Cultivar 360: Zeta

Zeta is a University of Saskatchewan Prunus introduction from the Sapa x Oka breeding line, recorded as mixed open pollination and introduced in 1960.[S1] [S3] It is part of the prairie group of cherry-plum or plum hybrids built around these cold climate selections, and its name appears among a larger group of related Saskatchewan introductions from the same cross.[S1] [S3]

The source trail is short but clear on origin. Prairie cultivar indexes list Zeta under the University of Saskatchewan with Sapa x Oka parentage and a 1960 year reference, while the university introduction list gives the selection code C59-355 and repeats the same parentage and introduction year.[S1] [S3] This places it within early Saskatchewan breeding work that used sand cherry plum hybrid material to produce fruit for prairie conditions.[S1]

Sources describe the fruit as spherical, with bluish skin and dark red flesh, and say the flesh is very mildly acid with good overall quality.[S3] Saskatchewan fruit tables add that the fruit is about 1 to 1 1/8 inches across, juicy, and dark purple to dark red in the flesh.[S2] A second table description is less favorable, calling the skin medium thick, tough, and astringent, and rating the flavor astringent and dessert quality poor.[S2] Sources disagree on the skin description, from bluish to green with purple mottling. They also disagree on eating quality, from good to poor.[S2] [S3]

The cited material does not give clear notes on tree habit, bearing, productivity, or disease. Hardiness is also not stated directly for this plum introduction in the usable Zeta records here. Its Saskatchewan origin and inclusion in prairie cultivar indexes place it in a cold climate breeding context, but that is weaker than a direct winter survival statement.[S1] [S2]

Zeta matters mainly as one named member of the University of Saskatchewan Sapa x Oka family.[S1] [S3] Even in these short records, it shows how prairie breeders worked within a tight hybrid lineage and selected distinct named fruits from it, preserving differences in color, acidity, and fruit quality that might otherwise disappear into a generic breeding note.[S1] [S3]

Summary source basis

• S1: An index of fruit cultivars tested or developed on the Canadian prairies.
• S2: hortfacts_1976_3.pdf
• S3: University of Saskatchewan fruit introductions 1959-1960

This summary currently draws chiefly from hortfacts_1976_3.pdf, with 3 additional supporting sources linked below.

Featured source descriptions

“Skin described as medium thick, tough, astringent; flesh as dark purple and juicy.”
— ^[4]

“Tested primarily in Zones 4 and 5, where it showed moderate to severe winter injury.”
— ^[4]

“Flavor listed as astringent.”
— ^[4]

“Dessert quality listed as poor.”
— ^[4]

Direct parent cultivars

• No direct linked parent cultivars promoted yet.

Parentage claim text

• Listed as 'Sapa' x 'Oka'.
• Parentage listed as Sapa x Oka, from mixed open pollinations.

Derived or downstream cultivar links

• No derived or downstream lineage links yet.

Source-story quotations

• C59-355 Zeta ... Sapa x Oka Mixed open pollinations ... 1960 ... Spherical, skin bluish, flesh dark red and very mildly acid, quality good.University of Saskatchewan fruit introductions 1959-1960, p9
• C59-355 Zeta ... Sapa x Oka Mixed open pollinations ... 1960 ... Spherical, skin bluish, flesh dark red and very mildly acid, quality good.University of Saskatchewan fruit introductions 1959-1960, p9
• C59-355 Zeta ... Sapa x Oka Mixed open pollinations ... 1960 ... Spherical, skin bluish, flesh dark red and very mildly acid, quality good.University of Saskatchewan fruit introductions 1959-1960, p9
• C59-355 Zeta ... Sapa x Oka Mixed open pollinations ... 1960 ... Spherical, skin bluish, flesh dark red and very mildly acid, quality good.University of Saskatchewan fruit introductions 1959-1960, p9

Taxonomy context: No family-tree context surfaced yet.

Related cultivars mentioned in source context