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.
'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.
'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).
'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.
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.
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.
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.
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
Florida rating codes for potato vine maturity and tuber characteristics.
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.
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.