bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regeneration of Mugwort (Artemisia vulgaris) from Rhizome Sections in Sand, Pine Bark, and Soil Substrates
Authors: Klingeman William E. , Robinson Darren K. , McDaniel Gary L. 
Published: August 2020

Abstract
Regenerative potential of mugwort (Artemisia vulgaris L.) rhizome sections has not been quantified when rhizomes are transplanted into substrates encountered in landscapes and nursery fields, container nurseries, or propagation beds. Mugwort regeneration in pine bark, sand, and soil substrates was analyzed by rhizome color, length, and the presence or absence of a leaf scale. Color of rhizomes, which darken with time, did not account for differences in growth among treatments. Contrary to previous research, 85, 78, and 69% of 2 cm-long rhizome sections produced both roots and shoots when grown in pine bark, sand, and soil substrates, respectively, during 45-day trials. Slightly less than 31% of rhizome fragments 0.5 cm long without a leaf scale produced both roots and shoots in soil. Though fewer rhizomes survived in soil, root and shoot fresh weights were greater than in pine bark and sand. When rhizome sections included a leaf scale, survival, fresh weights of roots and shoots, shoot height, leaf number and root lengths were greater, regardless of substrate type. Root initials emerged both adjacent to leaf scales and in the internode between leaf scales. Shoot emergence preceded root emergence from rhizome sections.
Evaluation of 19 American Elm Clones for Tolerance to Dutch Elm Disease
Authors: Townsend A. M. , Bentz S. E. , Douglass L. W. 
Published: August 2020

Abstract
Rooted stem cuttings of 19 American elm (Ulmus americana L.) cultivars and selections, and rooted cuttings of two non-American elm selections, U. carpinifolia Gleditsch 51 and 970 (U. glabra Huds. x (U. wallichiana Planch. x U. carpinifolia)), along with a group of American elm seedlings, were planted in a randomized block design. When the trees were nine years old, they were inoculated with a mixed spore suspension of Ophiostoma ulmi (Buisman) C. Nannf. and Ophiostoma novo-ulmi Brasier, the causal fungi for Dutch elm disease (DED). Analyses of variance showed highly significant variation among clones in foliar symptoms 4 weeks after inoculation and in crown dieback one and two years after inoculation. After two years, 13 of the American clones showed significantly less dieback than the American elm seedlings, and 18 American clones showed significantly less injury than a randomly chosen, unselected American elm clone, 57845. The American clones with the most DED-tolerance were cultivars ‘Valley Forge,’ ‘Princeton,’ ‘Delaware,’ and ‘New Harmony,’ and selections N3487, R18-2, 290, 190, and GDH. The non-American selections 51 and 970 also exhibited high levels of disease tolerance. Most susceptible were American clones 57845, ‘Augustine,’ Crandall, W590, and the American elm seedlings. The most disease-tolerant American elm selections identified in this study are being evaluated further for possible naming and release to the nursery industry.
Response of ‘Moonbeam’ Coreopsis and ‘Goldsturm’ Rudbeckia to B-Nine and Cycocel
Authors: Amling J.W. , Keever G.J. , Kessler J.R. , Eakes D.J. 
Published: August 2020

Abstract
Coreopsis verticillata ‘Moonbeam’ and Rudbeckia fulgida ‘Goldsturm’ were sprayed with tank mixes of B-Nine and Cycocel in all combinations of 0, 2500, 5000 or 7500 ppm B-Nine and 0, 1000, 1500 or 2000 ppm Cycocel. B-Nine was more effective in controlling height of both cultivars than Cycocel or B-Nine/Cycocel tank mixes. B-Nine alone suppressed height of coreopsis 26-52% (over all concentrations and all data collection dates), in contrast to a 17–41% height suppression when B-Nine was combined with Cycocel. Cycocel alone suppressed height of coreopsis 6–16% over all concentrations and data collection dates. B-Nine suppressed height of rudbeckia 20–40% over all data collection dates, while Cycocel suppressed height of rudbeckia only in the last two weeks of data collection (10 and 12% at weeks 8 and 9, respectively). Tank mixes applied to rudbeckia were not as effective as B-Nine alone for height suppression. Flowering of coreopsis was delayed 6 days by B-Nine and 12–14 days by tank mixes of B-Nine and Cycocel; Cycocel accelerated flowering up to 5 days when used alone. Flowering of rudbeckia was delayed up to 9 days with increasing B-Nine concentrations but was unaffected by Cycocel alone or tank mixes of B-Nine/Cycocel. No phytotoxicity was observed at the concentrations used.
Influence of Selected Surface Disinfestants, Fungicides, and Temperature on Seed Germination and Initial Growth of Southern Seaoats (Uniola paniculata)
Authors: Burgess Tyler L. , Blazich Frank A. , Nash David L. , Randall-Schadel Betsy 
Published: August 2020

Abstract
Seeds of southern seaoats (Uniola paniculata L.) were removed from storage at 4C (39F) and treated with the following selected surface disinfestants, fungicides, or combinations of these chemicals: nontreated (control), 1.3% sodium hypochlorite [NaOCl (chlorine bleach)], 2.6% sodium hypochlorite, RTU® (12.6% thiram + 0.34% thiabendazole), RTU®-PCNB (24% pentachloronitrobenzene), 1.3% sodium hypochlorite and RTU®, 2.6% sodium hypochlorite and RTU®, 1.3% sodium hypochlorite and RTU®-PCNB, or 2.6% sodium hypochlorite and RTU®-PCNB. Following treatment, seeds were germinated at an 8/16 hr thermoperiod of 35/20C (95/68F). The seed treatments and germination thermoperiod utilized were based on three preliminary trials that investigated the influence of selected surface disinfestants, fungicides, and temperature on seed germination of the species. Germination was recorded every 3 days for 30 days. Seed treatment was highly significant (P = 0.0001) for both total percentage germination and total percentage of decayed seeds. Germination of nontreated seeds was 45%, and four treatments resulted in germination &gt; 80% [RTU®-PCNB (81%), 2.6% sodium hypochlorite and RTU® (83%), 1.3% sodium hypochlorite and RTU® (87%), and 1.3% sodium hypochlorite and RTU®-PCNB (89%)]. A subsequent experiment investigated the effects of the aforementioned treatments with the exception of 1.3% sodium hypochlorite and RTU®, both used alone, on initial seedling growth of the species. Following treatment, seeds were sown in containers filled with a peat-based medium and the containers placed in a growth chamber maintained at an 8/16 hr thermoperiod of 35/20C (95/68F) with long day conditions. Emergence data were recorded every 3 days for 45 days. After 45 days, the study was terminated and additional data recorded to include plant height (height of main stem), leaf number, length and width of the two longest leaves, and top and root dry weights. Surface disinfestant, fungicide, and combination treatments were highly significant (P = 0.0004). Percentage emergence of nontreated seeds was 35% and five of the seven treatments resulted in emergence ≥ 75% [2.6% sodium hypochlorite (75%), 1.3% sodium hypochlorite and RTU® (75%), 1.3% sodium hypochlorite and RTU®-PCNB (76%), 2.6% sodium hypochlorite and RTU®-PCNB (81%), and 2.6% sodium hypochlorite and RTU® (83%)] with negligible effects on seedling growth. There were significant treatment differences regarding some of the variables used to evaluate seedling growth. In most cases these differences were due to seedlings from nontreated seeds having lower values for each measured variable than values for the same variables from treated seeds. Results of both experiments demonstrate the potential value of chemical seed treatment during production of seedling transplants of U. paniculata.
A New System to Monitor Water and Nutrient Use in Pot-inpot Nursery Production Systems
Authors: Zhu H. , Krause C.R. , Zondag R.H. , Brazee R.D. , Derksen R.C. , Reding M.E. , Fausey N.R. 
Published: August 2020

Abstract
Techniques are needed to monitor nursery production practices for proper use of water resources and nutrient management. An experimental system to examine water quality, irrigation efficiency and drainage from pot-in-pot nursery container production was established in a commercial nursery. The system mainly consisted of 50 pot-in-pot containers with 50 trees irrigated with micro spray stakes, drainage water measurement devices, container-substrate moisture probes, thermocouples, a weather station, and data loggers. Tests indicated the system was capable to measure irrigation and rainfall inputs, drainage water loss, container substrate moisture content and temperature, leachate of nitrogen, phosphate and potassium in drainage water, and tree growth in pot-in-pot nursery production. The system provided a method to not only monitor the loss of water and nutrients but also continuously monitor the substrate temperature and moisture content during four seasons of a year to evaluate potentials of winter injury or summer heat damage to roots for pot-in-pot nursery production.
Initial Plant Size and Landscape Exposure Affect Establishment of Transplanted Kalmia latifolia ‘Olympic Wedding’
Authors: Wright Amy N. , Warren Stuart L. , Blazich Frank A. , Harris J.Roger , Wright Robert D. 
Published: August 2020

Abstract
Effects of plant size and landscape exposure on survival and subsequent growth of transplanted, container-grown mountain laurel (Kalmia latifolia L. ‘Olympic Wedding’) were studied at two locations. Plants of ‘Olympic Wedding’ mountain laurel grown in 1, 7.5, or 19 liter (1 qt, 2 gal, or 5 gal) containers for 1,2, or 3 years, respectively, were transplanted in Raleigh, NC, and Blacksburg, VA, in tilled beds amended with pine bark along four exposures (north, south, east, and west). In Raleigh, survival increased with increasing container size with plants grown initially in 19 liter containers having the highest rate of survival whereas, survival was greatest on the east and north exposures and lowest on the west exposure. There was no difference in survival between container sizes or exposures for plants grown in Blacksburg. After three growing seasons in the landscape, visual ratings in Raleigh were higher for plants grown initially in 7.5 liter (2 gal) containers than for plants grown in 1 (1 qt) or 19 liter (15 gal) containers. Visual ratings were higher on north and east exposures than on south and west exposures regardless of container size. In Blacksburg, percent leaf scorch was lower for 1 and 7.5 liter (1 qt and 2 gal) plants, than for 19 liter (5 gal), and was highest on west exposures. Growth index (GI) increased 118% from 1999 to 2001 in Raleigh and 225% from 1999 to 2002 in Blacksburg for 1 liter (1 qt) plants and 51% in Raleigh and 78% in Blacksburg for 7.5 liter (2 gal) plants over the course of the experiment. There was an initial increase in GI for 19 liter (5 gal) plants in both locations, but in subsequent years GI decreased due to stem dieback. In Raleigh, GI of 7.5 liter (2 gal) and 19.5 liter (50 gal) plants grown on the east exposure was greater than plants grown on the south exposure with no difference due to exposure at Blacksburg. Results suggest that in climates similar to Raleigh, initial container size and exposure affect survival of transplanted mountain laurel, but in cooler climates like Blacksburg, initial container size and exposure may not be critical factors except in windy exposures.
Cotton Gin Compost as a Substrate Component in Container Production of Nursery Crops
Authors: Jackson Brian E. , Wright Amy N. , Cole David M. , Sibley Jeff L. 
Published: August 2020

Abstract
Shoot and root growth of plants grown in substrate blends containing cotton gin compost (CGC) were compared to plants grown in a traditional pine bark (PB) blend. In 2002 ‘Winter Gem’ boxwood, ‘Firepower’ dwarf nandina, and ‘Midnight Flare’ azalea were potted in four substrate blends containing by volume 6:1 PB:sand (S), 4.5:1.5:1 PB:CGC:S, 1:1 PB:CGC, or 1.5:4.5:1 PB:CGC:S. Plants were grown for nine months on a container pad in Auburn, AL. In 2003–2004 this study was repeated with ‘Renee Mitchell’ azalea as a replacement for ‘Midnight Flare’ azalea. Periodic growth measurements and a final visual root ball evaluation were conducted in each experiment. Substrates were analyzed to determine physical properties (air space, water holding capacity, total porosity, and bulk density) and chemical properties (pH and electrical conductivity). In both experiments, growth indices of all cultivars in substrates containing CGC were similar to or greater than those of the PB:S control blend. Visual quality of root systems was similar for all plants across all substrates.
Effects of Long-Term Recycled Wastewater Irrigation on Visual Quality and Ion Concentrations of Ponderosa Pine
Authors: Qian Y.L. , Fu J.M. , Klett J. , Newman S.E. 
Published: August 2020

Abstract
Recycled wastewater (RWW) has become a common water source for irrigating golf courses and urban landscapes. Ponderosa pine (Pinus ponderosa) is commonly used in urban landscape settings in the Rocky Mountain West. To evaluate the effects of RWW irrigation on quality and needle ion accumulations of ponderosa pine, eight landscape facilities near metropolitan Denver, CO, were selected for the experiment. Among these sites, four had been irrigated exclusively with domestic RWW [electrical conductivity (EC) = 0.84 dS/m] for 5, 6, 15, and 20 years, respectively. The other four with similar turf species, age ranges, and soil textures had been irrigated with surface water (EC = 0.23 dS/m). Ponderosa pines grown on sites irrigated with RWW exhibited 10 times higher needle burn symptoms than those grown on sites irrigated with surface water (33% vs. 3%). Tissue analysis indicated that ponderosa pine needles collected from sites receiving RWW exhibited 11 times greater Na+ concentration, 2 times greater Cl−, and 50% greater B concentrations than samples collected from the control sites. Stepwise regression analysis revealed that the level of needle burn was largely influenced by leaf tissue Na+ concentration. Tissue Ca level and K/Na ratio were negatively associated with needle burn symptoms, suggesting that calcium amendment and K addition may help mitigate the needle burn syndrome in ponderosa pine caused by high Na+ in the tissue.
Seedling Growth, Leaf Injury and Ion Uptake Response of Cold-Resistant Palm Species to Salinity
Authors: Khurram S. , Miyamoto S. 
Published: August 2020

Abstract
Palms are becoming popular landscape plants in the upper desert region of the Southwest where water used for irrigation has elevated salinity. An experiment was conducted in a greenhouse to evaluate leaf damage and growth response of nine cold-resistant palm species to salinity. One-year-old potted seedlings were transplanted to 10-liter containers filled with loamy sand and irrigated with saline solutions containing 800, 2000, 5000, and 7500 mg/liter of predominantly NaCl salts. The corresponding electrical conductivity was 1.2, 4.4, 9.4, and 13.7 dS/m, respectively. Seedlings were irrigated at a leaching fraction of 30 to 35% for six months, and leaf growth, leaf injury, and leaf mineral contents measured. Under this irrigation regime, salinity of irrigation solutions approximately equals salinity of the soil saturation extract. Leaf growth and leaf injury were highly species-dependent. A significant growth reduction and leaf injury of Sabal palmetto, Butia capitata, and Trachycarpus fortunei appeared when irrigated with the 4.4 dS/m solution, those of Trithrinax brasiliensis, Brahea armata, and Sabal minor when grown with the 9.4 dS/m solution, and Washingtonia filifera, Washingtonia robusta and Phoenix canariensis, using the 13.7 dS/m solution. Injured leaves of poorly-tolerant species contained unusually large amounts of Na (10 to 70 g/kg) when irrigated with the 9.4 dS/m solution. W. filifera, W. robusta, and P. canariensis seem to be ideal species for saline areas.
Root Pruning and Transplant Success for Cathedral Oak® Live Oaks
Authors: Gilman Edward F. , Anderson Patti J. 
Published: August 2020

Abstract
Trees that were root pruned regularly throughout the production period grew at a slower rate than trees that were not root pruned, but root pruning only in the last year of production did not affect trunk and canopy growth. Trees with root-pruning fabric installed under liners at planting grew at the same rate as trees without fabric during 39 months of field production. Hand spade root pruning throughout the production period increased the number of small diameter (&lt; 3mm) roots and decreased the number of large diameter roots in the root ball compared to trees that were not root pruned. Root pruning only in the last year of production reduced the number of large diameter roots but did not increase the number of small diameter roots. Fabric had no impact on the root system. Root pruning with a hand spade throughout production or only in the last year of production reduced water stress significantly in trees following digging compared to trees not root pruned during production. Root-pruning fabric installed under liners at planting reduced stress following digging 39 months later, but only on two of the days when water stress was measured.
Accumulation of a Protein Associated with Plant Defense in Powdery Mildew Resistant Dogwood (Cornus florida)
Authors: Mmbaga M.T. , Avila F.J. , Howard E.F. , Myles E.L. 
Published: August 2020

Abstract
This study was conducted to better understand the nature of powdery mildew resistance in flowering dogwood (Cornus florida L.) and in particular to determine if inducible plant defense proteins are associated with powdery mildew resistance. Results from this study showed an accumulation of a new protein in resistant plants, but not in susceptible plants that were challenged with powdery mildew pathogen (Erysiphe (Sect. Microsphaera) pulchra). The protein accumulated in a high level in the resistant selections at 48 hr after inoculation with the pathogen and that was consistent with the production of pathogenesis related (PR) proteins. The protein was characterized as having an isoelectric point of 7.5 ± 0.5 and molecular weight of 18 ± 2 KD. Partial sequence analysis of this protein revealed homology with PR-10 protein associated with drought resistance in potato and was analogous to other proteins related to resistance in other crops. Repeated analysis showed similar results and suggested that a biochemical mode of resistance involving plant defense proteins may be associated with powdery mildew resistance in flowering dogwood.
Postemergence Oxalis Control with Diuron: Minimizing Crop Injury with Timely Irrigation
Authors: Richardson Ben M. , Gilliam Charles H. , Wehtje Glenn R. , Fain Glenn B. 
Published: August 2020

Abstract
Experiments were conducted to evaluate tolerance of container nursery crop tolerance and yellow woodsorrel (Oxalis stricta) control with postemergence applied diuron as influenced by timely overhead irrigation. Intent was to identify an interval between application and irrigation that may reduce crop injury without compromising oxalis control. Diuron was applied at a common rate of 1.0 lb ai/A to oxalis and two nursery crops (Camellia sasanqua ‘Alabama Beauty’ camellia, and Rhododendron indicum ‘G.G. Gerbing’, azalea). Treatments consisted of irrigation at 1, 2, 4, 8, 12, 24, or 48 hr after application. Oxalis control was equivalent whether treated plants were irrigated within either 1 hr or 48 hr after application. Camellia exhibited no visible injury regardless of treatment. Azaleas exhibited diuron-induced injury, however injury was reduced if plants were irrigated within 1 hr of diuron application. 14C-diuron was used to determine the absorption rate of foliar-applied diuron into oxalis, camellia and azalea. Absorption by oxalis was relatively rapid, and reached a maximum (∼68% of applied) within 8 hr after application. Camellia and azalea absorbed a smaller percentage of the amount applied, and absorption was more protracted over time compared to oxalis. Azalea absorbed slightly more than camellia. Diuron has potential for use as an over-the-top application for postemergence oxalis control and timely irrigation has the potential to reduce injury to sensitive crops.
Seedling Populations Produced by Colored-leaf Genotypes of Japanese Barberry (Berberis thunbergii DC.) Contain Seedlings with Green Leaf Phenotype
Authors: Lehrer Jonathan M. , Brand Mark H. , Lubell Jessica D. 
Published: August 2020

Abstract
The leaf color of seedling populations derived from ornamental genotypes of Japanese barberry (Berberis thunbergii DC.) was evaluated to determine whether nursery selections of this important landscape plant could be expected to produce green-leaf progeny or seedlings with leaf color resembling the purple-leaf or yellow-leaf parent. This is a compelling inquiry since nearly all B. thunbergii plants found within invasive populations possess green foliage and the potential contribution of seedlings by ornamental purple-and yellow-leaf genotypes is unknown. Seed lots collected from cultivated barberry genotypes located in landscape settings were processed and raised in a greenhouse to observe leaf color phenotype. It was found that all genotypes studied produced at least some green seedlings. The percentage of green progeny produced varied widely by genotype. Green-leaf cultivars yielded close to 100% green seedlings and all purple-and yellow-leaf forms produced at least 20% green offspring. Among purple-leaf genotype accessions located adjacent to potential purple-leaf pollen donors, var. atropurpurea produced significantly fewer green seedlings (18.5%) than ‘Crimson Pygmy’ (71%) and ‘Rose Glow’ (45%). ‘Rose Glow’ individuals growing adjacent to other purple Japanese barberry forms produced significantly fewer green seedlings (45%) than ‘Rose Glow’ accessions that were isolated from additional purple Japanese barberry (88%). This study demonstrates that some invasive green-leaf B. thunbergii could be derived from popular garden forms since purple- and yellow-leaf genotypes readily produce green-leaf offspring which resemble feral barberry. These findings do not, however, provide any definitive link between cultivated and naturalized Japanese barberry.
Control of Northern Willowherb in Nursery Containers
Authors: Altland James , Cramer Eryn 
Published: August 2020

Abstract
Four experiments were conducted to determine the effectiveness of granular and sprayed preemergence herbicides for controlling northern willowherb (Epilobium ciliatum Rafin) in container crops. Eleven granular herbicides representing various combination of pendimethalin, prodiamine, oryzalin, oxyfluorfen, oxadiazon, napropamide, isoxaben, trifluralin, and flumioxazin were evaluated, as well as sprayed Surflan AS (oryzalin), Devrinol 50-DF (napropamide), Barricade 4FL (prodiamine), and Gallery 75DF (isoxaben). Herbicides were applied to recently filled containers and irrigated with overhead sprinklers. Weed numbers were counted in each pot and weed shoot dry weight was measured at the conclusion of each study. Ronstar G (oxadiazon) at 4.48 kg ai/ha (4 lb ai/A) consistently provided the most effective control among all herbicides. Other granular herbicides containing oxadiazon were also effective. Surflan and Devrinol did not consistently reduce weed numbers as effectively as Ronstar G, however they did reduce subsequent growth of northern willowherb seedlings that were able to successfully establish. Gallery did not provide any control alone nor did it improve control when tank mixed with other products.