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Publication #HS1298

University of Florida Potato Variety Trials Spotlight: 'Harley Blackwell'1

Rodrick Z. Mwatuwa, Christian T. Christensen, Pam Solano, Kathleen G. Haynes, and Lincoln Zotarelli2

General Comments

‘Harley Blackwell’ is a potato variety that is commonly grown for the potato chip market. It was selected from the progeny of a cross between B0155-24 and B9935-8 and tested under the pedigree B0564-8. It was released and named jointly by the Agricultural Research Service, the United States Department of Agriculture, the Agricultural Research Service of North Carolina, the Agricultural Experiment Stations of Virginia, New Jersey, Pennsylvania, Florida, and New York, and the Maine Agricultural and Forest Experiment Station in 2000. Tuber production and quality results provided in this spotlight are summarized from various variety trials conducted at the UF/IFAS Hastings Agricultural Extension Center between 1998 and 2016.

General Characteristics

‘Harley Blackwell’ tubers are mostly round with a white flesh color (Figure 1). According to Florida’s rating codes for potato tuber characteristics (Table 1), the tubers have a good appearance with buff skin color, netted skin texture, and intermediate to shallow eye depth (Table 3). ‘Harley Blackwell’ demonstrates high yield potential under Florida production conditions (Tables 2 and 3). On average, marketable yield is 274 cwt/acre with 83% of the tubers produced found between A1 and A3 tuber size classification and low incidence of internal defects like internal heat necrosis. The variety has a medium to high specific gravity of 1.074 (Table 2).

Figure 1. 

Typical tuber and internal flesh color of ‘Harley Blackwell’ potato variety.


Credit:

Kathleen Haynes, UF/IFAS


[Click thumbnail to enlarge.]

Diseases

‘Harley Blackwell’ is resistant to race A of the golden nematode (Globodera rostochiensis) and internal heat necrosis. It is susceptible to Verticillium wilt (Verticillium albo-atrum and Verticillium dahliae) and late blight (Phytophthora infestans). It is moderately susceptible to early blight (Alternaria solani), with intermediate resistance to common scab (Streptomyces scabies), and some tolerance to powdery scab (Spongospora subterranea f. sp. subterranea). The standard UF/IFAS Extension-recommended disease and weed control program described under “Potato Production” (Chapter 13 of the Vegetable Production Handbook for Florida http://edis.ifas.ufl.edu/cv131) should be followed.

Season Length and Growth

‘Harley Blackwell’ is an early to medium maturing variety. Season length was 101 days on average from planting to harvest. This depended on weather conditions during the growing season. Late in the season tuber size should be closely monitored to harvest tubers with marketable size. Soil moisture should be managed late in the season to avoid high soil moisture conditions that cause enlarged lenticels, which are sites of entry for decay organisms.

Fertilization

UF/IFAS trial plots are normally fertilized with 200 to 230 lb/A of N. The first application of 100 lb/A of N (granular) is typically incorporated in the bed 2 to 5 days prior to planting, followed by one or two side dress fertilizer applications at emergence and/or at tuber initiation. Phosphorus and potassium applications follow the UF/IFAS guidelines described in Liu et al. (2016) and normally range between 45 to 100 lb/A of P2O5 and 170 to 235 lb/A of K2O.

Planting

A seed piece of 2 1/2 to 3 oz is recommended for planting. This variety should be planted with 40 inches between rows and 8 inches between plants, at 3 to 4 inches deep. A seed rate of 2,000 to 3,000 lb/acre of seed is expected.

Other Information

For additional information on cultivation, weed and disease management see the Potato Production chapter of the Vegetable Production Handbook available at http://edis.ifas.ufl.edu/cv131.

References

Hutchinson, C. M., J. M. White, D. M., Gergela, P. A. Solano, K. G. Haynes, R. Wenrich, and C. S. Lippi. 2003. “Performance of chip processing potato varieties in northeastern Florida.” HortTechnology, 13(4), 706–711.

Liu, G., E.H. Simonne, K.T. Morgan, G.J. Hochmuth, M. Ozores-Hampton, and S. Agehara. 2016. “Fertilizer management for vegetable production in Florida.” In: Vegetable Production Handbook of Florida 2016–17. J.S. Freeman et al. (eds). Farm Media Journal. p.3–10.

Navarre R. and M. Pavek. 2014. The Potato Botany, Production and Uses. CABI.

Sisson, J.A. and G.A. Porter. 2002. "Performance evaluations of potato clones and varieties in the northeastern states-1999." Maine Agr. For. Expt. Sta., Misc. Publ. 751.

USDA ARS. 2016. Harley Blackwell: Naming and Release Of the ‘Harley Blackwell’ Potato Variety. https://www.ars.usda.gov/Services/Docs.htm?docid=19468. Accessed on 08/05/2016

Zotarelli, L., J. P. Dittmar, P. D. Roberts, P. Stansly, H. A. Smith, and S. E. Webb, 2016. Chapter 13. Potato Production. Vegetable Production Handbook for Florida, 2015–2016 Edition. HS733. Gainesville: University of Florida Institute of Food and Agricultural Sciences. http://edis.ifas.ufl.edu/cv131

Tables

Table 1. 

Florida rating codes for potato vine maturity and tuber characteristics.

Tuber Characteristics1

Rating

Code

Vine

Maturity

Internal

Flesh Color

Skin

Color

Skin

Texture

Tuber

Shape

Eye

Depth

Overall Tuber

Appearance

1

dead

white

purple

partial russet

round

very deep

very poor

2

+-

cream

red

heavy russet

mostly round

--

--

3

yellow and dying

light yellow

pink

moderate russet

round to oblong

deep

poor

4

+-

medium yellow

dark brown

light russet

mostly oblong

--

--

5

moderately senesced

dark yellow

brown

netted

oblong

intermediate

fair

6

+-

pink

tan

slightly netted

oblong to long

--

--

7

starting to senesce

red

buff

moderately smooth

mostly long

shallow

good

8

+-

blue

white

smooth

long

--

--

9

green and vigorous

purple

cream

very smooth

cylindrical

very shallow

excellent

1 Adapted from Hutchinson, C.M., et al. (2003) and Sisson, J.A. and G.A. Porter (2002)

Table 2. 

Summary of production statistics and specific gravity of ‘Harley Blackwell’ grown at the UF/IFAS Hastings Agricultural Extension Center, Hastings, FL from 1998 to 2016, excluding 2001.

Year

Total Yield (cwt/ac)

Marketable yield (cwt/ac)

% of STD

Standard

Size Class (Distribution by class %)3

Range %

Specific Gravity

C

B

A1

A2

A3

A4

A1 to A3

% Culls

1998

390

307

84

Atlantic

0

22*

46

25

7

0

79

14

1.072

1999

384

342

97

Atlantic

0

11*

79

10

0

0

89

5

1.065

2000

290

254

73

Atlantic

0

13*

39

30

18

0

88

8

1.073

2002

256

235

83

Atlantic

0

6*

52

35

7

0

94

3

1.076

2003

416

344

86

Atlantic

0

14*

39

30

16

1

85

3

1.075

2004

347

282

86

Atlantic

11

8

51

25

5

0

81

1

1.087

2005

339

290

102

Atlantic

1

13

69

15

2

0

86

0

1.083

2006

401

333

89

Atlantic

1

14

74

10

1

0

84

1

1.087

2007

359

303

82

Atlantic

2

12

65

16

5

0

86

2

1.075

2008

341

279

98

Atlantic

3

14

57

17

11

0

84

3

1.079

2009

356

288

105

Atlantic

2

11

67

12

8

0

87

8

1.066

2010

367

253

93

Atlantic

4

24

65

5

2

0

72

5

1.072

2011

331

278

106

Atlantic

3

11

63

17

6

0

86

3

1.074

2012

363

300

70

Atlantic

2

9

57

16

15

0

88

7

1.074

2013

314

282

110

Atlantic

2

7

59

18

14

0

92

2

1.071

2014

295

192

85

Atlantic

5

25

60

6

4

0

70

7

1.068

2015

279

201

79

Atlantic

3

15

64

10

8

0

82

13

1.067

2016

263

167

61

Atlantic

9

23

56

6

6

0

67

6

1.071

Average

338

274

88

 

3

14

59

17

8

0

83

5

1.074

1 Marketable yield: Sum of size classes A1 to A3.

2 Size classes: C = 0.5 to 1.5 inches, B = 1.5 to 1 7/8 inches, A1 = 1 7/8 to 2.5 inches, A2 = 2.5 to 3.25 inches, A3 = 3.25 to 4 inches, A4 >4 inches;

3 Size distribution by class: Class (wt)/(Total Yield [wt] – culls [wt])

n.a. = not available

* Classification = <1 7/8 inches (C and B included in this classification)

Table 3. 

Vine maturity, tuber characteristics, and internal tuber defects of ‘Harley Blackwell’ potato variety grown at the UF/IFAS Hastings Agricultural Extension Center, Hastings, FL from 1998 to 2016, excluding 2001.

Year

Vine Maturity (vine kill)

Tuber Characteristics1

Internal Defects2

Internal Flesh color

Skin Color

Skin Texture

Tuber Shape

Eye Depth

Overall Appearance

HH

BR

CRS

IHN

1998

0

0

8

7

3

6

7

0

0

0

0

1999

0

0

8

5

2

4

6

0

0

0

0

2000

0

0

6

5

2

6

6

0

0

0

0

2002

2

2

7

6

2

7

7

0

0

0

1

2003

5

1

6

5

2

6

7

12

0

0

0

2004

4

1

7

5

2

7

7

0

0

0

0

2005

6

1

6

5

2

7

7

0

0

0

0

2006

*

1

6

6

3

6

6

0

0

0

0

2007

6

2

6

5

3

5

7

0

0

0

0

2008

5

2

7

5

2

6

7

0

0

0

0

2009

3

1

6

5

3

4

6

1

0

0

0

2010

7

1

6

5

3

6

7

2

0

0

1

2011

3

1

6

5

2

5

7

0

0

11

2

2012

5

2

6

5

3

5

6

1

0

0

1

2013

5

1

6

5

3

4

6

2

0

0

2

2014

2

1

7

5

3

5

7

0

0

0

0

2015

6

1

9

8

2

7

8

0

2

0

0

2016

7

1

6

7

2

7

7

0

0

0

0

Average

4

1

7

5

2

6

7

1

0

1

0

1 See rating system outlined in Florida Rating Code Table (Table 1).

2 Percent tuber defects. HH = hollow heart, BR = brown rot, CRS = corky ring spot, IHN = internal heat necrosis.

*data not available

Footnotes

1.

This document is HS1298, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date May 2017. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Rodrick Z. Mwatuwa, research assistant; Christian T. Christensen, postdoctoral research associate, Pam Solano; biological scientist; Genetic Improvement of Fruits and Vegetables Laboratory, USDA-ARS, Beltsville, MD; Lincoln Zotarelli, assistant professor; Horticultural Sciences Department, UF/IFAS Extension, Gainesville, FL 32611.


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U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.