Quantifying the effects of fertilizer type, source, and concentration on the post-production growth of containerized culinary herbs

In our first experiment we determined the effect of fertilizer type, source, and concentration on the post-harvest regrowth of containerized culinary herbs. Four different herb species sweet basil (Ocimum basilicum ‘Nufar’), cilantro (Coriandrum sativum ‘Santo’), dill (Anethum graveolens ‘Hera’) and sage (Salvia officinalis) were transplanted into 11.4 cm-diameter containers filled with certified organic substrate and irrigated with solutions containing 100, 200, or 300 mg∙L–1 N from a conventional or organic water-soluble fertilizer (WSF); or were transplanted into the same organic substrate amended with 0.25, 0.5 or 0.75 kg N∙m –3 from conventional controlled-release (CRF) or organic slow-release fertilizer (SRF) and irrigated with clear tap water. Plants were grown in three phases: 1) greenhouse production, 2) simulated retail phase, 3) simulated consumer phase. All fertilizers provided comparable post-harvest regrowth in the consumer phase, regardless of type, source or concentration. In our second experiment, we aimed to determine the effect of the ratios of ammonium to nitrate and phosphorus to nitrogen on containerized herb growth in retail environments. Seedlings of basil ‘Genovese’, cilantro ‘Santo’, dill ‘Fernleaf’ and sage were transplanted into 11.4 cm-diameter containers filled with soilless substrate and irrigated with solutions varying in potential acidity (PA) or potential basicity (PB) and ratios of nitrogen to phosphorous (N:P) from commercially available water-soluble fertilizers . Plants were grown in 2 phases: 1) greenhouse production 2) simulated retail environment. Fertilizers with less P did not restrict plant height during production or retail phases. Substrate pH was greatest for the PB fertilizers for basil and cilantro, while dill and sage had no differences in substrate pH between fertilizers.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

thesis

Discipline thesis:degree_discipline

Horticulture

Department dc:contributor.department

Department of Horticulture

Grantor

Iowa State University

Year dc:date.issued

2025

Author dc:creator

• Arment, Nicole

Advisors dc:contributor.advisor

• Currey, Christopher J.
• Haynes, Cynthia
• Gómez, Celina

Language dc:language.iso

en

DOI

https://doi.org/10.31274/td-20251215-249

OAI identifier oai:identifier

oai:dr.lib.iastate.edu:20.500.12876/erLKRKOv