Hort Series #246

Principal Investigators: Jonathan R. Schultheis, Professor and Extension Specialist, Department of Horticultural Science, NC State University; Annette L. Wszelaki, UT Vegetable Extension Specialist, Department of Plant Sciences, University of Tennessee; Travis Birdsell, County Extension Director and Extension Agent, Agriculture, Ashe County Center, Jefferson, NC; Stuart W. Michel, Research Technician, Department of Horticultural Science, NC State University; Brandon K. Parker, Research Associate, Department of Horticultural Science, NC State University; Baker E. Stickley, Research Assistant, Department of Horticultural Science, NC State University

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Acknowledgements

We gratefully acknowledge the assistance of Tracy Taylor (Superintendent) and John Council (Horticulture Supervisor), Upper Mountain Research Station, Laurel Springs, NC, as well as Brooke Emory (UT Research Technician) and the personnel at the research station for their help in establishing, maintaining, and harvesting the 2023 cultigen evaluation study. The cooperation and support of HM Clause, Rupp Seeds, Johnny’s Seeds, Lark Seeds, Sakata, Seneca, and Hollar Seeds was also appreciated. We also want to thank Joy Smith for performing the statistical analysis and aiding in the interpretation of the data collected from this study. This study was funded in part by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2020-51181-32139 (CucCAP).

Disclaimer

This publication presents data from the pumpkin cultigen evaluation study conducted during 2023. Information in this report is believed to be reliable but should not be relied upon as a sole source of information. Limited accompanying detail is included but excludes some pertinent information, which may aid interpretation.

Introduction

North Carolina grew $18.7 million worth of pumpkins in 2022 at an average price of $23.30 per hundredweight (cwt) (2022 State Agriculture Overview). Total harvested acreage was 3,900 acres (ac), an increase of 200 acres from 2021 (3,700 acres). Pumpkin production appears to be increasing in North Carolina, following the trend seen across the U.S. as the demand for pumpkins increases for their ornamental use and the increase in agrotourism (USDA ERS 2015). The majority of production occurs in western NC where the climate and soils are more favorable.

In 2023, Dr. Schultheis and Annette Wszelaki and their teams in the Horticulture Department at NC State and Plant Sciences Department at the University of Tennessee conducted a cultigen evaluation study of 69 carving pumpkins, specialty pumpkins, and gourds in replicated and unreplicated plots. These cultigens were evaluated for yield and quality characteristics that include but are not limited to: shape, suturing, texture, and length and diameter. The materials and methods, results, and representative photos follow.

Materials and Methods

Field Preparations

The field planting site was located at the NCDA&CS Upper Mountain Research Station in Laurel Springs, NC. Gly Star Original Herbicide at a rate of 32 oz/ac was sprayed as a burn-down on 6 April 2023. The field was plowed on 22 May 2023 and black plastic mulch was laid on 25 May 2023.

Planting

The pumpkin entries were planted 14 June 2023. A total of 69 pumpkin cultigens were evaluated, with 31 jack o’ lantern or traditional carving type pumpkins in a replicated trial, and 18 specialty type pumpkins and 20 gourds in un-replicated, observational plots. The study used a randomized complete block design (RCBD) with 4 replications. Each plot measured 18 feet long with 10 feet between plots. The jack type and specialty type pumpkins had an in-row spacing of 3 feet between plants for a potential total of 6 plants per plot and the gourds had an in-row spacing of 1.5 feet between plants for a potential total of 12 plants per plot.

Pesticides

A complete list of the herbicides, fungicides, and insecticides used in this study is provided in Table 1. These products are registered for use in this crop and were applied according to labeled rates that can be referenced in the 2023 North Carolina Agriculture Chemical Manual.

Weather

The weather at the Upper Mountain Research Station in Laurel Springs, NC was generally favorable with a few periods of rainfall over 2 inches in June and July (Figure 1). The temperature was fairly consistent throughout the growing season with averages temperatures in the 60’s and low 70’s. Temperatures were relatively cool the first three weeks of the growing season with lows dipping to 39°F.

Harvest and Data Collection

The gourds were harvested on 13 September 2023 (91 days after planting) and the carving and specialty pumpkins were harvested on 14 September 2023 (92 days after planting). Each pumpkin in the carving and specialty categories was weighed and counted. Ten representative gourds from each plot were weighed and all fruit were counted from those plots. Length and diameter measurements were taken on 3 pumpkins per plot for the carving and specialty pumpkins. Shape, suturing, texture, handle width, handle attachment, and handle length ratings were taken as an average of all of the fruit in a plot. Quality data were not collected for the gourds.

Results

Four cultigens are included in quality evaluations but not yield due to issues with plant stand: ‘HSC 151’ from Rupp Seeds, ‘Kakai’ from Johnny’s Seeds, ‘Porcelain Doll (Improved)’ from Lark Seeds, and ‘Porcelain Doll (Original)’ from Rupp and Johnny’s Seeds.

Yield and Average Fruit Weight Per Size Category

Pumpkin cultivars were divided into the following size categories for yield analysis based on marketed average fruit size: Pie (<5.0 lb), Small (5.0-10.0 lb), Large (13.1-17.0 lb), Extra-Large (17.1-22.0 lb), and Jumbo (>22.0 lb). Only one cultigen, ‘HSC 151’, would have been classified as a Medium size (10.1-13.0 lb), but was not included in yield analysis due to inferior plant stand.

Pie Specialty Pumpkins (<5.0 lb)

‘Blaze’ from Hollar Seeds was the only entry in the Pie size category, with an average fruit weight of 3.7 lb. A total of 37,490 lbs per acre of mature fruit were harvested, and 8,416 lb of immature fruit were harvested (Table 2). ‘Blaze’ produces orange fruit with yellow stripes, shapes are round and slightly flattened.

Pie and Small Jack O’Lantern Pumpkins (2.5-10.0 lb)

Four entries were evaluated in the “Small” size category. ‘Fort Knox’ from Rupp Seeds had the highest yield of the four cultigens at 32,065 lb/ac (Table 3). ‘Yosemite’ from Rupp Seeds had the greatest average fruit weight in this category at 6.8 lb. ‘Field Trip’ from HM Clause and ‘RPX 6201’ from Rupp Seeds were also included in this category, yielding 26,717 lb/ac and 21,713 lb/ac, respectively. ‘RPX 6201’ yielded many smaller fruit compared to other entries in this category, with an average fruit weight of 2.9 lb and yielding 7,442 fruit per acre. The average fruit weight across all four cultigens in this size category was 5.6 lb. All entries in this category had orange fruit.

Large Pumpkins (13.1-17.0 lb)

Four entries were evaluated in the “Large” size category. ‘Hermes’ from HM Clause had the highest yield and the greatest average fruit weight of the four cultigens at 53,803 lb/ac and 16.4 lb (Table 4). ‘Abominable’ from Seneca had the greatest number of fruit per acre in this category at 3,872 fruit, as well as the smallest average fruit weight at 13.1 lb. ‘Sand Ghost’ from Lark Seeds and ‘Skidoo Gold’ from Rupp Seeds were also included in this size category, yielding 48,327 lb/ac and 47,093 lb/ac, respectively. The average fruit weight across all four cultigens in this size category was 15.0 lb. ‘Hermes’ and ‘Skidoo Gold’ produce orange fruit, while ‘Abominable’ has white fruit and ‘Sand Ghost’ has buff fruit.

Extra-Large Pumpkins (17.1-22.0 lb)

Nine entries were evaluated in the “Extra-Large” size category. ‘The Boss (JPN 17-4448)’ from Johnny’s Seeds had the highest yield of the nine cultigens at 62,121 lb/ac (Table 5). ‘Falcon’ from Lark Seeds ranked second for yield at 55,499 lb/ac and had the greatest average fruit weight in this size category at 26.0 lb. ‘Orange Sunrise’ from HM Clause and ‘Bayhorse Gold’ from Rupp Seeds ranked third and fourth for yield at 54,813 lb/ac and 53,458 lb/ac, respectively. ‘Garnett Gold’ from Rupp Seeds had the lowest average fruit weight in this size category at 17.3 lb and the greatest amount of immature fruit at harvest, indicating this may be a later-maturing cultigen. ‘Lemonade’ from HM Clause, ‘Dutchess’ from Johnny’s Seeds, ‘Carbonato Gold’ from Rupp Seeds, and ‘Thumpkin’ from Rupp Seeds were also included in this size category. The average fruit weight across all nine cultigens in this size category was 20.7 lb. All entries in this category produced orange fruit except ‘Lemonade’, which produced yellow fruit.

Jumbo Pumpkins (>22.0 lb)

Nine entries were evaluated in the “Jumbo” size category. ‘Griffin’ from HM Clause had the highest yield of the nine cultigens at 76,805 lb/ac (Table 6). ‘Adonis’ and ‘Cider’ from HM Clause ranked second and third at 75,710 lb/ac and 72,370 lb/ac, respectively. ‘Olympus’ from HM Clause ranked fourth for yield at 65,987 lb/ac and had the highest average fruit weight in this size category at 35.3 lb. ‘Solid Gold’ from Rupp Seeds yielded 56,501 lb/ac mature fruit, ranking fifth, but also yielded 9,093 lb of immature fruit, indicating this may be a later maturing cultigen. ‘Kratos’ from HM Clause, ‘Justify’ from Seneca, ‘XPU7204’ from Sakata, and ‘JPN 17-4445’ from Johnny’s Seeds were also included in this size category. The average fruit weight across all nine cultigens in this size category was 29.7 lb. All entries in this category produced orange fruit except ‘Cider’, which produced buff fruit.

Yield and Average Fruit Weight Across All Size Categories

‘Griffin’ from HM Clause had the highest yield per acre across all 27 replicated entries at 76,805 lb/ac (Table 7). ‘Cider’ from HM Clause had the greatest number of bins per acre at 124.0 bins/acre. ‘Olympus’ from HM Clause had the greatest average fruit weight at 35.3 lb/fruit.

Quality – Carving/Jack-Type Pumpkins

The cultigen with the smoothest fruit texture, corresponding to a low value, out of the 31 jack-type entries was ‘Porcelain Doll (Improved)’ from Rupp and Johnny’s Seeds at 0.9. The cultigen with the roughest texture was ‘Fort Knox’ from Rupp at 6.0 (Table 8). The average fruit texture rating across all entries was 3.5.

The cultigen with the lowest fruit shape rating, corresponding to a flatter shape, was ‘Blaze’ from Hollar Seeds at 1.8 (Table 8). The cultigen with the highest fruit shape rating, corresponding to a taller shape, was ‘Griffin’ from HM Clause at 9.0. The average fruit shape across all 31 entries was 5.1. Another measure of fruit shape was taken through LD measurements. The cultigens with the lowest LD ratio, corresponding to a flatter fruit, were ‘Blaze’ and ‘Porcelain Doll (Improved)’, both having a ratio of 0.6. The cultigen with the highest LD ratio was ‘Griffin’ at 1.3. The average LD ratio across all 31 entries was 0.9.

Cultigens were also rated on fruit suture depth, ranging from little to no sutures, such as ‘Kakai’ from Johnny’s (1.5), to very deep sutures in ‘Porcelain Doll (Improved)’ (9.0). The average fruit suture rating across all 31 entries was 4.0 (Table 8).

The stem or handle of the fruit was also rated for visual strength of attachment, width, and length. The cultigens with the strongest handle attachment were ‘Falcon’ from Lark and ‘Olympus’ from HM Clause, both with a rating of 8.8 (Table 8). The cultigen with the highest rating for handle length and handle width was ‘Thumpkin’ from Rupp at 7.8 and 8.8, respectively.

Specialty Pumpkins – Yield

One specialty-type cultigen, ‘Blue Doll’ from Rupp Seeds, is not included in yield data due to issues with plant stand. Many of the Cucurbita maxima plants emerged but wilted and died about 4 weeks after planting. This was not the case with the Cucurbita pepo species.The specialty-type cultigen that yielded the greatest in pounds per acre was ‘Lunch Lady’ at 71,172 lb/ac (Table 9). The average yield in pounds per acre across all 17 specialty-type cultigens was 34,817 lb/ac. ‘Lunch Lady’ also yielded the greatest number of fruit per acre at 8,712. The average yield in number of fruit per acre across all 17 cultigens was 3,260 no/ac. Specialty-type cultigen entries varied greatly in average fruit size, with ‘JPN 20-5116’ from Johnny’s Seeds averaging 1.5 lb/fruit and ‘Big Moose’ from Seneca and Johnny’s Seeds averaging 45.3 lb/fruit. The average fruit weight across all 17 cultigens was 14.4 lb/fruit.

Specialty Pumpkins – Quality

Specialty pumpkin cultigens varied greatly in color, shape, and texture. Fruit texture ranged from being very smooth, such as ‘Blue Doll’ from Rupp and ‘Long Island Cheese’ from Johnny’s, to rough and warty, such as ‘Fright’ and ‘Red Warty Thing’ from Rupp and ‘Galeux D Eysines’ from Johnny’s. The average fruit texture rating across all 18 specialty entries was 3.6 (Table 10). Fruit shapes ranged from being mostly flat, such as ‘Flat Stacker’ from Johnny’s at 1.0, to round-tall such as ‘Fright’ from Rupp at 6.0. The average fruit shape rating across all 18 entries was 2.5. LD ratios also varied widely in the specialty-type pumpkins, ranging from ‘Flat Stacker’ at 0.4 to ‘Lunch Lady’ at 1.79.

Gourd Pumpkins

The gourd-type cultigen that yielded the greatest in pounds per acre was ‘Blanco’ from Seneca Seeds at 16,988 lb/ac (Table 11). The average yield in pounds per acre across all 20 gourd-type cultigens was 4,508 lb/ac. The cultigen that yielded the greatest in number of fruit per acre was ‘Daisy Gourd’ from Johnny’s Seeds at 47,916 no/ac. The average yield in number of fruit per acre across all 20 cultigens was 17,799 no/ac. Gourd-type cultigen entries also varied greatly in average fruit size, with ‘Blanco’ averaging 7.0 lb/fruit and smaller gourd mixes such as ‘Daisy Gourd’ from Johnny’s and ‘Galaxy of Stars’ and ‘Small Formula Blend’ from Rupp each averaging 0.5 lb/fruit. The average fruit weight across all 20 cultigens was 1.9 lb/fruit.