Submitted to: Journal of Cotton Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/5/2007
Publication Date: 4/5/2007
Citation: Holt, G.A., Buser, M.D., Harmel, R.D., Potter, K.N., Pelletier, M.G., Duke, S.E. 2007. Weed suppression potential of dry applied mulches used in bedding plant applications: Processed cotton gin byproducts versus conventional wood. Journal of Cotton Science. 11:52-59. Interpretive Summary: Finding a use for cotton gin byproducts that can be implemented across the Cotton Belt has been problematic. One application that shows promise for utilizing processed gin byproducts is the Green Industry (landscape and horticultural markets). In this study, eight cotton-based mulches were evaluated versus conventional wood chip mulch for their effectiveness at suppressing weeds. Six of the cotton-based mulches were cotton gin byproducts. The other two cotton-based mulches were cottonseed hulls and lint cleaner motes. Three of the cotton gin byproduct mulches were processed using USDA’s patented COBY Process. Tests were conducted on 2.31 m2 plots in Manteno, Illinois (Summit Seed, Inc.). The mulches were evaluated at three application rates (1.47, 2.94, and 4.39 kg/m2). The study consisted of taking measurements every week for a total of eight weeks. Each treatment was replicated three times. The results indicate all but one of the cotton-based mulches performed equal to, or better than, the conventional wood mulch at suppressing weeds. The one cotton-based mulch that had significantly more weeds than all other mulches was cotton gin byproducts from one of the three gins were the gin waste was obtained. The plots containing this mulch showed significant increases in the number of weeds as the application rate increased, thus emphasizing the need for weed seed sterilization of raw gin waste. A visual observation of the treatments during the test period revealed that some of the plants in the cotton-based mulch plots did not seem as robust and full flowering as other plots, especially during the first three weeks. Analytical results of the mulches revealed high concentrations of soluble salts in the COBY materials. Some of the soluble salts in the COBY products came from the water and dye used in the process. Refinements of the process to eliminate and/or reduce potential contaminants are being investigated.
Technical Abstract: One of the potential uses of processed cotton gin byproducts (gin waste or gin trash) is mulch in bedding plant applications. A value-added technique, known as the COBY Process, was used to produce three mulches from different types of gin waste (Arizona picker trash, ground Texas stripper trash, and Texas stripper trash). This study investigated the effectiveness of the COBY products compared to the raw material from which they were produced and to a conventional wood mulch at weed suppression. Mulches were applied at 1.47, 2.94, and 4.39 kg/m2. The COBY mulches performed equal to, or better than, the raw gin waste or the wood mulch in suppressing weeds. However, Ageratums planted in two of the COBY treatments exhibited signs of reduced plant growth. The reduced plant growth appeared to be due to high soluble salt concentrations. The increase in soluble salts of the COBY product could be attributed to the water and dye solutions used in the processing. The COBY process can be used to produce a mulch that is effective at suppressing weed growth. The process needs refinement to minimize any negative characteristics or properties for COBY mulch applications where salt sensitive bedding plants are being grown.