Search Results

You are looking at 51 - 60 of 356 items for :

  • "container production" x
  • All content x
Clear All
Free access

Michael A. Arnold

Quercus shumardii Buckl. seedlings were grown for 3 or 7 months in 2.3-liter black plastic containers. Containers were either treated or not on interior surfaces with 100 g Cu(OH)2/liter latex carrier. Trees were transplanted in summer or fall to quantify post-transplant responses to mechanical correction or chemical prevention of circling roots. Four treatments were used at each transplant date; nonpruned seedlings from Cu(OH)2-treated or nontreated containers, and seedlings from nontreated containers in which two mechanical root pruning techniques were used, traditional severing of circling roots on the rootball periphery or splitting and splaying the bottom two-thirds of the rootball at transplant (butterfly pruning). Traditional root pruning severed more small-diameter roots (≤0.5 mm), while butterfly pruning severed more large-diameter roots. During the first 21 days following transplant most root regeneration was via elongation of intact root tips. Cu(OH)2-treated seedlings regenerated substantially more roots ≤1.0 mm in diameter and a greater root mass than mechanically root pruned or nonpruned seedlings. Both corrective mechanical pruning techniques resulted in greater predawn water stress during immediate post-transplant (21 days) establishment in October than seedlings chemically treated to prevent circling root development. Treatments that severed more roots and/or removed greater root mass were associated with decreased field performance and increased post-transplant water stress. Increased numbers of small- to medium-diameter new roots were associated with reduced post-transplant water stress and improved post-transplant shoot growth. Nonpruned and traditional root pruned seedlings grew little during the first two post-transplant growing seasons regardless of transplant date. Butterfly pruning resulted in severe dieback of shumard oak seedlings. Cu(OH)2-treated seedlings were the only ones to exhibit a gain in height or stem diameter after 2 years in the field.

Full access

R.G. Linderman and E.A. Davis

Formation and function of arbuscular mycorrhizae (AM) are affected by levels of fertility in soil or fertilizers applied to soilless container mixes. For AM fungi, phosphorus (P) is the main element influencing colonization of host plant roots. The question addressed in this study was whether inorganic or organic fertilizers were more compatible with the formation and function of AM. Several controlled-release inorganic (CRI) fertilizers were compared with several organic (OR) fertilizers at different rates (½× to 4× the recommended rate) to determine (1) threshold levels of tolerance by the AM fungus Glomus intraradices in relation to root colonization, and (2) growth responses of `Guardsman' bunching onion (Allium cepa) and `Orange Cupido' miniature rose (Rosa spp.) plants grown in a soilless potting mix or sandy loam soil. AM colonization in soil was greatly decreased or totally inhibited by CRI fertilizers with high P content at the 2× rate or greater, whereas colonization was decreased but never eliminated by low-P OR fertilizers at the 3× rate or greater. Shoot growth of onions was similar with or without AM inoculation when fertilized with CRI, but in general was only enhanced by OR fertilizers if inoculated with AM fungi, compared to the noninoculated controls. Shoot and root growth of onions were significantly increased by AM inoculation when OR fertilizers were used at the 1× rate. In contrast, root growth was not increased by the combination of CRI fertilizers and AM fungal inoculation. Inoculation of miniature roses grown in sandy loam amended with 25% peat and perlite and fertilized with all the CRI or OR fertilizers resulted in high AM colonization, but without much AM-induced growth increase except where OR fertilizers or CRI fertilizers with low P were used. In a soilless potting mix, growth of miniature roses was less with OR fertilizers at the rates used than CRI fertilizers, but mycorrhiza formation was greater in the former unless P was low in the latter. These results indicate that release of nutrients from organic fertilizers, as a result of microbial activity, favors AM establishment and function more than most inorganic fertilizers unless P levels of the latter are low.

Full access

Sven E. Svenson

Shoot and root growth responses of `Cunningham's White' rhododendron (Rhododendron x) was studied when grown in black plastic or molded fiber pots treated with copper hydroxide, or not treated. Containers of two sizes were studied, and the influence of pot type on substrate temperature was recorded. Rhododendron shoot height and dry weight was not influenced by pot volume, pot type, or copper treatment at 49, 131, or 362 d after potting. Rhododendron shoots were larger when grown in 3.8-L (trade 2-gal) pots compared to 2.8-L (trade 1-gal) pots, or when grown in 3.8-L fiber pots compared to 3.8-L plastic pots, both 131 and 362 d after potting. Copper treatment did not influence shoot size. Copper treatment reduced the amount of circling or matted roots at the container-substrate interface for both plastic and fiber pots, but there was better control of root growth in 3.8-L pots compared to 2.8-L pots. Substrate average minimum temperatures were warmer, and average maximum temperatures were cooler when pots were located near the center of the growing block compared to the southwest corner ofthe growing block. Substrate average maximum temperatures were cooler in fiber pots compared to plastic pots, but only when pots were located on the southwest corner of the growing block.

Free access

Thomas J. Brass, Gary J. Keever, D. Joseph Eakes, and Charles H. Gilliam

Growth response of two red maple cultivars (Acer rubrum L. `October Glory' and `Northwood') to styrene lining or copper hydroxide coating of 23.3-liter black plastic containers was evaluated. After the first growing season, plants were left in their original container, repotted into 51.2-liter nontreated containers, or transplanted into the landscape. Copper hydroxide effectively reduced circling of roots of both cultivars at the medium–container interface during the first year of production, but was less effective during the second growing season. Repotting from copper-treated containers into 51.2-liter containers or transplanting into the landscape resulted in more fibrous root development and enhanced root regeneration outside the original rootball relative to transplanting from nontreated containers. However, when copper hydroxide was applied to styrene lining, root regeneration after transplanting was reduced. Roots of plants grown in styrene-lined containers covered the medium–container interface more thoroughly than those in nonlined containers, but height, trunk diameter, and root regeneration were similar. `October Glory' had a larger trunk diameter, more branching, and better root regeneration than `Northwood'.

Full access

Christine E.H. Coker, Gary Bachman, Chris Boyd, Pamela B. Blanchard, Ed Bush, and Mengmeng Gu

The Coastal Roots School Seedling Nursery Program for Habitat Restoration was initiated by Louisiana State University in 2000 in cooperation with Louisiana Sea Grant. The program enhances learning areas such as plant growth, wetland issues, conservation, and hands-on habitat restoration, and includes the installation of a small container nursery for the production of coastal plants in schoolyards. The program was adopted by Mississippi State University's Coastal Research and Extension Center in 2008. The aim of this article is to provide an overview of the program as well as Mississippi's plans to adapt the Louisiana model to demonstrate teaching by example through hands-on demonstration that will supply students with real-world conservation and stewardship experience.

Full access

Chris Wilson, Joseph Albano, Miguel Mozdzen, and Catherine Riiska

Enrichment of surface water with nitrate-nitrogen (NO3-N) is a significant problem throughout the world. In support of developing a method for removing NO3-N from water using denitrification, this project characterized runoff events at two nurseries in southern Florida to provide information needed for designing capacity. Specifically, estimates of runoff rates and volumes, NO3-N concentrations and loadings were profiled during intensively sampled fertigation events at a foliage plant nursery and a bedding plant nursery. Discharge volumes and rates varied with event, ranging from 2,487 to 20,935 L and 59.2 to 126 L·min−1, respectively, per event. NO3-N concentrations ranged from 0.7 to 386.4 mg·L−1, and event loadings ranged from 51 to 3024 g, indicating that significant losses may be realized. This project provided valuable hydraulic and chemical loading information needed for the development and design of bioremediation tools for the horticultural industry.

Free access

Nicholas A. Pershey, Bert M. Cregg, Jeffrey A. Andresen, and R. Thomas Fernandez

The objectives of this study were to quantify irrigation volume, runoff volume and nutrient content, and plant growth of container-grown conifers when irrigated based on plant daily water use (DWU) vs. a standard irrigation rate. Four conifer taxa were grown in 10.2-L (no. 3) containers subjected to four irrigation treatments from 23 June to 16 Oct. 2009 and 6 June to 31 Oct. 2010. The taxa were: 1) Chamaecyparis obtusa Sieb. & Zucc. ‘Filicoides’, 2) Chamaecyparis pisifera (Sieb. & Zucc.) Endl. ‘Sungold’, 3) Thuja occidentalis L. ‘Holmstrup’, and 4) Thuja plicata D. Donn ‘Zebrina’. The four irrigation treatments were: 1) control application of 19 mm·d−1, 2) irrigation applied to replace 100% DWU (100 DWU) per day, 3) applications alternating 100% with 75% DWU in a 2-day cycle (100–75 DWU), and 4) a 3-day application cycle replacing 100% DWU the first day and 75% DWU on the second and third days (100–75–75 DWU). Irrigation treatments did not affect plant growth index {GI= [(H + WNS + WEW)/3]} in 2009. In 2010, GI of C. obtusa ‘Filicoides’ was greater for 100 DWU than the control plants. Seasonal total water applied for 100, 100–75, and 100–75–75 DWU was 22%, 32%, and 56% less, respectively, than the control amount of 117 L per container in 2009 (114 days) and 24%, 18%, and 24% less than the control amount of 165 L per container in 2010 (147 days). Scheduling irrigation based on DWU reduced runoff volumes and (nitrate-nitrogen) NO3 -N and (phosphate-phosphorous) PO4 3−-P load compared with the control. Irrigating based on DWU reduced water application and runoff volumes and NO3 -N and PO4 3−-P load while producing plants of equal or greater size than control plants.

Full access

Yu-Sen Chang and Chen-Yu Lin

The effect of copper hydroxide [Cu(OH)2] applied to interior container surfaces on shoot and root responses was evaluated on palimara alstonia (Alstonia scholaris). The seedlings grown in Cu(OH)2-treated containers had greater plant height than those in untreated containers, and had no observable copper toxicity symptoms. Cu(OH)2-treated containers effectively reduced root circling on the surface of rootballs compared with untreated containers. The Cu(OH)2 treatment significantly increased the dry weight of fine roots (those with a diameter 0-2 mm) and small roots (>2-5 mm) but did not influence the dry weight of medium roots (>5-10 mm), large roots (>10 mm), or total roots. The Cu(OH)2 treatment also significantly increased total root length and surface, which was due principally to the increasing length and surface of the fine roots. The results indicated that the Cu(OH)2 treatment, which can improve the root quality of palimara alstonia seedlings and thereby increase the root-length-to-leaf-area ratio and the root-surface-to-leaf-area ratio, has the potential to produce high-quality plants.

Free access

R.C. Beeson Jr.

Large (≈5 m high) Quercus virginiana Mill. (live oak) trees produced in 0.64-m-diameter in-ground fabric containers were root pruned or not root pruned inside containers before harvest. Harvested trees were grown in two sizes of polyethylene containers for 10 months, then transplanted into a landscape. Water potential (ψT) of small branches (<4 mm in diameter) was measured diurnally during containerization and for 1 year in the landscape. Root pruning had no influence on postharvest survival. Neither root pruning nor container size affected tree water status during containerization or in the landscape. All surviving trees recovered from transplant shock following harvest after 16 weeks in a container, independent of treatment. In the landscape, 35 weeks of daily irrigation were required before dusk ψT declined to within 0.1 MPa of predawn values, a result indicating alleviation of transplant shock. Trunk growth rate during containerization was highest in larger containers. However, in the landscape, root pruning and small containers were associated with higher trunk growth rate. Tree water status during containerization and in the landscape is discussed.

Free access

Michael A. Arnold, Don C. Wilkerson, Bruce J. Lesikar, and Douglas F. Welsh

Studies were conducted using Zea mays L. and Taxodium distichum L. seedlings as model systems to study Cu leaching from Cu(OH)2-treated containers. Initial experiments developed Cu toxicity curves (as CuSO4) in an inorganic (sand) or organic (bark-sand) medium with single (acute) or multiple (chronic) applications. A second pair of experiments investigated short-term (35 days) Cu accumulation and plant responses to irrigation with water (125 mL/plant per day) recycled through a fixed reservoir volume (9.5 L) from 0.7-L Cu(OH)2-treated containers filled with an inorganic or organic medium. Finally, plant responses and Cu leaching were monitored during growth in 2.3-L Cu(OH)2-treated containers filled with two organic media fertigated with high (8.0) or low (6.5) pH solutions. Different Cu(OH)2 concentrations and application methods were tested. Leachate data from the latter studies were used to calculate potential Cu concentrations in nursery runoff using various water application methods and pot spacings. Expression of Cu toxicity symptoms depended on exposure, concentration, and medium for each species. Plants subjected to chronic exposure and grown in an inorganic medium developed toxicity symptoms at lower doses than plants subjected to acute exposure and grown in an organic medium. Several measures of plant growth were greater for both species when grown in 0.7-L Cu(OH)2-treated containers, but not in 2.3-L containers. Plants in Cu(OH)2-treated containers seldom exhibited Cu toxicity symptoms in shoot tissues, even with an inorganic medium. Soluble Cu content of the recycled solution from Spin Out-treated containers increased slightly (<1.2 mg·L-1) during the 35-day experiment. Longer-term studies with nonrecycled leachate from 2.3-L containers indicated that Cu leaching increased after 60 to 90 days. Copper leaching was greater with the combination of applied solution of pH 6.5 and bark-sand-peat medium than with the combination of applied solution of pH 8.0 and bark-sand medium, and increased with greater concentrations of Cu(OH)2 in container wall treatments or when containers were filled before latex carrier was dried. Calculations of potential nursery runoff indicated that the levels of soluble Cu in effluent for most concentrations and spacings projected were below EPA action levels for potable water (1.3 mg·L-1) when overhead irrigation was used.