Location: Fruit and Tree Nut Research2012 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. Unusually warm spring weather resulted in poor fruit set on some parents. Peach seedlings for the collaborative moderate chill variety development program were planted into the field for evaluation. Advanced variety selections nearing completion of evaluations were scaled up in anticipation of impending release(s). Minimal evaluations were made in the high chill variety development program due to the limited number of volunteer hours available from the former incumbent (now retired). Hand and bee pollinated crosses were made for the rootstock development program. New peach tree short life, Armillaria root rot, and horticultural trials were established at the Byron location. Previously established grower trials at other locations are continuing to be evaluated and a new collaborator trial was established in Alabama. 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 completion of evaluations were scaled up in anticipation of impending release(s). Research conducted under a Trust Agreement between ARS and the South Carolina Crop Improvement Association completed for disease resistance and horticultural evaluations on the first group of plum hybrid and plum x peach hybrid rootstock selections bred in this program. Several items stand out as potential candidates for industry use and one was released in 2011 for commercial trial. Evaluations are continuing and the scaling up of materials to support expected release(s) is progressing. Substantial progress was achieved in working out a clonal propagation protocol for MP-29 rootstock which will facilitate it’s progression into large scale commercial production of finished trees for the SE peach industry. One nursery has developed a efficient tissue culture protocol as well. All three of the large commercial nurseries serving the SE peach industry have executed licensing agreements. First commercial sales of trees propagated on MP-29 will commence this Fall.
1. GulfSnow, a new low-chill mid-season peach. Traditional peach varieties utilized in the early season fresh market peach shipping industry of the southeastern United States are no longer suitable for profitable commercial production. Researchers at ARS, Byron, Georgia, jointly developed a new peach, ‘GulfSnow’, with the University of Georgia and the University of Florida, that provides an attractive, mid-season ripening, non-melting, white-fleshed peach for the fresh-market shipping industry. ‘Gulfsnow’ is adapted to moderate-chilling areas such as the lower coastal plain of the southeastern United States, and ripens about one week after ‘June Gold’ peach where it has no other white-fleshed competition in this production area. Trees produce a large, attractive, sweet tasting, non-melting, white-fleshed fruit intended for the fresh fruit market. It is expected to produce fruit with tree-ripened aroma and taste while retaining firmness for longer shelf life than fruit from conventional melting-flesh cultivars.
Beckman, T.G., Chaparro, J.X., Sherman, W.B. 2012. MP-29, a clonal interspecific hybrid rootstock for peach. HortScience. 47(1):128-131.