Adjusting the percent nitrate in nutrient solution to optimize strawberry stolon and daughter plant production

Authors: Yafuso, Erin; Boldt, Jennifer

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2024
Publication Date: 2/26/2025
Citation: Yafuso, E.J., Boldt, J.K. 2025. Adjusting the percent nitrate in nutrient solution to optimize strawberry stolon and daughter plant production. HortScience. 60(3):435–445. https://doi.org/10.21273/HORTSCI18245-24.
DOI: https://doi.org/10.21273/HORTSCI18245-24

Interpretive Summary: New strawberry plants are propagated from plantlets (called daughter plants) that form on a mother plant. The increase in strawberry fruit production in controlled environments has also increased the demand for year-round availability of healthy daughter plants which growers can use as their starting plant material. This research evaluated nutrient management strategies to increase the number of daughter plants produced by a strawberry mother plants. Providing mother plants with nitrogen in the form of 80% nitrate and 20% ammonium increased daughter plant numbers. This information will help increase the efficiency of controlled environment propagation systems, increase resource use efficiency for growers, and support the increased demand for year-round availability of high-quality strawberry daughter plants.

Technical Abstract: Year-round production of disease-free strawberry (Fragaria × ananassa) daughter plants can be achieved by growing mother plants in controlled environments. However, a lack of protocols exists for nutrient management of mother plants to optimize the production of stolons and daughter plants. Our objective was to identify the optimal percent range of nitrogen (N) supplied as nitrate (%NO3-) in a nutrient solution to maximize strawberry stolon and daughter plant production. Three cultivars (‘Albion’, ‘Fronteras’, and ‘Monterey’) were grown in 20.3-cm pots filled with a peat-based soilless substrate. A strawberry-specific nutrient solution (Yamazaki) provided 100 mg·L-1 N and the N form supplied ranged from 0% to 100% NO3-, with the remainder supplied as ammonium (NH4+). In Expt. 1, ‘Fronteras’ stolon and daughter plant numbers were assessed every 4 weeks for 16 weeks. The harvest interval was too frequent to identify any treatment effects. In Expt. 2, ‘Albion’, ‘Fronteras’, and ‘Monterey’ stolon and daughter plant numbers were assessed at 8 weeks and 16 weeks. Both cumulative stolon number and cumulative daughter plant number exhibited linear or quadratic responses to %NO3-, and the responses were cultivar-dependent. Maximum calculated cumulative stolon number occurred at 64% NO3- for ‘Fronteras’ and at 100% for ‘Albion’ and ‘Monterey’. Maximum calculated cumulative daughter plant number occurred at 66% NO3- for ‘Fronteras’, 81% NO3- for ‘Monterey’, and 100% NO3- for ‘Albion’. Percent NO3- generally did not impact daughter plant quality, such as root number, crown diameter, and dry mass. No trends in foliar %N occurred for either daughter or mother plants across %NO3- treatments; daughter plant %N ranged from 2.38% to 2.63% and mother plant %N ranged from 2.20% to 2.49%. Total aboveground biomass (mother plant + stolons + daughter plants) increased as %NO3- increased from 0% to 100%. ‘Monterey’ had more total aboveground biomass than ‘Albion’ or ‘Fronteras’. Biomass allocation to the mother plant, stolons, and daughter plants differed across cultivars. A calculated range in which all three cultivars overlapped with =95% of maximum daughter plant productivity occurred between 81% to 87% NO3-. A strawberry fertilizer recipe in this target range would allow growers the opportunity to use a single fertilizer recipe and support high daughter plant productivity across multiple cultivars. Our results indicate that optimal strawberry daughter plant production occurs at a lower %NO3- than recommended for inflorescence or fruit production.