Extracted sweet corn tassels as a renewable alternative to peat in greenhouse substrates

Authors: Vaughn, Steven; Deppe, Nathan; Palmquist, Debra; Berhow, Mark

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/28/2010
Publication Date: 12/15/2010
Citation: Vaughn, S.F., Deppe, N.A., Palmquist, D.E., Berhow, M.A. 2011. Extracted sweet corn tassels as a renewable alternative to peat in greenhouse substrates. Industrial Crops and Products. 33:514-517.

Interpretive Summary: Soilless substrates are primarily used in the production of containerized greenhouse and nursery crops. Sphagnum peat moss is a primary constituent of these substrates and its harvest from endangered ecosystems has become a worldwide concern. Sweet corn tassels are being explored as a source of valuable plant chemicals for use in the pharmaceutical industry. To obtain these chemicals, we extract tassels with ethanol and in the process generate clean and nearly sterile tassel tissues which we have explored as an alternative to peat. In experiments in which peat moss was replaced with increasing levels of ground tassel (up to 50% v/v), the growth and fruit yields of tomato plants were similar to a standard potting mix containing 50% peat/50% vermiculite. From the results of our experiments it appears that ground, extracted sweet corn tassels can be used as a suitable replacement for peat in greenhouse substrates for tomatoes.

Technical Abstract: Soilless substrates are primarily used in the production of containerized greenhouse and nursery crops. Sphagnum peat moss is a primary constituent of these substrates and its harvest from endangered ecosystems has become a worldwide concern. Ethanol-extracted, coarse-ground corn (Zea mays L. ‘Silver Queen’) tassels were examined as a potential peat replacement for potting substrates. Replacing peat moss with increasing levels of ground tassel (up to 50% v/v) elevated pH and electrical conductance, while having variable effects on substrate physical properties (bulk density, percent solids, air porosity, container capacity, and total porosity). Two identical greenhouse experiments separated by time were conducted using tomato (Solanum lycopersicum L. 'Red Robin') plants grown in 6.0-L pots. In the first experiment, all substrates were similar for total tomato yield per plant and number of fruit per plant, with only the 50% tassel substrate having significantly lower values. There were no differences for plant height or average fruit weight among substrates. No differences were found for any of these variables in the second experiment. This research indicates that extracted ground tassels may be utilized as a suitable replacement for peat in greenhouse substrates for tomatoes.