Cultivar 140: Superior

Superior is a plum from the University of Minnesota. It was bred from Burbank x Kaga and distributed as a northern hybrid plum, not a European prune type [S3]. Sources place its introduction in 1932 or 1933. One prairie source says it was formerly known as Minn. 194 [S3] [S5]. It was listed for trial in South Dakota home fruit plantings and was widely sold by South Dakota nurseries. This shows it was broadly present in the northern nursery trade even where hardiness was not fully settled [S1] [S2].

The Minnesota bulletin describes the fruit in detail. It says the fruit is about 1 3/4 inches in both dimensions, cordate in form, with a pointed apex, red skin, medium bloom, and yellow flesh that is juicy and smooth [S3]. The same source rates the flavor very good and slightly tart near the skin. It also says bloom is in early May and ripening is in late August [S3]. A prairie orchard source describes the fruit as very large, conic, dark red with heavy bloom, and with yellow flesh that is tender, juicy, sprightly, and sweetish. It places the season later, from mid September to late September [S5]. These descriptions agree on a large, high quality red plum with yellow flesh, but they do not fully agree on season [S3] [S5].

Reports on the tree also give Superior a strong horticultural profile. The Minnesota bulletin calls it very vigorous, upright, and spreading, with good foliage, good fruit adherence, and heavy productivity, enough that thinning is often needed. It also notes slight susceptibility to leaf spot [S3]. This suggests a hardy breeding plum selected as much for tree performance and crop load as for dessert quality [S3].

Its cold climate record is mixed. South Dakota Extension listed it for trial in the milder and intermediate fruit growing parts of the state, not as a universally dependable plum [S1]. A Manitoba prairie source is more direct. It calls the tree tender at Morden and fruitful only after mild winters [S5]. The safest reading is that Superior was grown and tested in northern regions, but its winter performance was less dependable than that of the toughest prairie plums [S1] [S5].

In the broader archive, Superior belongs to the University of Minnesota plum breeding stream and has a clear historical pedigree through Burbank x Kaga [S3] [S5]. Later University of Minnesota research continued to use it as germplasm in fertility studies, where its seed germination and pollen storage behavior were measured alongside other winter hardy plums [S4]. Those studies are not evidence of parentage, but they do show that Superior remained part of the working northern Prunus collection decades after release [S4].

One notable modern research detail is that Superior's pollen stainability declined significantly after only three months in freezer storage. By the end of the experiment, it was one of the few plum cultivars in that study to fall below the general more-than-50-percent pattern [S4]. This does not change the cultivar's historical identity, but it adds an unusual reproductive note for breeders considering stored pollen use [S4].

Summary source basis

• S1: South Dakota Fruit Garden
• S2: Nursery Plants Available from South Dakota Nurseries
• S3: 9c684c14 7509 4b78 a803 0bf01a64aa28
• S4: {Replace with the Title of Your Dissertation}
• S5: TreeFruitsGrownInPrairieOrchards WRLeslie 1946 HQ

This summary currently draws chiefly from 9c684c14 7509 4b78 a803 0bf01a64aa28, with 8 additional supporting sources linked below.

Featured source descriptions

“Form cordate; apex pointed with russeted point; cavity moderately wide and deep; suture continuous, a line; stem 1 inch long, thick.”
— ^[9]

“Flesh is yellow, juicy, and has smooth texture.”
— ^[9]

“Has good foliage and good fruit adherence.”
— ^[9]

“Blooms early May and ripens late August.”
— ^[9]

Direct parent cultivars

• No direct linked parent cultivars promoted yet.

Parentage claim text

• Parentage: Burbank x Kaga.
• Minnesota Fruit Breeding Farm, 1932, formerly known as Minn. 194, Burbank x Kaga.
• Listed in Table 2 as P. salicina x (P. americana x P. Simonii).
• Species/background listed as P. salicina x (P. americana x P. simonii).

Derived or downstream cultivar links

• No derived or downstream lineage links yet.

Source-story quotations

• Except for the plums 'Monitor' and 'Superior', all cultivars had >50% stainability at the end of the experiment, which indicates that the majority of cultivars' pollen could potentially remain viable in storage for at least nine months.Minnesota #1695, p112
• Average % stainability for plums ‘La Crescent’, ‘Monitor’, and ‘Toka’ decreased significantly after seven months in storage whereas ‘Superior’ had a significant decrease in as few as three months in storage.Minnesota #1695, p101
• Superior (See color cut, front cover). This sensational new Plum was originated at the Minnesota Fruit Breeding Farm and is considered the most perfect Plum of all fine Plums introduced by the station.Hardy fruits for Northern planting, trees, shrubs, 1937, p8
• Superior (See color cut, front cover). This sensational new Plum was originated at the Minnesota Fruit Breeding Farm and is considered the most perfect Plum of all fine Plums introduced by the station.Hardy fruits for Northern planting, trees, shrubs, 1937, p8

Taxonomy context: No family-tree context surfaced yet.

Related cultivars mentioned in source context