology or pathology associate issues, were addressed regarding key insects and diseases of peach in the southeastern U.S. Several field studies were hosted on-site at the Byron Location; plus, access was provided to laboratory space and instrumentation involved in pesticide residue analysis.
1. Release and patenting of FlavrBurst peach: A wider range of high-quality peaches is needed for production in the mid-Atlantic peach industry, to provide consumers with better fruit quality. In cooperation with ARS-Kearneysville, WV, FlavrBurst peach was prepared for naming and release. A patent application was submitted in association with a nursery cooperator who will be marketing trees of the variety. This peach variety provides a less acid, high-quality fruit well-adapted for use in the mid-Atlantic peach industry.
2. Release and distribution of Gulfprince peach: The early season peach shipping industry has relied for several decades on marginally adapted materials with less than stellar reputations for shipping and eating quality. Gulfcrimson was recently released as a replacement for June Gold, a mainstay for decades in this industry segment. Budwood demand for Gulfcrimson was substantially higher than even that reported last year, its first year of commercial propagation. Gulfprince will provide a high-quality, productive peach for growers in the moderate-chill growing region, and improve consumer market quality.
Anderson, P.C., Mizell, III, R.F., Brodbeck, B.V., Beckman, T.G., Krewer, G. 2008. Abundance and consumption rate of glassy-winged sharpshooter (Hemiptera: Cicadellidae) on peaches and plums. Journal of Entomological Science. 43(4):394-407.