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Alderman is a large, sweet, Japanese-type plum hybrid that will thrive in cold climates where other high-quality Japanese-type plums may suffer winter injury. It was named after Professor W.H. alderman in honor of his 100th birthday in 1985 and in recognition of his many accomplishments in horticulture science at the University of Minnesota.
Alderman originated from a cross of Burbank (P. salinina) x Older (P. salicina x P. americana) made by Professor Alderman. It was tested as MN 416 at experiment stations at Excelsior, Grand Raids, and Morris, Minnesota, between 1945 and 1984.
Trees if Alderman are vigorous and reach 12 to 15 feet in height when mature. The growth habit is round-headed and spreading. Trees are precocious, bearing fruit as early as one year after planting. Flowers are profuse, white, and 1 to _ inches in diameter, making the cultivar desirable as a landscape plant as well as for its fruit production. Alderman requires cross pollination by a compatible cultivar such as Toka or South Dakota for successful fruiting.
The fruit is clingstone and oval to heart-shaped. It ripens in mid-august. Average fruit size is 1 _ to 2 inches in diameter and 2 to 2 _ inches in length. The skin is burgundy-read and smooth and has little or no bloom. The flesh, which is bright golden-yellow, is sweet, juicy, and moderately soft. Fresh fruit quality is excellent, being notably sweeter than other cultivars commonly grown in the north-central United States. The fruit also can be used for preserves. Brown rot and plum curculio have been noted as pest problems but appear to be no more severe than with other cultivars and have been controlled by routine spray programs.
Alderman fruited consistently and showed little winter injury at Excelsior between 1972 and 1983. Trees also have survived well in harsher climates at Morris and Grand Rapids. Laboratory freezing tests indicate that Alderman is as hardy as hardy high-quality plums such as superior and Underwood.
Alderman is propagated by cooperating nurseries under a royalty agreement with the Minnesota Nurseryman's Research Corporation.
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