bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pruning Lower Branches of Live Oak (Quercus virginiana Mill.) Cultivars and Seedlings during Nursery Production: Balancing Growth and Efficiency
Authors: Gilman Edward F. , Anderson Patti J. , Harchick Christopher 
Published: August 2020

Abstract
Tree production requires time for pruning to meet customer expectations, yet pruning can slow growth and increase the time (and cost) to prepare trees for market. Our research quantifies trade-offs between growth and pruning. In two separate locations, over two time periods, we found no difference in caliper growth between trees with only the largest one or two low branches removed at each pruning, compared with trees having all lower branches shortened. Acorn-propagated and Cathedral Oak® Quercus virginiana (Mill.) with all branches removed from the lower 1.37 m (4.5 ft) of trunk (temporary branches destined to be removed to produce a trunk clear of branches and a distinct canopy) by 18 months after planting had smaller caliper than other pruning treatments; however, pruning these branches had no impact on the Highrise® cultivar. Removing the largest one or two low branches at each pruning was the most efficient pruning method tested. Removing all temporary branches in February of the last year of production (2004) did not reduce caliper, height, or canopy spread compared to removing half in February and half in October. Since there was no difference in time required for pruning, we suggest removing branches early in the last growing season for more completely closed wounds and enhanced customer appeal.
Nursery Production of Helleborus x hybridus: Management of Nitrogen and Substrate pH
Authors: Kraus Helen T. , Warren Stuart L. 
Published: August 2020

Abstract
One-year-old seedlings of Helleborus x hybridus Hort. Ex Vilmorin (Lenten rose) were potted into 3.8 liter (#1) containers filled with a pine bark substrate amended with one of five rates of dolomitic limestone [0, 1.4, 2.7, 4.1, or 5.4 kg/m3 (0, 3, 6, 9, or 12 lb/yd3)]. Substrate pH responded quadratically with increasing rate of dolomitic limestone (DL) producing a range of substrate pH from 4.5 to 6.9. Nitrogen application rates (NARs) ranging from 10, 20, 40, 80, and 160 mg/liter were applied with every irrigation. Top dry weight was affected by NAR, DL, and NAR × DL rate interaction. When no DL was added to the substrate, top dry weight increased quadratically with increasing NARs with maximum dry weight occurring with N at 124 mg/liter. However, when the substrate was amended with DL at 1.4, 2.7, 4.1, or 5.4 kg/m3 (3, 6, 9, and 12 lb/yd3) top dry weight increased linearly with increasing NARs with maximum top dry weight of 15 g to 16 g (0.53 oz and 0.56 oz) occurring with N at 160 mg/liter. Contrast analysis comparing DL rates within each NAR revealed DL rates of 1.4, 2.7, 4.1, and 5.4 kg/m3 (3, 6, 9, and 12 lb/yd3) produced greater top growth compared to growth at the DL rate of 0 kg/m3 (0 lb/yd3) at NARs of 40, 80, and 160 mg/liter. Furthermore, when fertilized with N at 40, 80 or 160 mg/liter, top dry weight produced with DL rates of 1.4, 2.7, 4.1, and 5.4 kg/m3 (3, 6, 9, and 12 lb/yd3) did not differ within each NAR. Root dry weight was unaffected by NARs and NAR × DL rate interaction. Rate of DL affected root dry weight with the largest increase in root growth occurring with DL between 0 kg/m3 and 1.4 kg/m3 (0 lb/yd3 and 3 lb/yd3). Root-to-top ratio (RTR) responded quadratically with increasing NAR with the lowest RTR occurring with N at 140 mg/liter. Foliar N, P, K, Ca, Mg, S, and Fe concentrations were unaffected by rate of DL and NAR × DL rate, whereas foliar N, P, K, Ca, Mg, and S were affected by NARs. Foliar N, P, K, and S concentrations responded quadratically to increasing NARs; foliar Ca and Mg concentrations were linear; and foliar Fe concentration was unaffected by NARs.
Establishment and Growth of Begonias in the Landscape as Affected by Root Ball Condition at Transplanting
Authors: Scheiber S.M. , Beeson Richard C. 
Published: August 2020

Abstract
Begonias (Begonia semperflorens) were transplanted into an open-sided clear polyethylene covered shelter to evaluate the effect of root ball condition on establishment and growth. Three root ball classes were evaluated: non root-bound (NRB; 6 week old plants), root-bound (RB; 10 week old plants), and root-bound with the bottom 1 cm of the root ball removed (RBM). Non root-bound plants had greater growth rates for both height and faster rates of accumulation for cumulative root dry mass and new root dry mass relative to the other treatments tested. Cumulative shoot dry mass, new shoot dry mass, and total biomass accumulation rates were slower among RB plants compared to other rootball conditions. Mean canopy size, shoot dry mass, and biomass of NRB were significantly less at transplant; however all parameters were comparable among treatments 12 weeks later. Final mean shoot to root ratios were lower for the NRB treatment relative to RBM. Results indicate smaller, NRB transplants establish faster in the landscape. Furthermore, rootball manipulation is not recommended as it had no significant effect on root establishment or canopy growth of this annual bedding plant in the landscape.
Postemergence Liverwort Control in Container-Grown Nursery Crops
Authors: Newby Adam , Altland James E. , Gilliam Charles H. , Wehtje Glenn 
Published: August 2020

Abstract
Four experiments were conducted in Aurora, OR, and Auburn, AL, to evaluate effectiveness of herbicides for postemergence liverwort control. A sprayable herbicide, quinoclamine (Gentry 25-WP), was applied at rates between 1.8 and 7.6 kg ai/ha (1.6 and 6.8 lb ai/A), with or without a surfactant, and in spray volumes of 1019 or 2037 liters/ha (109 or 218 gal/A). Across all experiments, postemergence liverwort control was good (&gt;90%) at the lowest rate when liverwort infestation was light (liverwort covered ≤25% of the substrate surface with no sporocarps). When liverwort infestation was high (liverwort covered ≥60% of the substrate surface with some sporocarps present), or in conditions favorable to liverwort growth, control improved by using higher rates or including a surfactant. At the highest labeled rate (7.6 kg ai/ha (6.8 lb ai/A)), postemergence liverwort control up to 14 days after applications was 96 to 100% across all four experiments. Long-term liverwort control through 42 to 56 days after application varied depending on the location and time year, with control decreasing as environmental conditions allowed for increased liverwort vigor. Sodium carbonate peroxyhydrate (TerraCyte) provided poor to moderate control, and was largely dependent on liverwort vigor. Flumioxazin (BroadStar) provided unacceptable postemergence control across all experiments.
Seasonal Biomass and Nitrogen Accumulation of Rosa ‘Mariandel®’ Grown in Compost Amended Peat at Different Fertilization Rates
Authors: Amha Yosef , Bohne Heike 
Published: August 2020

Abstract
The growth and nitrogen (N) uptake of Rosa ‘Mariandel®’ were evaluated at four fertilization rates: 0, 0.4, 0.8 and 1.2 g N/liter (0, 0.016, 0.032 and 0.048 oz/qt). Plants were harvested at 6-week intervals. New shoots in all treatments retained the highest relative dry weight percentage, apparently at the expense of root. The total N concentration, content, and uptake at 12 and 18 weeks, but not at 6 weeks, after potting were significantly (r2 &gt; 0.59; P = 0.0005) affected by rates of fertilization. Although DM in the old shoots of all treatments slightly increased over the first 6 weeks, the corresponding N content decreased due to translocation. Except in old shoots, a significant linear trend occurred between DM accumulation and N content but not with N concentration (at least up to 12 weeks). However, N concentration in most plant parts was significantly (P &lt; 0.05) correlated with the respective N content. Excluding N released from the substrate, plants in 0.4, 0.8 and 1.2 g N/liter treated pots received 80, 126 and 182 mg (0.003, 0.004 and 0.006 oz) N per week, respectively, as used Osmocote (15N–4P–7.5K–1.8Mg) showed a linear (r2 &gt; 0.99) N-releasing rate. The corresponding total mineralized N in each control pot was 96 mg (0.003 oz) and 140 mg (0.005 oz) over the first and the second 6-week interval. Overall, ‘Mariandel®’ grown in 0.8 and 1.2 g N/liter treated pots had the highest mean N concentration and content respectively.
Plant Growth Retardants Affect Growth and Flowering of Achillea × ‘Coronation Gold’
Authors: Kessler J.R. , Keever G.J. 
Published: August 2020

Abstract
An experiment was conducted to determine the effects of several widely used plant growth retardants on plant size and flowering of Achillea × ‘Coronation Gold’. Plants in 10 cm (4 in) pots were grown in a greenhouse and treated with B-Nine at 0, 2550, 5100, or 7650 ppm; Cycocel at 0, 767, 1534, or 2301 ppm; B-Nine/Cycocel at 0, 1275/1534, 2550/1534, or 3825/1534 ppm; Sumagic at 0, 11, 22, 33, 44, or 55 ppm; Bonzi at 0, 32, 64, 96, 128, or 160 ppm; or Cutless at 0, 40, 80, or 120 ppm as a spray 1 week after vernalization. B-Nine, Cycocel, B-Nine/Cycocel, Sumagic, Bonzi, and Cutless reduced shoot height and growth index by 36 and 26%, 39 and 27%, 61 and 41%, 75 and 52%, 52 and 36%, and 75 and 51%, respectively, with the highest rate of each. B-Nine, Cycocel, B-Nine/Cycocel, and Sumagic, but not Bonzi or Cutless, increased the number of days to open inflorescence by 3-5 days with increasing rate. Sumagic, Bonzi, and Cutless reduced inflorescence diameter by up to 15, 18, and 14%, respectively but not B-Nine, Cycocel, or B-Nine/Cycocel. The highest quality ratings of 2.8 to 3.0 were found with B-Nine/Cycocel at 3825/1534 ppm, Sumagic at 22 and 33 ppm, and Bonzi at 64 ppm. Differences between the results in this study and earlier studies implicate the possible impact of differences in experimental environments, container size, or stage of development when the plant growth retardant treatments were applied.
Weed Control and Phytotoxicity Following Preemergence Herbicide Applications to Container-grown Herbaceous Plants
Authors: Klett James E. , Staats David , Howlett Teri , Rogoyski Matthew 
Published: August 2020

Abstract
Effectiveness of five preemergence herbicides was determined for four container-grown ornamental crops. Herbicides tested were Barricade (prodiamine); BroadStar (flumioxazin); Gallery (isoxaben); Scotts Ornamental Weedgrass Control (Scotts OWC) (pendimethalin); and Treflan (trifluralin). Four herbaceous plant species were utilized in this trial, namely, Guizhou sage (Artemisia lactiflora Wall. (Guizhou group)); hopflower oregano (Origanum libanoticum Boiss.); Daghestan sage (Salvia daghestanica Sosn.); and skullcap (Scutellaria resinosa Torr.). The seven weed species evaluated in this trial were annual bluegrass (Poa annua L.); barnyardgrass (Echinochloa crus-galli L.); yellow foxtail grass (Setaria glauca L.); purslane (Portulaca oleracea L.); common groundsel (Senecio vulgaris L.); redroot pigweed (Amaranthus retroflexus L.); and annual sowthistle (Sonchus oleraceus L.). Two controls, one with weeds and one without were also evaluated. The experiment was conducted in two locations: Fort Collins and Grand Junction, Colorado. Weed control levels varied across a range of herbicide treatments and ornamental species. Where differences among herbicides were observed, BroadStar and Treflan tended to be more effective than the other herbicides, while Gallery, Scotts OWC and Barricade, were less effective. Plants treated with Gallery often resulted in decreased dry weights; however, no visual phytotoxicity symptoms were observed with any herbicide treatments. Daghestan sage and skullcap were the crop species most adversely effected.
Growing Blackgum Whips in Ground Beds Increases Survival and Growth Following Transplanting to Field
Authors: Struve Daniel K. 
Published: August 2020

Abstract
Difficult-to-transplant species can be produced in containers and transplanted with high survival. However, circling roots can develop even in containers designed to prevent root malformation, requiring root pruning before transplanting and this results in transplant shock. In order to determine the effect of different containers and substrates on whip growth and survival after transplanting, blackgum (Nyssa sylvatica Marsh.) whips were grown in four container types (Spinout®-treated plastic, tall or short fiber containers or in ground beds) and two substrates (pine bark: Com-Til™ and Haydite: Com-Til™). Container-grown whips were overwintered in unheated polyhouses; bed-grown were overwintered out-of-doors with no winter protection. Two year branched whips grown in Haydite: Com-Til™ were bare rooted and root pruned before transplanting. Whips grown in containers required root pruning to correct root malformation, while whips grown in pine bark: Com-Til™ in ground beds were root pruned as part of the harvesting process. Container and substrate treatment did not affect whip stem diameter, but whips grown in ground beds in pine bark: Com-Til™ were the tallest. Overwinter survival for container-grown whips ranged from 77 to 88% and averaged 85% for whips grown in ground beds. The percentage of whips reaching 1.2 m in height ranged from 53 to 97% for whips produced in tall fiber containers in Haydite: Com-Til™ substrate and in short fiber containers in Haydite: Com-Til™ substrate, respectively. Two years after whips were transplanted, survival averaged 98% (174 of 178). Two years after transplanting, whips produced in beds in pine bark: Com-Til™ substrate had the greatest caliper. Whips produced in ground beds in pine bark: Com-Til™ offer an acceptable alternative to container-produced blackgum whips; they had high overwintering and transplant survival; they were taller at the end of the two year whip production period, and two years after transplanting to field plots they had the largest trunk caliper.
Growth of Moonshine Yarrow on a Limited Moisture Budget
Authors: Khalil Shad Khan , St. Hilaire Rolston , O’ Connell Mary , Mexal John 
Published: August 2020

Abstract
Yarrow is an herbaceous perennial that is highly recommended for landscape gardens in many parts of the United States. However, performance data of yarrow produced under limited irrigation conditions is lacking. During 2004 and 2005, we studied the growth and physiology of yarrow (Achillea ‘Moonshine’) maintained as well irrigated controls or irrigated when there was a 30 or 60% depletion of moisture in the growing substrate. Plants irrigated at the 60% moisture level had the lowest predawn water potential, stomatal conductance and transpiration rate. Cell osmotic potential and relative water content data suggest that yarrow might be able to withstand prolonged exposure to drought. In 2005, net assimilation rate of well irrigated plants (0.317 mg/cm2/d) was almost twice as high (0.179 mg/cm2/d) as that of plants maintained at the 60% moisture level. This suggests that a 60% moisture depletion level had a very significant impact on carbon assimilation. In 2005, leaf area of plants irrigated at the 30% moisture depletion level showed only a 15% decline compared to well irrigated plants, while those irrigated at the 60% moisture depletion level showed a 47% decline in leaf area.
Planting Depth in Containers Affects Root Form and Tree Quality
Authors: Gilman Edward F. , Harchick Chris 
Published: August 2020

Abstract
After 40 months in air root pruning containers, Quercus virginiana ‘SDLN’ Cathedral Oak® live oak planted 3.8 and 8.9 cm (1.5 and 3.5 in) deep from rooted cuttings had greater caliper than trees planted at 1.3 cm (0.5 in) below substrate surface. Trees in the 1.3 cm (0.5 in) deep treatment grew taller than all other trees except for those in the 3.8 cm (1.5 in) deep treatment. Most (80%) trees were graded as culls according to root evaluations in the Florida Grades and Standards for Nursery Stock. This resulted mostly from roots circling and crossing the top of the root ball in the #3 and/or #15 container sizes. Trees planted 6.4 cm (2.5 in) deep in #3s, then 6.4 cm deep in #15s, and 6.4 cm deep in #45s [19 cm (7.5 in) total depth] had fewer, smaller diameter, and deeper primary roots than trees planted at all other depths. The presence of a trunk flare and surface roots decreased with increasing planting depth indicating that these could be used as an indicator of primary root depth. Cathedral Oak® demonstrated the capacity to generate new roots above the primary flare roots only when rooted cuttings were planted into #3 containers. Trees adjusted their root systems by generating a new set of roots along the buried stem up to the substrate surface. Roots did not grow from the buried portion of the stem when trees in #3 containers were planted 6.4 cm (2.5 in) deep into #15 containers. In other words 75% or more of the primary structural roots were deflected by either the #3 or #15 container wall or both, indicating that most primary roots that emerged from the trunk did so when the tree was in the #3 or #15 container within 22 months of planting from rooted cuttings. Roots often grafted when crossed or laid against other roots, but roots did not graft to trunks.
Flowering, Fecundity, Seed Germination, and Seed Viability of Viburnum opulus L. Cultivars
Authors: Conklin Janine R. , Sellmer James C. 
Published: August 2020

Abstract
Mature specimens of Viburnum opulus and cultivars ‘Leonard's Dwarf’ and ‘Roseum’ were assessed over 2 years for flower and seed production, seed germination, and seed viability as determined by a tetrazolium test to understand their invasive potential. ‘Aureum’, ‘Compactum’, ‘Losely's Compact’, ‘Nanum’, and ‘Xanthocarpum’ were also tested for germination and viability of seeds. Cultivars differed in flower and seed production, seed germination, and seed viability. ‘Roseum’ prolifically produced highly viable seed that germinated at moderate rates under greenhouse conditions (8,354, 100%, and 73%, respectively). Viburnum opulus and ‘Leonard's Dwarf’ produced fewer viable seed which showed moderate to low germination rates (609, 100%, and 53%; 712, 100%, and 5%, respectively). ‘Aureum’ and ‘Xanthocarpum’ seeds germinated at moderate rates (55 and 25%, respectively) and were highly viable (100%). ‘Compactum’, ‘Losely's Compact’, and ‘Nanum’ germinated at low rates or failed to germinate (0, 0, and 5%, respectively), yet seeds were moderately viable (37, 65, and 55%, respectively). Seeds of all cultivars germinated at low rates or failed to germinate at both outdoor sites (0 to 5%) which suggests these plants may be weakly invasive. Short-term studies on biological traits such as these provide only limited information to assess the invasive potential of cultivars.
Performance of Mycorrhizal Products Marketed for Woody Landscape Plants
Authors: Eric Wiseman P. , Colvin Kristen H. , Wells Christina E. 
Published: August 2020

Abstract
Commercial products containing propagules of arbuscular mycorrhizal fungi (AMF) are widely marketed to improve woody plant performance in the landscape. However, the infectivity of these products has rarely been subjected to independent testing. We evaluated commercial AMF inoculants in a series of greenhouse experiments using corn (Zea mays), sorghum (Sorghum bicolor), trident maple (Acer buergerianum), and sweetbay magnolia (Magnolia virginiana) as host plants. In corn and sorghum, colonization rarely exceeded 5% when plants were treated with commercial inoculants. In contrast, viable lab-cultured inoculant of similar species composition yielded mean colonization percentages of 38 to 61%. Despite the near absence of colonization, commercial inoculants generally improved shoot growth and increased soil nutrient concentrations in a dose-dependent manner. Commercial inoculants had no effect on mycorrhizal colonization or shoot growth of trident maple or sweetbay magnolia liners. Product-treated magnolias grown from seed also developed little or no mycorrhizal colonization, whereas plants treated with a lab-cultured inoculant were 74% colonized. If commercial AMF inoculants are to receive broad acceptance as landscape soil amendments, manufacturers must demonstrate that their products can promote mycorrhizal colonization under the conditions of their intended distribution and use.
Preemergence Control of Black Cottonwood in Nursery Containers
Authors: Altland James E. 
Published: August 2020

Abstract
Two experiments were conducted to evaluate preemergence herbicides for control of black cottonwood (Populus trichocarpa) in nursery containers. In 2006, granular preemergence herbicides were applied to recently filled, weed-free containers in May just prior to seed release from mature cottonwood trees. Flumioxazin provided the most effective cottonwood control, although control with isoxaben + trifluralin, oxyfluorfen + oryzalin, and pendimethalin was also effective. In 2007, containers were filled February 15, and herbicides were applied to separate groups of containers on February 22, March 14, April 16, and May 15. Containers were over-seeded with cottonwood for a 2-week period starting on May 16. Control with most herbicides improved as the date of application neared the date of seeding. Flumioxazin provided the most effective control throughout the experiment, but control from it also improved as the date of application neared the time of seeding.
Bare Root Liner Production Can Alter Tree Root Architecture
Authors: Hewitt Angela , Watson Gary 
Published: August 2020

Abstract
Typical nursery production practices, such as root pruning and transplanting, can alter tree root architecture and contribute to root systems that are too deep. In a study of field-grown liner production, root architecture was examined at each stage of the production process, from first year seedlings or rooted cuttings, through 4 to 5 year old branched liners. Depth and diameter of structural roots were recorded on ten replications each of Acer saccharum, Gleditsia triancanthos, Pyrus calleryana, and apple seedling rootstocks; Platanus ‘Columbia’ clonal rooted cuttings; and apple EMLA 111 clonal rootstock produced by mound propagation. By the time the liners reached marketable size, most natural lateral roots emerging from the primary root were lost. Simultaneously, adventitious roots were produced deeper on the root shank at the pruned end of the primary root. These changes in architecture result in the formation of an ‘adventitious root flare’ that is deeper in the soil than a natural root flare. The depth of this new root flare is dependent upon nursery production practices and may influence the ultimate depth of structural roots in the landscape.