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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #229852

Title: Production of Woody Nursery Crops in Clean Chip Residual Substrate

item Torbert, Henry - Allen

Submitted to: Journal of Environmental Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2008
Publication Date: 1/1/2009
Citation: Boyer, C.R., Gilliam, C.H., Fain, G.B., Gallagher, T.V., Torbert III, H.A. 2009. Production of Woody Nursery Crops in Clean Chip Residual Substrate. Journal of Environmental Horticulture. 27:56-62.

Interpretive Summary: As the expense of growing nursery crops continues to rise along with labor shortages and higher material prices, it has become increasingly important to search for production practices that will lower input costs for growers. With recent and continued trends in the reduced availability of pine bark (PB) a promising avenue for reducing production costs has been the development of alternative substrates. Clean chip residual (CCR) is a forest residual material, a by-product of in-field harvesting of small-diameter pine trees for ‘clean chips’ used in paper manufacturing. Utilizing CCR as a nursery crop substrate could potentially lower costs to growers and provide a sustainable, local/regional substrate resource in the Southeast U.S. Our data shows that plants grown in CCR had comparable growth to plants grown in PB.

Technical Abstract: Clean chip residual (CCR) is a potential replacement for pine bark (PB) in nursery crop substrates. It is a by-product of in-field forestry harvesting practices and has been shown to produce annual plants and perennials similar in size to plants grown in PB. Studies were conducted in two locations, Auburn, AL and Poplarville, MS to evaluate growth of woody ornamentals grown in CCR or PB. Five species were tested; Loropetalum chinensis var. rubrum, Buddleia davidii ‘Black Knight’, Lagerstroemia indica ‘Hopi’, Lagerstroemia x fauriei ‘Natchez’, and Rhododendron indicum ‘Mrs. G.G. Gerbing’. There were few differences in plant growth indices, leaf chlorophyll content, and inflorescence number over the course of the year for all species at both sites. Percent rootball coverage was generally similar among treatments, though those grown in PB had the greatest percent rootball coverage for loropetalum and buddleia (at both sites) and azalea at Auburn. Shoot dry weight of loropetalum and crapemytrle grown in PB at Poplarville was greater than plants grown in CCR. Data indicates that plants grown in CCR had comparable growth to plants grown in PB.