Cool soil Increases potato (Solanum tuberosum) tuber number in multiple varieties and alters skin color intensity of ‘Red Norland’ and ‘Adirondack Blue’

Authors: Bethke, Paul

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2023
Publication Date: 7/1/2023
Citation: Bethke, P.C. 2023. Cool soil Increases potato (Solanum tuberosum) tuber number in multiple varieties and alters skin color intensity of ‘Red Norland’ and ‘Adirondack Blue’. American Journal of Potato Research. (2023) 100:79-86. https://doi.org/10.1007/s12230-022-09901-3.
DOI: https://doi.org/10.1007/s12230-022-09901-3

Interpretive Summary: Yield and quality of the potato crop are strongly influenced by environmental conditions. Past research has shown that elevated soil temperature often reduces yield and quality. The effects of cool soil temperature on crop value are less well understood. Chip and fresh market potato varieties were grown in a greenhouse with 22°C days and 18 °C nights. Shortly after emergence, soil temperature in some pots was lowered to approximately 10-14 °C using cooling coils wrapped around individual pots. Soil temperature of controls was 17-21 °C. Tuber number with cool soil averaged 3.2 times that of controls. Total yield, however, was comparable between the two treatments. Compared to ambient temperature controls, skin color of the Red Norland variety was lighter red and skin color of the Adirondack Blue variety was darker purple with cool soil. Thus, soil temperature influenced the accumulation of pigments in the skin. Overall, the data suggest that cool soil temperature influences characteristics of the harvested crop that are important to potato growers, retailers and consumers.

Technical Abstract: Tuber number, size and quality determine crop value. Elevated soil temperature often reduces potato yield and quality. Effects of cool soil are less well understood. Chip and fresh market potato varieties were grown in a greenhouse with 22°C days and 18 °C nights. Shortly after emergence, soil temperature in some pots was lowered to approximately 10-14 °C using cooling coils wrapped around individual pots. Soil temperature of controls was 17-21 °C. Tuber number with cool soil averaged 3.2 times that of controls. Total yield, however, was comparable between the two treatments. Compared to ambient temperature controls, skin color of ‘Red Norland’ was lighter red and skin color of ‘Adirondack Blue’ was darker purple with cool soil. Thus, soil temperature influenced the biochemistry underlying accumulation of anthocyanin pigments in the skin. Overall, the data suggest that cool soil temperature influences commercially important characteristics of the harvested crop.