Growth Dynamics and Yield Assessment of Five Jerusalem Artichoke Varieties in Wooster, Ohio

Jerusalem artichoke (Helianthus tuberosus L.), or sunchoke, is a resilient, low-input crop with potential for biomass and tuber production. However, a comprehensive understanding of varietal performance in specific environments like Ohio is essential to unlock its full agricultural potential. This 2024 study evaluated the growth and yield performance of five sunchoke varieties in Ohio:

• Beaver Valley
• Dwarf Sunray
• Jack's Copperclad
• Supernova
• White Fuseau

Plant height, tuber yield parameters, and morphological characteristics were assessed during one growing season. We observed differences in yield and growth habits, providing preliminary insights on the most suitable varieties for Ohio farms and gardens. Dwarf Sunray demonstrated the fastest growth, while Jack's Copperclad exhibited the slowest growth rate. White Fuseau produced the highest tuber count and weight, yielding approximately nine times more tuber weight than Jack's Copperclad. The varieties also showed differences in branching patterns, flowering times, tuber shapes, and tuber colors. This study provides useful preliminary information for selecting the Jerusalem artichoke varieties best suited for cultivation in Ohio, offering insights for further research and practical applications.

Sunchoke: A Native Plant with Great Potential

Sunchoke, a native North American plant with origins in the Great Lakes, Ohio River, and Mississippi River valleys (Swanton et al., 1992), belongs to the Asteraceae family and possesses great adaptability to diverse environmental conditions (Rossini et al., 2019). Sunchoke is now cultivated worldwide in diverse climates.

The plant's growing season typically extends from mid-April to mid-November when the tubers are ready to be harvested. Sunchokes are appealing to Ohio growers and homeowners due to their multiple uses as food, pollinator habitat, and biofuel production. Their high biomass yields, with aerial dry matter ranging from 8.9–22.3 tons per acre⁻¹, and tuber dry matter between 4.5–13.4 tons per acre⁻¹, make them an attractive option for sustainable agriculture (Liu et al., 2012). Sunchokes exhibit resistance to weeds, pests, diseases, and drought. They also require minimal fertilization, making them a promising crop for marginal lands.

At the end of the growing season, sunchokes produce tubers known for their high inulin content, containing 0.5–0.86 lb of inulin per lb of dry matter along with an 80%–97% total sugar content (Baldini et al., 2004). Inulin is classified as a pre-biotic compound and its consumption is beneficial for managing type 2 diabetes.

Despite the growing interest in sunchokes, their availability remains limited, particularly in gardening and agricultural supply channels. Most sunchoke varieties are only accessible through limited platforms, where they are often sold without detailed growth habit or environmental adaptability information. This lack of accessible knowledge about cultivation practices and performance creates a barrier for potential growers, especially in regions like Ohio. Without comprehensive data on how these varieties develop under specific local conditions, many gardeners and farmers are uncertain about how to optimize their cultivation efforts.

Sunchoke Growth

Several varieties of sunchoke (Beaver Valley, Dwarf Sunray, Jack's Copperclad, Supernova, and White Fuseau), were ordered online from small permaculture farms and then evaluated in raised beds in Wooster, Ohio during the 2024 growing season. All sunchoke tubers were shipped by mail during early spring 2024. They arrived in great condition, ready to be planted. Seed tubers were germinated in a greenhouse and young plants were transplanted during early May into raised beds measuring 6 feet wide, 4 feet long, and 1.6 feet high. Plants were fertilized every two weeks with water-soluble fertilizer [28-8-16; nitrogen, phosphorus, and potassium (NPK)]. The tubers were harvested in October 2024 and stored in a cooler.

Jack's Copperclad exhibited the lowest overall growth rate. Dwarf Sunray, Supernova, and White Fuseau showed a higher growth rate throughout the season, suggesting potential for applications where taller plants are advantageous, such as biomass production. Beaver Valley displayed an intermediate growth rate between these two groups.

The observed variations in plant height among sunchoke varieties have practical implications for cultivation practices. Plant spacing requirements will differ significantly based on variety and final plant size. Taller varieties like Dwarf Sunray, Supernova, and White Fuseau will require wider spacing to ensure adequate light and airflow between plants. Shorter varieties such as Jack's Copperclad and Beaver Valley can be planted closer together to maximize land-use efficiency. Height differences also influence plant stability. Taller varieties may require staking or other support systems to prevent wind damage or toppling, which could reduce yield or harm plants. Furthermore, plant height affects harvest planning and techniques. For example, the timing and methods used for stem cutting may need to be adjusted depending on the variety's height.

These considerations are critical for farmers and gardeners when selecting and planning cultivation strategies for sunchoke varieties to achieve optimal results in terms of plant health, yield, and ease of management.

Tuber Yield Parameters

The yield of sunchoke (total number of tubers and total tuber weight) per plant varied among different varieties. The results revealed variations in tuber number among the different sunchoke varieties (Table 1). White Fuseau exhibited the highest tuber count with an average of 225 tubers per plant. This was followed by Supernova with 195 tubers, Dwarf Sunray with 178 tubers, Jack's Copperclad with 45 tubers, and Beaver Valley with 42 tubers per plant. In addition, a considerable range in total tuber weight was observed, with Jack's Copperclad producing an average of 1.1 lb of tubers per plant, and Beaver Valley producing 1.9 lb of tubers per plant, while Supernova produced 13.6 lb of tubers per plant, Dwarf Sunray produced 16.3 lb of tubers per plant, and White Fuseau yielded the most with 17.4 lb of tubers per plant. This demonstrates an approximately 16-fold difference in yield between the lowest-producing (Jack's Copperclad) and the highest-producing (White Fuseau) sunchoke varieties.

AVERAGE TUBER WEIGHT

When looking at the average tuber weight, a slight difference was observed between Beaver Valley and Jack's Copperclad—two varieties producing a similar number of tubers. The average tuber weight (0.057 lb/tuber) of Beaver Valley was higher than the average tuber weight (0.027 lb/tuber) of Jack’s Copperclad. High-yielding varieties also displayed some variations in average tuber weight. Supernova and White Fuseau showed similar average tuber weight (0.113 and 0.116 lb/tuber respectively) while Dwarf Sunray had the highest tuber weight (0.149 lb/tuber).

TUBER SIZE AND COLOR

Sunchoke varieties exhibit significant differences in tuber shape, size, and color (Table 1, Figure 2, Figure 3). Jack's Copperclad and Beaver Valley produce reddish tubers, with Jack's Copperclad having a darker red hue. White Fuseau, Supernova, and Dwarf Sunray develop white tubers. Variations in tuber size and color are linked to differences in their root systems. Varieties with denser, more extensive root systems like White Fuseau, Supernova, and Dwarf Sunray tend to produce white, heavy tubers, while those with less dense root systems, like Jack's Copperclad and Beaver Valley, yield a lower quantity of reddish tubers. These findings align with previous research on the morphological diversity of sunchoke populations (Puttha et al., 2013; Smekalova et al., 2020), highlighting the variability in characteristics across different varieties. Variations in tuber shape and color are important considerations for growers aiming to meet specific market demands or develop varieties for targeted uses. Reddish tubers may appeal to niche markets or specialty culinary applications, while white tubers may be preferred for broader consumer acceptance or industrial uses.

Plant Shape and Flowering Time

The differences in plant height and branching patterns, evidenced in the number of lateral shoots between the sunchoke varieties (Figure 4), present distinct opportunities for gardeners. Shorter and low branching varieties, such as Jack's Copperclad and Beaver Valley, are well-suited for small garden or container cultivation, providing edible and ornamental value without needing much space (Puttha et al., 2013). In contrast, taller varieties with a high number of lateral shoots like Dwarf Sunray, Supernova, and White Fuseau can be used as a backdrop in mixed borders or as temporary screens, adding vertical interest and attracting pollinators with their showy flowers (Smekalova et al., 2020). The denser branching patterns in varieties like White Fuseau and Dwarf Sunray are visually appealing in landscape settings.

The first flowering date differed between the sunchoke varieties. Flowering was monitored from August (first detection) to end of September (last detection). Dwarf Sunray and Supernova were the first to bloom (late June, early July), followed by Beaver Valley (July), Jack's Copperclad (August), and White Fuseau (August–September). Beaver Valley displayed consistent flowering intensity, beginning with 22 flowers and gradually increasing to 38 flowers. In contrast, Dwarf Sunray showed a dramatic surge in flowering, starting with one flower and increasing to 81 flowers, making it a standout ornamental option for late-season gardens. Jack's Copperclad maintained moderate flowering growth, increasing from nine to 25 flowers over the same period. Similarly, Supernova exhibited steady flowering progression, beginning with one flower and ending with 50 flowers. White Fuseau had minimal flowering throughout the season, producing only three flowers by the final week, highlighting its lower ornamental potential compared to the other varieties. These variations in flowering patterns highlight each variety’s unique ornamental potential, allowing growers to choose based on specific aesthetic needs or functional goals.

Conclusion

These five varieties of sunchokes presented many differences in growth patterns, yield, and morphological traits when cultivated in Wooster, Ohio. Dwarf Sunray exhibited the highest growth rate despite being advertised as a dwarf variety, while Jack's Copperclad had the lowest growth rate. Tuber production varied, with White Fuseau yielding the most. Morphological variations were also observed in plant shape, flowering time, and tuber characteristics, such as color. For example, Beaver Valley and Jack's Copperclad produced reddish tubers, while White Fuseau, Dwarf Sunray, and Supernova yielded predominantly white tubers. These findings reflect the diversity within the species and provide valuable insights for selecting suitable sunchoke varieties based on specific agricultural needs and environmental conditions in Ohio.

Additional Resources

• Genetic similarity of the Jerusalem artichoke populations (Helianthus tuberosus L.) collected in Montenegro.
• The complete chloroplast genome of the Jerusalem artichoke (Helianthus tuberosus L.) and an adaptive evolutionary analysis of the ycf2 gene.

References

Baldini, M., Danuso, F., Turi, M. & Vannozzi, G. P. (2004). Evaluation of new clones of Jerusalem artichoke (Helianthus tuberosus L.) for inulin and sugar yield from stalks and tubers. Industrial Crops and Products, 19(1), 25–40.
doi.org/10.1016/S0926-6690(03)00078-5

Liu, Z. X., Spiertz, J. H. J., Sha, J., Xue, S. & Xie, G. H. (2012). Growth and yield performance of Jerusalem artichoke clones in a semiarid region of China. Agronomy Journal, 104(6), 1538–1546.
doi.org/10.2134/agronj2012.0091

Puttha, R., Jogloy, S., Suriharn, B., Wangsomnuk, P. P., Kesmala, T. & Patanothai, A. (2013). Variations in morphological and agronomic traits among Jerusalem artichoke (Helianthus tuberosus L.) accessions. Genetic Resources and Crop Evolution, 60, 731–746.
doi.org/10.1007/s10722-012-9870-2

Rossini, F., Provenzano, M. E., Kuzmanović, L. & Ruggeri, R. (2019). Jerusalem Artichoke (Helianthus tuberosus L.): A versatile and sustainable crop for renewable energy production in Europe. Agronomy, 9(9), 528.
doi.org/10.3390/agronomy9090528

Smekalova, T. N., Lebedeva, N. V. & Novikova, L. Y. (2020). Morphological analysis of Jerusalem artichoke (Helianthus tuberosus L.) accessions of different origin from Vir collection. Proceedings of the Latvian Academy of Sciences, Section B: Natural, Exact, and Applied Sciences, 73(6), 502–512.
doi.org/10.2478/prolas-2019-0077

Swanton, C. J., Clements, D. R., Moore, M. J., & Cavers, P. B. (1992). The biology of Canadian weeds. 101. Helianthus tuberosus L. Canadian Journal of Plant Science, 72(4), 1367–1382.
doi.org/10.4141/cjps92-169