University of Florida Potato Variety Trials Spotlight: 'Peter Wilcox'

Mario H. M. L. Andrade, Rodrick Z. Mwatuwa, Christian T. Christensen, Pam Solano, Kathleen G. Haynes, and Lincoln Zotarelli


Introduction

There are several potato varieties available in the market today. Most of them have been bred or developed in production regions other than Florida. The University of Florida Potato Variety Evaluation Program screens new germplasm from public and private breeding programs and identifies the most promising cultivars for commercial potential considering broad adaptability to Florida climate and conditions and market purpose: processing, fresh-market and specialty-type varieties. Over the years, the UF/IFAS Potato Variety Program has become an important reference to vegetable growers, seed producers, processors, crop insurance agencies, and brokers looking for alternative potato varieties to explore different markets, improved characteristics, and yield. This UF/Potato Variety Trials Spotlight presents a summary of the field evaluation of tuber yield and quality performance of the potato variety 'Peter Wilcox' cultivated in Florida.

General Comments

'Peter Wilcox' is a fresh-market potato variety selected from progeny of a cross between B0810-1 and B0918-5 and tested under the pedigree B1816-5 by K. G. Haynes. It was jointly released by the United States Department of Agriculture, the North Carolina Agricultural Research Service, the Agricultural Experiment Stations of New Jersey, Pennsylvania, Florida, and New York, and the Maine Agricultural and Forest Experiment Station in 2007. 'Peter Wilcox' demonstrates good tuber characteristics and high yields. Yields are slightly lower than the commercial standard 'Red LaSoda' (RLAS). Tuber production and quality results provided in this spotlight are from Florida Potato Variety Trials conducted at the UF/IFAS Hastings Agricultural Extension Center between 2001 and 2019.

General Characteristics

'Peter Wilcox' has a semi-erect plant habit with intermediate foliage. Tubers have a purple and slightly netted skin with a medium-yellow flesh (Figure 1), according to Florida rating codes for potato tuber characteristics (Table 1). The tubers have a fair to good appearance with round to oblong shape and intermediate to shallow eye depth with apical distribution (Tables 1 and 3). The tubers have a low to medium specific gravity of 1.066 (Table 2) with a long dormancy (time required for sprout emergence). Tuber carotenoid concentration was shown to be higher than that for 'Yukon Gold' (Haynes et al. 2015). 'Peter Wilcox' has high yield potential under Florida production conditions with 221 cwt/acre marketable yield and 75% of the tubers produced in tuber size distribution classes A1 and A3 (Table 2).

Figure 1. Typical tuber and internal flesh color of 'Peter Wilcox' potato variety.
Figure 1.  Typical tuber and internal flesh color of 'Peter Wilcox' potato variety.
Credit: Lincoln Zotarelli, UF/IFAS

 

Diseases

'Peter Wilcox' demonstrates no incidence of hollow heart, brown rot, corky ringspot, or internal heat necrosis (Table 3). It is resistant to powdery scab (Spongospora subterranea) and susceptible to late blight (Phytophthora infestans), early blight (Alternaria solani), common scab (Streptomyces scabies), potato virus Y, and potato virus S. The cultivar is highly susceptible to Verticullium wilt (Verticillium albo-atrum and Verticillium dahliae). The standard UF/ IFAS Extension recommended disease and weed control program described under Potato Production (Chapter 14 of the Vegetable Production Handbook for Florida, https://edis.ifas.ufl.edu/cv131) should be followed.

Season Length and Growth

'Peter Wilcox' is a medium-maturing cultivar under Florida growing conditions. Season length was 94 days on average from planting to harvest. This depended on weather conditions during the growing season. The plants should be harvested two to three weeks after vine kill to improve tuber maturation and skin set. Potatoes with proper skin set maintain better skin color, lose less weight in storage, and are more resistant to bruising and soft rot. For more information about vine killing on potatoes, see Potato Vine Killing or Desiccation (Zotarelli et al. 2016). Late in the season, tuber size should be checked regularly in order to harvest tubers with desirable marketable size. Soil moisture should be managed late in the season to avoid high soil moisture conditions that cause enlarged lenticels and delayed skin set.

Fertilization

UF/IFAS trial plots are normally fertilized with 200 to 230 lb/ac of N. The first application of 100 lb/ac of N (granular) is typically incorporated in the bed 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. (2020) and normally range between 45 to 100 lb/ac of P2O5 and 170 to 235 lb/ac of K2O.

Planting

A seed piece of 2.5 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 and weed and disease management, see Potato Production, chapter 14 of the Vegetable Production Handbook, available at https://edis.ifas.ufl.edu/cv131.

References

Haynes, K. G., G. Craig Yencho, M. E. Clough, M. R. Henninger, X. S. Qu, B. J. Christ, et al. 2015. "Peter Wilcox: A New Purple-Skin, Yellow-Flesh Fresh Market Potato Cultivar with Moderate Resistance to Powdery Scab." American Journal of Potato Research 92 (5): 573–581.

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, S. Agehara, and R. Mylavarapu. 2020. Chapter 2. Fertilizer Management for Vegetable Production in Florida. Vegetable Production Handbook for Florida, 2020–2021 Edition. CV296. Gainesville: University of Florida Institute of Food and Agricultural Sciences. https://edis.ifas.ufl.edu/cv296

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.

Zotarelli, L., P. J. Dittmar, P. D. Roberts, J. Desaeger, and B. Wells. 2020. Chapter 14. Potato Production. Vegetable Production Handbook for Florida, 2020–2021 Edition. HS733. Gainesville: University of Florida Institute of Food and Agricultural Sciences. https://edis.ifas.ufl.edu/cv131

Zotarelli, L., S. Sargent, P. Dittmar, and M. Makani. 2016. Potato Vine Killing or Desiccation. HS181. Gainesville: University of Florida Institute of Food and Agricultural Sciences. https://edis.ifas.ufl.edu/hs181

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 russet

--

--

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 et al. (2003) and Sisson and Porter (2002)

Table 2. 

Summary of production statistics and specific gravity of 'Peter Wilcox', a purple-skinned fresh-market potato variety grown at the UF/IFAS Hastings Agricultural Extension Center, Hastings, FL from 2001 to 2019.

Year

Total Yield (cwt/ac)

Marketable yield1 (cwt/ac)

% of STD

Standard

Size Class (Distribution by class %)2

Range %

Specific Gravity

C

B

A1

A2

A3

A4

A1 to A3

Culls

2001

313

259

93

'Red Lasoda'

0

14*

77

8

1

0

86

4

1.069

2002

339

296

87

'Red Lasoda'

0

10*

72

17

1

0

90

3

1.064

2003

461

400

95

'Red Lasoda'

5

5

51

33

6

0

90

4

1.062

2004

330

248

76

'Red Lasoda'

12

12

70

6

0

0

75

1

1.076

2005

272

197

66

'Red Lasoda'

1

23

75

1

0

0

76

5

1.072

2006

333

273

68

'Red Lasoda'

2

15

84

0

0

0

84

3

1.070

2007

354

278

80

'Red Lasoda'

2

19

76

3

0

0

79

0

1.067

2008

256

150

78

'Red Lasoda'

4

35

59

2

0

0

61

3

1.071

2009

287

207

61

'Red Lasoda'

2

13

65

17

3

0

85

20

1.062

2010

286

110

47

'Red Lasoda'

10

50

39

0

0

0

39

3

1.060

2011

351

245

109

'Red Lasoda'

5

21

74

0

0

0

74

10

1.062

2012

311

214

124

'Red Lasoda'

3

17

68

12

0

0

80

15

1.060

2013

229

165

154

'Red Lasoda'

4

17

73

6

0

0

79

10

1.055

2014

339

208

93

'Red Lasoda'

4

32

63

1

0

0

64

4

1.062

2015

109

61

43

'Red Lasoda'

5

35

60

0

0

0

60

7

1.060

2016

282

189

208

'Red Lasoda'

5

26

68

1

0

0

69

3

1.069

2017

262

184

147

'Red Lasoda'

4

22

69

4

1

0

74

7

1,062

2018

265

198

113

'Red Lasoda'

4

18

76

2

0

0

78

4

1.07

2019

333

319

157

'Red Lasoda'

4

12

42

41

0

0

84

4

1.072

Average

301

221

100

'Red Lasoda'

4

22

66

8

1

0

75

6

1.066

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

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

Table 3. 

Vine maturity, tuber characteristics, and internal tuber defects of 'Peter Wilcox', a purple-skinned fresh-market potato variety grown at the UF/IFAS Hastings Agricultural Extension Center, Hastings, FL from 2001 to 2019.

Year

Vine Maturity

Tuber Characteristics1

Internal Defects2

Internal Flesh Color

Skin Color

Skin Texture

Tuber Shape

Eye Depth

Overall Appearance

HH

BR

CRS

IHN

2001

3

4

1

6

3

7

6

0

0

0

0

2002

4

4

1

7

3

7

6

0

0

0

0

2003

8

5

1

5

3

6

6

3

0

0

0

2004

6

4

1

6

3

6

6

1

0

0

0

2005

6

5

1

5

4

5

6

0

0

0

0

2006

8

4

2

6

3

7

6

0

0

0

0

2007

6

4

1

7

4

5

6

0

0

0

0

2008

7

5

1

7

3

6

6

0

0

0

0

2009

6

4

1

6

4

4

6

0

0

0

0

2010

7

4

1

6

4

7

6

0

0

0

0

2011

7

4

1

6

4

3

6

0

0

0

0

2012

9

5

1

6

4

4

6

0

1

0

0

2013

7

3

1

5

2

4

5

0

0

1

0

2014

4

5

1

7

3

4

8

0

0

0

0

2015

5

na3

na

na

na

na

6

0

0

0

0

2016

6

3

1

7

3

7

7

0

0

3

1

2017

7

3

1

6

4

7

6

0

0

0

0

2018

7

4

1

8

3

8

7

0

0

0

0

2019

6

3

1

8

3

8

7

0

0

0

0

Average

6

4

1

6

3

6

6

0

0

0

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.

3 na = data not available