Pine bark (PB) and peatmoss are the two most common substrate components currently used for horticultural crop production in the southeastern United States. The availability and cost of PB remain unpredictable due to reduced forestry production and its increased use as fuel and landscape mulch (Lu et al., 2006). The cost of peat substrates continues to rise due to transportation costs and growing environmental concerns over the mining of peat bogs in Canada and Europe. Therefore, alternative substrates for container production of horticultural crops are important. The use of agricultural waste and other composted materials as a replacement for PB and peat is not a new concept; however, factors such as transportation costs, consistency and reproducibility of product, disease and insect infestation, and availability of composted materials represent concerns for growers (Gouin, 1989; Jackson et al., 2005).
Alternative substrates grown from wood and wood-based products have been investigated as suitable substrates or substrate components in nursery and greenhouse crop production. European research in this area has resulted in numerous successful commercialized wood substrates (Gerber et al., 1999; Grantzau, 1991; Gruda and Schnitzler, 2003; Muro et al., 2005; Penningsfeld, 1992). In addition, Prasad and Fietje (1989) and Worrall (1981) reported successful growth of foliage plants grown in substrates containing wood when compared with plants grown in peat and PB substrates. Annual and herbaceous plants including geranium (Pelargonium ×hortorum), petunia (Petunia grandiflora), impatiens, carnation (Dianthus caryophyllus), and chrysanthemum (Dendranthema ×grandiflorum) have been grown in wood-based substrates (Bragg et al., 1993; Hicklenton, 1983; Starck and Lukaszuk, 1991). More recently, a pine tree substrate has been developed (WoodGro™; WoodGro, Blacksburg, VA) from ground whole loblolly pine logs to successfully produce a wide range of nursery and greenhouse crops (Jackson et al., 2008; Wright and Browder, 2005; Wright et al., 2006, 2008). Pine tree substrate (PTS) derived from entire ground trees (bark, wood, branches, and needles) has also been evaluated as a container substrate or substrate component to produce vinca (Fain et al., 2008).
Understanding the survival and landscape performance of plants grown in PTS is important before PTS can be used for landscape bedding plant production. Previous research describing the post-transplant survival and performance of annual plants grown in a wood-based substrate has not, to our knowledge, been reported. It is well established that wood particles incorporated into the soil (Bollen and Lu, 1957; Lunt and Clark, 1959) or as part of a container substrate (Gruda and Schnitzler, 1999; Jackson et al., 2008; Maas and Adamson, 1972; Wright et al., 2008) may cause N immobilization and require extra N applications for growth comparable to a fully composted organic material such as PB or peatmoss. The N deficiency caused by the incorporation of wood into soil could present a problem regarding planting PTS-grown plants into the landscape. However, this deficiency can likely be overcome with appropriate fertilizer applications. Therefore, the objective of this study was to evaluate the landscape performance of annual bedding plants grown in PTS or PB when transplanted into the landscape and grown at different fertilized rates.
Bollen, W.B. & Lu, K.C. 1957 Effect of douglas-fir sawdust mulches and incorporations on soil microbial activities and plant growth Soil Sci. Soc. Proc. 21 35 41
Bragg, N.C., Walker, J.A.R. & Stentiford, E. 1993 The use of composted refuse and sewage as substrate additives for container grown plants Acta Hort. 342 155 165
Fain, G.B., Gilliam, C.H., Sibley, J.L. & Boyer, C.R. 2008 Whole-tree substrates derived from three species of pine in production of annual vinca HortTechnology 18 13 17
Gerber, T., Steinbacher, F. & Hauser, B. 1999 Holzfasersubstrat zur Kultur von Pelargonium-Zonale-Hybriden biophysikalische und pflanzenbauliche Untersuchung J. Appl. Bot. 73 217 221
Gruda, N. & Schnitzler, W.H. 1999 Influence of wood fiber substrates and nitrogen application rates on the growth of tomato transplants Adv. Hort. Sci. 13 20 24
Gruda, N. & Schnitzler, W.H. 2003 Suitability of wood fiber substrate for production of vegetable transplants I. Physical properties of wood fiber substrates Scientia Hort. 100 309 322
Hicklenton, P.R. 1983 Flowering, vegetative growth and mineral nutrition of pot chrysanthemums in sawdust and peat-lite media Scientia Hort. 21 189 197
Jackson, B.E., Wright, A.N., Cole, D.M. & Sibley, J.L. 2005 Cotton gin compost as a substrate component in container production of nursery crops J. Environ. Hort. 23 118 122
Jackson, B.E., Wright, R.D., Browder, J.F., Harris, J.R. & Niemiera, A.X. 2008 Effect of fertilizer rate on growth of azalea and holly in pine bark and pine tree substrates HortScience 43 1561 1568
Lu, W., Sibley, J.L., Gilliam, C.H., Bannon, J.S. & Zhang, Y. 2006 Estimation of U.S. bark generation and implications for horticultural industries J. Environ. Hort. 24 29 34
Maas, E.F. & Adamson, R.M. 1972 Resistance of sawdusts, peats, and bark to decomposition in the presence of soil and nutrient solution Soil Sci. Soc. Amer. Proc. 36 769 772
Muro, J., Irigoyen, I., Samitier, P., Mazuela, P., Salas, M.C. & Soler, J. 2005 Wood fiber growing medium in hydroponic crop Acta Hort. 697 179 185
Starck, J.R. & Lukaszuk, K. 1991 Effect of fertilizer nitrogen and potassium upon yield and quality of carnations grown in peat and sawdust Acta Hort. 294 289 296
Worrall, R.J. 1981 Comparison of composted hardwood and peat-based media for the production of seedlings, foliage, and flowering plants Scientia Hort. 15 311 319
Wright, R.D., Jackson, B.E., Browder, J.F. & Latimer, J.G. 2008 Growth of chrysanthemum in a pine tree substrate requires additional fertilizer HortTechnology 18 111 115
Wright, R.D., Browder, J.F. & Jackson, B.E. 2006 Ground pine chips as a substrate for container-grown wood nursery crops J. Environ. Hort. 24 181 184