Abstract
Optimal plant growth is crucial in research experiments as well as in nursery operations. Two major factors that influence plant growth are soil mix and fertilizer. Use of commercial soil mixes would be desirable for smaller operations which often lack facilities for mixing and sterilization. Several commercial potting mixes were compared to the UC (University of California) mix for growing citrus plants in our greenhouses at the Citrus Research and Education Center in Lake Alfred, FL. The UC mix is part of the UC system that uses a peat moss based soil mix and fertigation for nutrient supply. Commercial mixes were compared against the original UC mix using the UC system. A fertilizer formulation was used that was previously adjusted for Ca content in the irrigation water. Plant growth and soil pH were measured, and plants were monitored for nutrient deficiencies. Two mixes were found to be comparable to the UC mix in terms of plant growth and lack of micronutrient deficiency. No commercial mixes were found to give better plant growth or fewer deficiency symptoms than the original UC mix. The choice of mix appeared to affect mostly the soil pH and development of deficiency symptoms.
