Abstract
Nutrient and water management is critical for organic greenhouse production of herbs. The objectives of this study were to 1) evaluate suitability of several commercially available organic fertilizers and potting media for organic production of container herbs; 2) develop fertilization programs, including nutrient sources and fertilization rates; and 3) evaluate irrigation methods for small container production systems (4-inch pots). Six greenhouse trials were conducted to achieve these objectives with basil (Ocimum basilicum L.), dill (Anethum graveolens L.), and coriander (Coriandrum ( sativum L.). Potting media did not significantly influence plant growth, quality, and nutrient leaching. Different fertilizers significantly influenced plant growth and market quality. Fertilizer rates ranging from 0.85 to 1.27 g of N per 1 L of potting medium resulted in the best fresh weight and market quality of herbs. Flooding irrigation resulted in the significantly best visual quality, greatest concentration of K+ in plant sap and highest pH in pot leachate; but used 52% and 51% more water than microjet and mister, respectively. As a result of these trials, a practical production method was developed that can easily be adapted by growers interested in the production of greenhouse organic herbs.
