Common green sweet basil, Ocimum basilicum L., is a viable crop for fresh market greenhouse
production due to its high dollar value and increasing demand. Organically and hydroponically grown
products conserve natural resources while providing a marketing edge and sales advantage for producers.
Hydroponic organic growing methods hlfill a need for locally grown organic produce during the offseason.
Data on greenhouse production of fresh market basil is needed by Colorado growers for efficient
and profitable production.
Growinghrigation systems had an effect on the hydroponic greenhouse production of fresh
market basil. Comparison of bag mix, perlite, and rockwool growing systems were made within fertilizer
treatments. Differences were found between growing systems for total harvest per plant, final plant dry
weight, and final plant heights depending on the fertilizer treatment and the summerlfall 1996 or
sprinsjsurnmer 1997 growing season.
Comparisons were also made between fertilizer treatments within growing media. Organic
fertilizer produced an equally, more, or less productive basil crop compared to the conventional, salt-based
fertilizer depending on the growing system, the week of harvest, the Fusarium infection in 1997, and the
growing season. Variables of interest were weekly harvested fresh weights, weekly harvested dry weights,
and weekly SPAD readings with a chlorophyll meter. Nitrate nitrogen measurements and a complete plant
leaf tissue analysis were taken at the termination of each study. Additionally, organoleptic taste test panel
members performed a triangle difference test between the organically fertilized plants and the salt-based
fertilized plants within each of he three growing systems. Panel members also performed a preference test
between fertilized and conventionally fertilized plants.
This research determined that basil can be successfully grown hydroponically and organically in a
Colorado greenhouse. The physical appearance and health of the plants declined after four months of
weekly harvesting in the 1996 and 1997 studies. The 1996 study shows a general downward trend in fresh
weight and dry weight yields for all growing systems reflective of the decreasing light intensities while the
1997 study shows an upward trend in fkesh weight and dry weight yields for all growing systems reflective
of increasing photoperiod reactions