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As growers face limited supplies of pine bark--the industry standard for container plant production--alternative substrates are filling in. But woody plants grown in these media must prove their performance in [...]

Wood-based substrates have been extensively evaluated for greenhouse and nursery crop production, yet these substrates have not been evaluated for propagation. The objective of this study was to evaluate processed whole loblolly pine trees (WPT) (Pinus taeda) as a rooting substrate for stem cutting propagation of a range of ornamental crops. Substrates included processed WPT, pine (Pinus sp.) bark (PB), and each mixed with equal parts (by volume) peatmoss (PM) (WPT:PM and PB:PM, respectively). Substrate physical (air space, container capacity, total porosity, bulk density, and particle size distribution) and chemical [pH and electrical conductivity (EC)] properties were determined for all substrates. Rooting percentage, total root length, total root volume, and total shoot length were evaluated for four species in 2008 and five species in 2009. Substrate air space was similar between PB and WPT in the 2008 experiment, and likewise between PB:PM and W-PT:PM. In the 2009 experiment, PB and WPT had similar substrate air space. The addition of PM to PB and WPT resulted in reduced air space and increased container capacity in both experiments. The proportion of fine particles doubled for PB:PM and WPT:PM compared with PB and WPT, respectively. Substrate pH for all substrates ranged from 6.0 to 6.9 at 7 days after sticking (DAS) cuttings and 6.9 to 7.1 at 79 DAS. Substrate EC was below the acceptable range for all substrates except at 7 DAS. Rooting percentage was similar among substrates within each species in both experiments. The addition of PM resulted in significantly greater total root length for PB:PM and WPT:PM compared with PB and W-PT, respectively, for five of the eight species. Shoot growth was most vigorous for PB:PM compared with the other substrates for all species. The study demonstrated a range of plant species can be propagated from stem cuttings in whole pine tree substrates alone or combined with PM. [ABSTRACT FROM AUTHOR]

Residual chipping material, also called clean chip residual (CCR), has potential use as a growth substrate in the nursery and greenhouse horticultural industries. A survey was conducted in the southeastern United States among companies conducting harvesting operations on pine (Pinus sp.) plantations for the production of pulpwood in the forest industry. Fourteen operators in four states (Alabama, Mississippi, Georgia, Florida) were visited to evaluate the on-site status of residual material. Sample analysis of CCR revealed that it was composed of ∼37.7% wood (range, 14.2% to 50.5%), 36.6% bark (range, 16.1% to 68.5%), 8.8% needles (range, 0.1% to 19.2%), and 16.9% indistinguishable (fine) particles (range 7.5% to 31%). pH ranged from 4.3 to 5.5 for all locations and electrical conductivity (EC) averaged 0.24 mmho/cm. Most nutrients were in acceptable ranges for plant growth with the exception of three sites above recommended levels for iron and four sites for manganese. Survey participants estimated that ∼27.5% of the harvest site biomass was composed of CCIL Some harvesters were able to sell CCRas fuelwood to pulp mills, while others did not recover the residual material and left it on the forest floor (44.3% total site biomass). Operations in this survey included typical pine plantation chipping and grinding operations (harvesters), woodyards (lumber, fuelwood, etc.), and operations processing mixed material (salvage from trees damaged in hurricanes or mixed tree species cleared from a site that was not under management as a plantation). Residual material varied depending on the plantation age, species composition, site quality, and natural actions such as fire. Average tree age was 11.5 years (range, 8 to 15 years), while average tree stand height was 37.0 ft (range, 25 to 50 ft) and average diameter at breast height (DBH) was 5.9 inches (range, 4 to 7 inches). Residual material on site was either sold immediately (28.6%), left on site for 1 to 3 months (28.6%), left on site for up to 2 years (7.1%), or not collected/sold (35.7% ). Several loggers were interested in making CCR available to horticultural industries. Adequate resources are available to horticultural industries, rendering the use of CCR in ornamental plant production a viable option. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the potential of milled Paulownia tomentosa (PT) as substrate in greenhouse annual production at the Paterson Greenhouse Complex in Auburn University in Alabama. The study combined PT substrate component with different rates of Canadian sphagnum peatmoss (P) to achieve six treatments for container-grown petunia or dianthus. The study found the influence of PT-amended substrates in the reductions of plant growth.

The article presents a study which aims to assess phytotoxicity in fresh and aged whole pine tree (WPT) substrates. The study conducted two biological assays using the Phytotoxkit and seedling growth test to determine possible phytotoxic effects of wood-based substrates. Results revealed that aged (WPTA) and fresh (WPTF) can be used to propagate plant seeds sensitive to phytotoxic effects.

The article presents a study which aims to determine trace of gas flux from woody ornamentals grown in containers at the Paterson Greenhouse Complex in Auburn, Alabama. The study examined samples from container-grown Ilex vomitoria that were transplanted into four different containers to evaluate efflux of trace gas emissions. Results revealed that carbon dioxide and nitrous oxide were greatest in the largest containers and efflux was higher during late spring and summer months.

The article presents a study which shows the production technique of greenhouse grown annuals through incorporating post-distilled CedarSafe as an alternative substrate. The study implemented six cedar treatments in both petunias and impatiens and collected data using the pour-through method. Results in the study revealed that CedarSafe is a sustainable alternative substrate for petunias and impatiens.

The article discusses a study that examines the effects of media and species on soil CO2 efflux in the landscape. The study transplanted crape myrtle and southern magnolia from liners to determine the effects of growth media in soil CO2 efflux. It also reveals that soil C in the top depth of soil was higher for pine bark (PB) compared to whole tree (WT) and clean chip residual (CCR) for both plant species.

The article discusses a study that examines the annual crop growth in substrates amended with sweetgum, hickory and red cedar. The study evaluated nine treatments including a grower's standard (GS) control consisting of 75 peat to 25 perlite. It also determines the crop's growth indices, flower number, plant dry weight and root growth.

The article discusses a study regarding the use processed corncob as an alternative to perlite in the production of greenhouse grown annuals. The study examines the effects of container grown annuals when grown in a substrate mixed with corncob and compared to the industry standard perlite. It also reveals that substrate containing corncob had greater air space (AS) and total porosity (TP) than those containing perlite.

A conference paper regarding a study on the effectiveness of alternative substrates such as the WholeTree (WT) and Clean Chip Residual (CCR) in woody shrub production is presented. It provides a comparison between the use of traditional pine bark (PB) substrates with that of aged and fresh CCR and WT. It mentions that the alternative substrates have higher wood content compared to pine bark. It adds that the use of CCR and WT could make the plants larger and healthier than the application of PB.

A conference paper regarding an experiment to test the effectiveness of whole pine tree (WPT) substrates in stem cutting propagation is presented. It discusses the use of four substrates to assess root improvement of the Cupressocyparis leylandli Murray and Salvia leucantha subterminal cuttings including whole pine tree:peat moss (WPT:P), pine bark (PB) and whole pine tree (WPT). It adds that the use of WPT promotes the development of total root volume and total root length of the species.

A conference paper on a study that evaluates the growth of Petunia Dream Series in WholeTree (WT) substrate is presented. The study examined the growth of white and Tagetes patula 'Little Hero Yellow' in fresh WT and peat WholeTree (FWP) and aged WT and peat (AWP), as well as the physical properties of the said substrates and substrate components. It says that AWP and FWP had the same total porosity (TP) and bulk density (BD), however, the AWP had higher container capacity (CC) compared to FWP.

A conference paper that further evaluates HydRocks® as a rooting substrate when comparable to four other propagation substrates is presented. Cuttings from woody species are stuck into rooting substrates such as HydRocks® pine bark and sand with rooted cuttings evaluated on root quality, shoot and root growth and rooting percentage. High rooting percentages were observed with similarity for all five species and substrate treatments and that HydRocks may have greater utility.

A conference paper about the assessment of the potential of whole tree (WT), clean chip residual (CCR), and pine bark (PB) with composted poultry litter (CPL) is presented. It explores the adding of CPL as a substrate in producing container-grown nursery crops and the growth of plants having individual differences. The assessment found that high wood substrates are beneficial to future industry needs with or without the CPL.

A study was conducted at Auburn University in Auburn, AL, and the U.S. Department of Agriculture-Agricultural Research Service, Southern Horticultural Laboratory in Poplarville, MS, to evaluate clean chip residual (CCR) as an alternative substrate component for annual bedding plant production. Clean chip residual used in this study was processed through a horizontal grinder with 4-inch screens at the site and was then processed again through a swinging hammer mill to pass a 3/4- or 1/2-inch screen. Two CCR particle sizes were used alone or blended with 10% (9:1) or 20% (4:1) peatmoss (PM) (by volume) and were compared with control treatments, pine bark (PB), and PB blends (10% and 20% PM). Three annual species, 'Blue Hawaii' ageratum (Ageratum houstonianum), 'Vista Purple' salvia (Salvia xsuperba), and 'Coral' or 'White' impatiens (Impatiens walleriana), were transplanted from 36-cell (12.0-inchs) flats into 1-gal containers, placed on elevated benches in a greenhouse, and hand watered as needed. 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, while the largest salvia was in PB:PM and the largest impatiens were in PB-based substrates at Auburn. The GI of ageratum at Poplarville was similar among treatments, but plants grown in 4:1 1/2-inch CCR:PM were the largest. Salvia was largest in 4:1 CCI:PM and PB:PM, and although there were no differences in GI for impatiens at Poplarville, the greatest SDW occurred with PB:PM. Foliar nutrient content analysis indicated elevated levels of manganese and zinc in treatments containing CCR at Auburn and PB at Poplarville. At the study termination, two of three annual species tested at both locations had very similar growth when compared with standard PB substrates. This study demonstrates that CCR is a viable alternative substrate in greenhouse production of ageratum, salvia, and impatiens in large containers. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the potential for use of container substrates composed of processed whole pine trees (WholeTree). Three species [loblolly pine (Pinus taeda), slash pine (Pinus elliottii), and longleaf pine (Pinus palustris)] of 8- to 10-year-old pine trees were harvested at ground level and the entire tree was chipped with a tree chipper. Chips from each tree species were processed with a hammer mill to pass through a 0.374-inch screen. On 29 June 2005 1-gal containers were filled with substrates, placed into full sun under overhead irrigation, and planted with a single liner (63.4 cm³) of 'Little Blanche' annual vinca (Catharanthus roseus). The test was repeated on 27 Aug. 2005 with 'Raspberry Red Cooler' annual vinca. Pine bark substrate had about 50% less air space and 32% greater water holding capacity than the other substrates. At 54 days after potting (DAP), shoot dry weights were 15% greater for plants grown in 100% pine bark substrate compared with plants grown in the three WholeTree substrates. However, there were no differences in plant growth indices for any substrate at 54 DAP. Plant tissue macronutrient content was similar among all substrates. Tissue micronutrient content was similar and within sufficiency ranges with the exception of manganese. Manganese was highest for substrates made from slash pine and loblolly pine. Root growth was similar among all treatments. Results from the second study were similar. Based on these results, WholeTree substrates derived from loblolly pine, slash pine, or longleaf pine have potential as an alternative, sustainable source for producing short-term horticultural crops. [ABSTRACT FROM AUTHOR]

A conference paper on a study which evaluates the growth of woody ornamentals particularly the woody specie of Loropetalum chinensis f. rubrum grown in clean chip residual (CCR) or pine bark (PB) substrates over the course of one year is presented. Data for Loropetalum reveal that plants grown in CCR have similar or greater growth than plants grown in PB. Results demonstrate that CCR can support the growth of woody ornamentals and is a viable option for the nursery industry.

The article discusses a report on the suitability of processed whole pine tree as a substrate component for production of greenhouse crops, presented at the 39th annual conference of the International Plant Propagators' Society's (IPPS) regional chapter in Great Britain and Ireland, which was held in Grobbendonk, Belgium from August 29 to September 1, 2006. A description of the experimental set-up and measurement method is presented.

Hardy ferns are widely grown for use in the landscape. The 1998 National Agricultural Statistics Services census of horticulture reported production of hardy/garden ferns at 3,107,000 containers from over 1200 nurseries. There is little research on herbicide use in hardy ferns, and herbicides that are labeled for container production are not labeled for use on hardy ferns. Studies were conducted to evaluate the tolerance of variegated east indian holly fern (Arachniodes simplicior 'Variegata'), tassel fern (Polystichum polyblepharum), autumn fern (Dryopteris erythrosora), rochford's japanese holly fern (Cyrtomium falcatum 'Rochfordianum'), and southern wood fern (Dryopteris ludoviciana), to applications of selected preemergence applied herbicides. Herbicides evaluated included selected granular or liquid applied preemergence herbicides. Spray-applied herbicides were pendimethalin at 3.0 or 6.0 lb/acre, prodiamine at 1.0 or 2.0 lb/acre, isoxaben at 1.0 or 2.0 lb/acre, and prodiamine + isoxaben at 1.0 + 1.0 lb/acre. Granular-applied herbicides were pendimethalin at 3.0 or 6.0 lb/acre, prodiamine at 1.0 or 2.0 lb/acre, oxadiazon + prodiamine at 1.0 + 0.2 or 2.0 + 0.4 lb/acre, oxyfluorfen + oryzalin at 2.0 + 1.0 or 4.0 + 2.0 lb/acre, trifluralin + isoxaben at 2.0 + 0.5 or 4.0 + 1.0 lb/acre, oxadiazon at 4.0 or 8.0 lb/acre, and oxadiazon + pendimethalin at 2.0 + 1.25 or 4.0 + 2.5 lb/acre. The greatest reduction in growth of autumn fern was observed with the high rates of oxadiazon, oxadiazon + pendimethalin, and oxadiazon + prodiamine. Reductions in rochford's japanese holly fern growth were most severe when plants were treated with the high rate of trifluralin + isoxaben resulting in a 66% and 72% decrease in frond length and frond number, respectively. There were also reductions in frond length and number of fronds when treated with the high rate of oxadiazon + pendimethalin. There were no reductions in frond numbers on tassel fern with any herbicides tested. However, there were reductions in frond length from four of the 10 herbicides evaluated. The most sensitive fern to herbicides evaluated in 2004 was variegated east indian holly fern with reductions in frond length and number of fronds with four of the 10 herbicides tested. Southern wood fern appeared to be quite tolerant of the herbicides tested with the exception of the high rate of oxadiazon. Granular prodiamine proved to be a safe herbicide for all species tested in both 2004 and 2005. In 2005 all plants from all treatments were considered marketable by the end of the study. The durations of both studies were over 120 days giving adequate time for any visual injury to be masked by new growth. However, there was significant visual injury observed on the rochford's japanese holly fern treated with isoxaben at 60 and 90 days after treatment, which might reduce their early marketability. [ABSTRACT FROM AUTHOR]

The article presents a study which evaluates pinebark mini-nuggets for a long-term weed control in nursery crops grown in large containers. Results found out that shredded pine bark mulch has provides good weed control in large containers when applied at a 3-inch depth. This is due to the hydrophobic properties of the fresh pine bark, depth of the mulch, and the lack of favorable growing conditions for weed germination and growth.

Trials were conducted to determine whether propagation environment and/or substrate would encourage adventitious root formation of juvenile sparkleberry (Vaccinium arboreum) cuttings. The first experiment was designed in a 3x2 factorial to test the effects of three substrates (100% perlite, 2:1 perlite/peat, 1:1 perlite/peat) and two different environments ("mist tent" and "sweat tent") on rooting of softwood cuttings The second experiment was designed in a 2x2 factorial to test substrate (Faford® 3B mix and a 2:1 peat/perlite mix) and ± wounding on rooting of hardwood cuttings in two separate environments (mist tent and sweat tent). Due to the low number of cuttings that rooted in all experiments, there were no significant effects of treatments on any of the parameters measured. Previous research indicates that the time of year cuttings are collected is a determining factor for successful vegetative propagation of sparkleberry. [ABSTRACT FROM AUTHOR]

The article presents a study on the offshoot production of groundcover plants in porous ceramic. There are several groundcover plants that are sold as bare-root divisions. When dividing and barefooting these plants, it requires a labor-intensive process. Groundcover plants include Ophiopogon, Hosta, Hemerocallis and Liriope.