The World of Apples

Apple varieties, United States

GoldRush

A late yellow apple of the Purdue–Rutgers–Illinois programme, named for its gold colour and "rush" of flavour

History

GoldRush comes from the cooperative scab-resistance breeding programme of Purdue University, Rutgers University and the University of Illinois (PRI)1,2. In 1972, at Urbana, Illinois, the breeders crossed Golden Delicious, as seed parent, with pollen of Co-op 171,3, a PRI selection descended from Winesap that carried scab resistance from Malus floribunda 821 and resisted three insect pests6. SNP data confirm both parents7, and GoldRush carries one copy of the resistance gene, Vf1,2.

The seedling was planted in May 1973 on the Purdue Horticulture Research Farm at West Lafayette, Indiana, and selected in October 1980 by E. B. Williams1,3. It nearly did not survive: mice girdled both trees in its second test planting, and Jeff Crosby, then a technician in the programme, saved them by inarching2. It went out for advanced testing as Co-op 38 in 19932 and was named that year5; US Plant Patent 9,392 followed in December 19953. The name joins its golden colour to the “rush” of its flavour1,2.

By 2001, Jules Janick of Purdue reported, its strong flavour at harvest and imperfect finish had slowed its acceptance by supermarkets, but it was succeeding in farm markets, where flavour counts for more than looks2.

The fruit

The fruit is medium-sized, 64–76 mm across and ovate1,4. The skin, greenish yellow at harvest and sometimes blushed bronze or red, turns deep yellow in store; it has no wax and conspicuous russeted dots1. The pale yellow flesh is firm, very crisp and medium-coarse, and does not brown1,3; the flavour is complex, spicy and sharply acid at harvest1. In the breeders’ tests after cold storage it was firmer than Golden Delicious (93 against 76 newtons), with more soluble solids and more than twice the acidity1.

It ripens in the last third of October at West Lafayette, and where hard frosts hold off it can be picked in November1,2. The fruit keeps its flavour and crispness for at least seven months at 1 °C1, or eight months or more by Janick’s account2; at Purdue it was rated each year the best apple after storage1,2. It does not turn greasy, but shrivels unless kept humid, though even shrivelled fruit stays crisp1,2.

Growing

The tree is moderately vigorous and slightly upright, with a strong central leader, wide crotch angles and many spurs; its fruit hangs well, with little drop before harvest1. It crops from its second year2 and tends to overbear: thinning is needed for good size, and heavy crops can make it biennial1,2. It flowers late, after Golden Delicious and slightly before Enterprise1, and Janick judged it best suited to areas level with Indiana or further south2.

In greenhouse tests none of races 1 to 5 of the scab fungus sporulated on it1. It is highly resistant to powdery mildew and moderately resistant to fire blight, but as susceptible to cedar-apple rust as Golden Delicious, with severe infection seen in New Jersey1. It is also prone to sooty blotch1 and flyspeck2. GoldRush is diploid7.

Uses

Besides being a winter dessert apple1, GoldRush makes sauce without added sugar, good processed and dried slices, and excellent cider: for three years up to 2001 the winning cider at the Indiana cider contest was a blend made mainly from it2.

Where the sources disagree

  • Its place in the series. Announcing GoldRush with Enterprise, the breeders called them “the eighth and ninth releases” of the programme4; GoldRush’s release paper and Janick’s 2001 account call it the tenth1,2.
  • Season. Three and a half to four weeks after Delicious in the release paper, which gives both 24–31 and 20–30 October1; three weeks in the patent’s description but three and a half in its claim3.

Family tree

Parents, grandparents and great-grandparents, as the entries in the atlas record them.

  • GoldRush United States, 1972
Golden Delicious GoldRush
Where GoldRush came from. The lines lead to its parents: Golden Delicious (United States).

Sources

  1. 'GoldRush' Apple, Jeffrey A. Crosby, Jules Janick, Paul C. Pecknold, Joseph C. Goffreda and Schuyler S. Korban, HortScience 29(7): 827–828; reproduced on the PRI programme's website, Purdue University, 1994. Supports: named "to emphasize its golden ground color and bronze blush combined with its 'rush' of flavor"; "the tenth apple cultivar" of the programme; complex, rich, spicy flavour with high acidity and sweetness, acidity moderating in cold storage; flavour and crisp texture kept for at least 7 months at 1 °C; "rated consistently as the highest quality apple after storage" of all tested at Purdue; little cuticular wax and no greasiness after 7 months, shrivelling to be prevented by managing moisture, the flesh staying crisp even when shrivelled; thinning needed for large fruit; the seedling planted in May 1973 in the HE block of the Purdue Horticulture Research Farm, West Lafayette (row 4, tree 16; PRI 2750-6), from a cross made in 1972 at Urbana of Golden Delicious (seed parent) with Co-op 17 (PRI 1689-110) (pollen parent); Vf from Malus floribunda 821; selected in October 1980 by E. B. Williams; released for testing as Co-op 38; fruit 64–76 mm, ovate, greenish yellow with an occasional bronze to red blush at harvest, deep yellow in storage; skin nonwaxy, with conspicuous russeted lenticels like Midwestern-grown Golden Delicious; flesh medium-coarse-grained, firm, crisp, pale yellow, non-browning; flavour complex, spicy and sprightly acid at harvest; maturity 3.5 to 4.0 weeks after Delicious, 24 to 31 October at Lafayette in the text and 20 to 30 October in the formal description; Table 1 (after cold storage at 0 °C): firmness 93 N against 76 N, soluble solids 13.7 against 12.2, titratable acidity 0.61 against 0.28 g malic acid per 100 ml for Golden Delicious; tree slightly upright, moderately vigorous, with a strong central leader, wide crotch angles and heavy spurring, fruit borne singly on short spurs and not prone to preharvest drop, some biennial tendency if overcropped; flowering after Golden Delicious and slightly earlier than Enterprise; no sporulation after repeated greenhouse inoculation with scab races 1 to 5; moderate resistance to fire blight; high resistance to powdery mildew; cedar-apple rust susceptibility similar to Golden Delicious, with severe infection in New Jersey; susceptible to sooty blotch; a winter dessert apple.
  2. 'GoldRush' Apple, Jules Janick, Journal of the American Pomological Society 55(4): 194–196, 2001-10. Supports: the name from its "old-gold" colour and a "rush" of flavour; ripening at the end of October in West Lafayette, but pickable in November without hard freezes, and so best adapted to areas level with or south of Indiana; field immunity to scab, reasonable resistance to mildew and fire blight, but subject to sooty blotch and flyspeck; strong central leader growth with moderate vigour; "highly precocious", fruiting in the second leaf; high acidity and sugar, the acidity mellowing in storage for "up to 8 months or longer"; crisp, not greasy, but may shrivel at low humidity; "consistently classified as the best tasting apple" in Purdue's winter and spring evaluations; a tendency to overbear, needing thinning; an excellent processed product: sauce needing no added sugar, slices holding up extremely well, good dried slices; excellent for cider, the winning cider in the Indiana Cider contest over the last three years a blend in which GoldRush predominated; a product of the PRI programme; "the tenth release"; heterozygous for Vf; the seedling planted in May 1973 at the Purdue University Horticulture Farm, from Golden Delicious (seed parent) and Co-op 17 (pollen parent); selected in 1980 by E. B. Williams and placed for advanced testing as Co-op 38 in 1993; the two trees of the second test plantings girdled by mice and saved by inarching by Jeff Crosby, then a technician in the programme; acceptance by supermarkets slowed by its strong flavour at harvest and lack of finish, but success in retail farm markets.
  3. Apple tree 'Co-op 38' (US Plant Patent 9,392), Jeffrey A. Crosby, Jules Janick, Edwin B. Williams, Joseph Goffreda, Daniel F. Dayton and Paul C. Pecknold, Purdue Research Foundation; Google Patents, 1995-12-05. Supports: "Co-op 38, also known as Goldrush"; flesh "Medium coarse grained, firm, very crisp and breaking"; the cross of Golden Delicious (seed parent) and Co-op 17, given as "PRI 1661-1" (pollen parent), made in 1972 at Urbana, Illinois; the seedling planted in May 1973 in the HE block of the Purdue Horticulture Research Farm (row 4, tree 16; PRI 2750-6) and discovered in October 1980; maturity 20 to 30 October at West Lafayette, "three weeks after Delicious" in the description and about three and a half weeks in the claim; quality kept for at least 7 months at 1 °C; application filed 2 June 1993, granted 5 December 1995.
  4. 'Enterprise' and 'GoldRush,' Two New Disease-Resistant Cultivars, J. A. Crosby, Jules Janick, P. C. Pecknold, S. S. Korban, S. M. Ries, J. Goffreda and A. Voordeckers, Fruit Varieties Journal 48(1): 43, American Pomological Society, 1994. Supports: Enterprise and GoldRush "the eighth and ninth releases" of the cooperative programme of Purdue, Rutgers and Illinois, each with the Vf gene from Malus floribunda 821; GoldRush formerly Co-op 38 (PRI 2750-6), "a medium sized apple" maturing 3.5 weeks after Delicious, 20 to 30 October at Lafayette, Indiana.
  5. About PRI, PRI disease resistant apple breeding program (Purdue University, Rutgers University and the University of Illinois), Purdue University. Supports: the cooperative programme of Purdue, Rutgers and Illinois, begun in 1945 to breed apples resistant to scab; GoldRush named in 1993.
  6. Plant Inventory No. 204, Part II (Plant Materials Introduced July 1 to December 31, 1995), pp. 126 and 163: Co-op 17 and Goldrush, R. A. Norris (ed.), USDA Agricultural Research Service, 1996-08. Supports: PI 589953, Co-op 17 (p. 126): from an open-pollinated Winesap seedling (Illinois #2) and PRI 668-100, whose recorded ancestry includes Golden Delicious and "F2" 26829-2-2; scab resistance from M. floribunda 821; resistance to apple maggot, plum curculio and red-banded leafroller (Goonewardene); PI 590218, Goldrush (p. 163): "Golden Delicious x Coop 17[PRI 1689-100]", "Cross made 1972; selected 1980 by E.B. Williams".
  7. Using whole-genome SNP data to reconstruct a large multi-generation pedigree in apple germplasm, Hélène Muranty and others, BMC Plant Biology 20: 2, with Additional files 1 and 3, 2020. Supports: Table S3: Goldrush inferred as the offspring of Co-op 17 and Golden Delicious (158 Mendelian errors, under the threshold of 600), both parents agreeing with the literature; Table S1: Goldrush diploid (2n).

All 235 varieties from United States