Effect of foliar application of 2,4-D and calcium on four red-skinned potato cultivars

Authors: QIN, RUIJIN - Oregon State University; MOPARTHI, SWARNALATHA - Montana State University; Feldman, Max; CHARLTON, BRIAN - Oregon State University; SATHUVALLI, VIDYASAGAR - Oregon State University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2020
Publication Date: 12/11/2020
Citation: Qin, R., Moparthi, S., Feldman, M.J., Charlton, B.A., Sathuvalli, V. 2020. Effect of foliar application of 2,4-D and calcium on four red-skinned potato cultivars. Agronomy Journal. 113(1):88-89. https://doi.org/10.1002/agj2.20444.
DOI: https://doi.org/10.1002/agj2.20444

Interpretive Summary: As primarily a fresh market product, tuber skin quality and appearance are among the most valued characteristics to consumers of red-skinned potatoes. Skin quality and appearance vary among cultivars and oftentimes agronomic management strategies including chemical and fertilizer application are used to increase the concentration of anthocyanin pigments and reduce the negative impacts of disease and/or color fading that sometimes occur during storage. Scientists at the USDA-ARS laboratory in Wapato, WA in collaboration with researchers at Oregon State University and Montana State University compared the yield and specific gravity of four red-skinned potato cultivars at harvest and assessed colorimetric differences of tuber skin at three different time points during cold storage in response to application of 2,4-D and calcium fertilizer across two field seasons. Results from this study suggest that 2,4-D treatment may improve colorimetric characteristics and decrease the number of over-sized tubers, whereas calcium application had no effect on yield or tuber color but significantly reduced specific gravity across both years. These results support the body of evidence indicating 2,4-D application can be used to improve marketable red-skinned potato yield whereas calcium application may not influence skin color and can decrease tuber specific gravity in soils with adequate calcium supply

Technical Abstract: Application of the plant growth regulator 2,4-dichlorophenoxyacetic acid (2,4-D) and calcium (Ca) is often used to improve the tuber skin quality of red potatoes. Field trials were conducted at Klamath Falls, OR in 2004 and in 2005 to evaluate the effect of foliar applications of 2,4-D and Ca on yield components, specific gravity, and the tuber skin color of four red skinned potato clones (Red LaSoda, Mazama, Cherry Red, Rio Rojo). Skin color was evaluated using a Konica Minolta colorimeter at three time points during storage. Application of 2,4-D and calcium did not significantly affect total tuber yield. However, 2,4-D application decreased the yield of tubers over 284g while increasing the proportion of tubers less than 113g and 170g potato respectively. When compared to untreated potato plants, 2,4-D application resulted in significantly darker tuber skin (lower L values) and increased red color (evidenced by lowered hue angle values). Foliar application of calcium had no effect on the tuber yield and the skin color. Ca addition significantly influenced specific gravity, decreasing solids content across both years. All the potato cultivars in the current study exhibited color fading throughout the storage period. These data support the evidence that foliar application of 2,4-D is an effective option to enhance the color of most red-skin potatoes, while foliar application of Ca is not influential on skin color and may decrease tubers specific gravity in soils with adequate Ca supply