Survey of Seasonal Variation of Leaf Tissue Nutrient Concentration of Southeastern Blackberry
MSU Affiliation
Extension Service (MSUES); Coastal Research and Extension Center; Mississippi Agricultural and Forestry Experiment Station (MAFES); South Mississippi Branch Experiment Station
Creation Date
2026-06-30
Abstract
The southeastern blackberry (Rubus subgenus Rubus) industry has expanded rapidly in the past two decades. However, fertilizer rate recommendations have been adopted primarily from other regions without verification of their suitability for the cultivars and soils of the southeastern United States. Blackberry leaf tissue nutrient sampling is a practice growers use to monitor plant nutrient status and adjust their fertility programs. Current blackberry leaf tissue nutrient sufficiency ranges used for nutrient monitoring for the region are not based on a regionwide study and have, instead, been adapted from ranges used in other regions. These ranges are developed exclusively for samples collected postharvest, limiting growers’ ability to assess blackberry leaf tissue nutrient status during the growing season. A regionwide survey of the nutrient status of southeastern blackberry was undertaken to verify existing sufficiency ranges and determine whether sufficiency ranges for earlier sampling timings could be developed. In 2022 and 2023, leaf tissue nutrient samples were collected across nine locations in seven southeastern US states (Alabama, Arkansas, Georgia, Mississippi, North Carolina, Tennessee, and Virgina) and analyzed for N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, and B. Not all locations had the same cultivars; but, in total, 12 cultivars were sampled and are representative of the cultivars grown in the region. The most recent mature leaves were collected individually from blackberry primocanes and floricanes at four and five phenological stages, respectively. Phenological stage had a significant effect on all nutrients in primocanes and on all nutrients in floricanes except Mn. Notably, average primocane leaf tissue N, S, Fe, and Mn concentrations from sampling in this study did not fall within currently published leaf tissue nutrient sufficiency ranges for the region. Blackberry primocane leaf N and S concentrations in this study fell within ranges recommended for other regions. Location of sampling (state) and cultivar were found to have some impacts on the leaf tissue nutrient concentration of most nutrients; however, these differences were generally small and no practical differences were observed that would necessitate the development of leaf tissue nutrient ranges specific to subregions or specific cultivars. Instead, phenological stage was the primary influence driving observed seasonal changes in leaf tissue nutrient concentration. Uniform variation in nutrient concentration of primocane leaf tissues across most phenological stages was observed, which indicates there is the potential to develop new sufficiency ranges for phenological stages earlier in the season. Updated sufficiency ranges are recommended for the southeastern blackberry primocane leaf macronutrients N (2.0%–3.0%) and S (0.10%–0.20%) postharvest, whereas the micronutrients Fe and Mn require further investigation.
Publication Date
9-23-2025
Publication Title
HortScience
Publisher
American Society for Horticultural Science
First Page
1928
Last Page
1937
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Lay-Walters, A., Samtani, J., Fernandez, G., Havlin, J., Coneva, E., Stafne, E., Bumgarner, N., Lockwood, D., Rubio Ames, Z., Blaedow, K., & McWhirt, A. (2025). Survey of Seasonal Variation of Leaf Tissue Nutrient Concentration of Southeastern Blackberry. HortScience, 60(11), 1928–1937. https://doi.org/10.21273/HORTSCI18867-25
