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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #217741
Title: Clean Chip Residual: A New Substrate Component for Growing Annuals

Author
item BOYER, CHERYL - AUBURN UNIVERSITY
item FAIN, GLENN - AUBURN UNIVERSITY
item GILLIAM, CHARLES - AUBURN UNIVERSITY
item GALLAGHER, THOMAS - AUBURN UNIVERSITY
item Torbert, Henry - Allen
item SIBLEY, JEFF - AUBURN UNIVERSITY

Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2008
Publication Date: 7/1/2008
Citation: Boyer, C.R., Fain, G.B., Gilliam, C.H., Gallagher, T.V., Torbert III, H.A., Sibley, J.L. 2008. Clean Chip Residual: A New Substrate Component for Growing Annuals. HortTechnology. 18:423-432.

Interpretive Summary: A study was conducted at Auburn University in Auburn, Ala. and the USDA-ARS Southern Horticultural Laboratory in Poplarville, Miss. to evaluate Clean Chip Residual (CCR) as an alternative greenhouse substrate component for annual bedding plant production. CCR is a by-product of in-field forest operations, which generate “clean chips” used in paper manufacturing. CCR is composed of the remaining material (wood, needles and bark) and is either sold for fuel or spread back across the harvested area. Processed CCR was used in this study and compared to traditional greenhouse substrate to grow three annual species, ‘Blue Hawaii’ ageratum, ‘Vista Purple’ salvia and impatiens. Similarities among treatments in this study indicate that CCR is a potentially viable substrate option for use as a component/replacement for pine bark or peat moss in greenhouse production.

Technical Abstract: A study was conducted at Auburn University in Auburn, Ala. and the USDA-ARS Southern Horticultural Laboratory in Poplarville, Miss. to evaluate Clean Chip Residual (CCR) as an alternative greenhouse substrate component for annual bedding plant production. CCR is a by-product of in-field forest operations, which generate “clean chips” used in paper manufacturing. CCR is composed of the remaining material (wood, needles and bark) and is either sold for fuel or spread back across the harvested area. CCR used in this study was processed through a horizontal grinder with 4-inch screens at the site and then processed again through a swinging hammer mill to pass a ¾- or ½- inch screen. Two CCR particle sizes were used alone or blended with either 10 (9:1) or 20% (4:1) peat moss (by volume) and compared with control treatments, pine bark (PB) and PB blends (10 and 20% peat moss). Three annual species, ‘Blue Hawaii’ ageratum (Ageratum houstonianum), ‘Vista Purple’ salvia (Salvia x superba) and impatiens (Impatiens walleriana), were transplanted from 36-cell (12.0 inch3) flats into 1-gal. containers, placed on elevated benches in the greenhouse and hand watered as needed. Substrates containing 20% peat had the lowest air space and the highest container capacity. Ageratum plants grown at Auburn had leaf chlorophyll content similar or greater than that of plants grown in PB. There were no differences in salvia, however impatiens plants grown in PB substrates at Auburn had less leaf chlorophyll content than those grown in CCR. There were no differences in ageratum, salvia or impatiens leaf chlorophyll content at Poplarville. There were no differences in growth indices (GI) or shoot dry weight (SDW) of ageratum at Auburn. Ageratum at Poplarville was similar among treatments for GI, however there was a increase in SDW for plants grown in 4:1 ¾-inch CCR:peat. Salvia growth at Auburn tended to be largest in PB:peat combinations, although salvia grown in 100% PB and 100% ½-inch CCR were statistically similar in size. Growth indices for salvia at Poplarville indicated less growth in 100% ¾-inch CCR, though 100% ½-inch and 4:1 ½-inch CCR:peat were similar. The greatest SDW of salvia at Poplarville was obtained in the PB:peat combinations, though 4:1 CCR:peat mixtures were statistically similar. Impatiens GI and SDW at Auburn were greatest in PB-based substrates. There were no differences in growth indices of impatiens at Poplarville, though SDW indicated the greatest growth to be in PB:peat combinations. Foliar nutrient content analysis indicated elevated levels of manganese (Mn) and zinc (Zn) in treatments containing CCR at Auburn. At the study termination all plants were marketable and few differences among treatments were visible.