bluuebunny/crossref_metadata_2025 huggingface dataset:
Host-Parasite Relationships of Susceptible and Resistant Elm Callus Cultures Challenged with Ophiostoma ulmi (Buisman) Nannf.
Authors: Krause C. R. , Ichida J. M. , Schreiber L. R. , Domir S.
Published: August 2020

Ultrastructural effects of Ophiostoma ulmi (Buisman) Nannf..(= Ceratocystis ulmi Buisman C. Moreau) on susceptible American elm (Ulmus americana L.) callus tissue consisted of extensive vacuolation, accumulation of cytolytic substances, and plasmolysis when viewed with electron and light microscopy. Infected resistant American elm callus tissue revealed slight cell wall damage with some phenolic-like deposits but adjacent cells, membranes, mitochondria and nuclei were intact. Fungal hyphae that adhered to callus grown from susceptible American elm plants were regularly observed. Sparse hyphal growth was not suspended above resistant American elm callus cells. Callus from nonhost and resistant elms showed reduced hyphal growth between host cells compared to susceptible elm with increased accumulation of extracellular, phenolic-like deposits than in callus of American elm. The fungal structures on resistant tissue showed evidence of irregular growth and morphology. The latter suggest a phytoalexin-like response by the resistant American elm callus tissue.
Vegetation Management Effects Growth of Leyland Cypress Grown for Christmas Trees
Authors: NeSmith D. Scott , Lindstrom Orville M.
Published: August 2020

Leyland Cypress trees x Cupressocyparis LeyLandii (A.B. Jacks. and Dallim.) Dallim. and A.B. Jacks. ‘Haggerston Grey’ were planted in the late winter of 1993 in a tall fescue (Festuca arundinacea Schreb.) sod. Vegetation-free circles of 0 (control), 0.6, 0.9, and 1.5 m (0, 2, 3 and 5 ft) diameters were maintained from 1993 to 1994 by a combination of commercially recommended herbicides and hand-weeding. The treatments resulted in vegetation-free areas of 0, 0.3, 0.6, and 1.8 m2 (0, 3, 7, and 19 ft2). Trees were mea sured over a 2 year period to determine the influence of vegetation-free area on growth. There were no differences in trunk cross sectional area or tree volume (calculated from height and width measurements) during 1993. By the spring of 1994, both trunk cross sectional area and tree volume increased with size of vegetation-free area. The influence of vegetation-free area on tree growth was even more pronounced by the fall of 1994. These results indicate vegetation control is important in establishing Leyland Cypress for Christmas trees. The optimum vegetation-free area appears to be between 0.6 m2 and 1.8 m2 (7 and 19 ft2) during the second year of growth.
Weed Control With Herbicide-Coated or -Blended Fertilizer in ‘August Beauty’ Gardenia
Authors: Crossan C.K. , Gilliam C.H. , Eakes D.J. , Keever G.J. , Wehtje G.R. , Dozier W.A.
Published: August 2020

Prostrate spurge (Euphorbia maculata L.) control and injury to container-grown ‘August Beauty’ gardenia (Gardenia jasminoides Ellis) were evaluated using Ronstar 50WP (oxadiazon) or Pennant 7.8E (metolachlor)-coated or Ronstar 2G (oxadiazon) or Pennant 5G (metolachlor)-blended Nursery Special 12N–2.6P–5.0K (12–6–6) fertilizer. Herbicides were applied at 4 rates, 2.3, 4.5, 9.0, and 18.0 kg ai/ha (2, 4, 8, and 16 lb ai/A) and compared to broadcast and spray applied pre-emergence herbicide applications at 4.5 kg ai/ha (4 lb ai/A). Ronstar (oxadiazon)-coated or -blended Nursery Special at all rates, except 2.3 kg ai/ha (2 lb ai/A) provided similar weed control to the broadcast or spray applied controls. Pennant (metolachlor)-coated or -blended fertilizer controlled spurge only at 18.0 kg ai/ha (16 lb ai/A). Weed control was similar when comparing herbicide formulation (coated vs. blended). Gardenia growth was similar among treatments and no injury symptoms were observed with any treatment.
Landscape Maintenance Firms: I. Business Features and Factors Influencing Industry Performance
Authors: Garber M.P. , Bondari K.
Published: August 2020

Seventy-two completed questionnaires sent to landscape maintenance firms in Georgia were received for a response rate of about 38%. Approximately two-thirds of the landscape maintenance firms were located in the metro Atlanta area and about 98% of their projects were in Georgia. Firms surveyed were involved primarily (approximately 95% of their projects) in outdoor maintenance activities, however, 50% of the large firms were involved in some level of indoor plant maintenance. Three size classes of firms were established based on their 1993 wholesale value of plant material purchased, small (<$25K), medium ($25K-$100K), and large (>$100K). The large firms accounted for 26% of the respondents, 72% of the gross revenue, and 79% of the plant materials purchased. Plant material purchased from growers (52.5%), rewholesalers (35.0%), brokers (8.5%), and garden centers (3.9%) accounted for 99.9% of plants purchased by landscape maintenance firms. Industry trends most frequently identified by respondents to have a positive impact on the industry over the next 5 years were: (1) an improving economy (38.7%), (2) consumer emphasis on plant quality (18.1%), and (3) alternative debris disposal such as composting and recycling (12.6%). The 3 trends with the greatest potential for negative impact on the industry were identified as: (1) unprofessional, new firms that submit unrealistic low bids (28.4%), (2) mandatory employee benefits and government regulations (22.7%), and (3) public concern regarding pesticide safety (17.0%).
Interior Plants May Improve Worker Productivity and Reduce Stress in a Windowless Environment
Authors: Lohr Virginia I. , Pearson-Mims Caroline H. , Goodwin Georgia K.
Published: August 2020

This study documents some of the benefits of adding plants to a windowless work place—a college computer lab. Participants' blood pressure and emotions were monitored while completing a simple, timed computer task in the presence or absence of plants. When plants were added to this interior space, the participants were more productive (12% quicker reaction time on the computer task) and less stressed (systolic blood pressure readings lowered by one to four units). Immediately after completing the task, participants in the room with plants present reported feeling more attentive (an increase of 0.5 on a self-reported scale from one to five) than people in the room with no plants.
Compost and Rubber Tire Chips as Peat Substitutes in Nursery Container Media: Effects on Chemical and Physical Media Properties
Authors: Jarvis Beth R. , Calkins James B. , Swanson Bert T.
Published: August 2020

Physocarpus opulifolius ‘Dart's Gold’, Forsythia x ‘Meadowlark’, Spiraea x billiardii, Juniperus chinensis ‘Seagreen’, J. sabina ‘Mini Arcade’, J. horizontalis ‘Hughes’, and Lamiastrum galeobdolon were grown in container media amended with three yard waste (YW) composts, one municipal solid waste (MSW) compost and shredded rubber tire chips. Each of the five amendments was used to replace 50% or 100% of the sphagnum peat in a standard container medium resulting in eleven media treatments. Effects of peat replacement with compost or tire chips were compared relative to chemical and physical media characteristics. Amendments evaluated had limited long term nutritional value. Initial pH was increased when peat was replaced with compost or rubber tire chips; the increase in pH was proportional to the amount of peat replaced (50 or 100%). Over time, pH of all media equilibrated with irrigation water pH. Soluble salts were reduced for media amended with rubber tire chips while peat replacement with compost had variable effects on soluble salt levels based on compost source. Media amended with compost exhibited increased bulk density and decreased porosity, water infiltration capacity and water holding capacity compared to the standard, peat-based control medium. Peat replacement with rubber tire chips increased bulk density and porosity and decreased water holding capacity compared to the standard control medium. Water infiltration capacity was greatly increased and water holding capacity decreased when peat was replaced 100% with rubber tire chips.
Rooting of ‘Brown Velvet’ Southern Magnolia Stem Cuttings as Influenced by Medium and Auxin Treatment
Authors: McCracken T. Patrick , Catanzaro Christopher J. , Bilderback Ted E.
Published: August 2020

Terminal stem cuttings of ‘Brown Velvet’ Southern magnolia (Magnolia grandiflora L. ‘Brown Velvet’) were treated with 0.3% indole-3-butyric acid (IBA) in talc, or 0.5% naphthaleneacetic acid (NAA) quick dip + 0.3% IBA in talc, or 0.5% NAA + 1.0% IB A quick dip. Rooting media included pine bark, perlite, or combinations of bark and perlite at the following ratios: 3:1, 1:1, 1:3 (by vol). Cuttings were rooted in a greenhouse mist bed supplied with bottom heat. Rooting percentage was unaffected by media with the exception of a decreased response in perlite. Root length and secondary root formation was greater with pine bark than with perlite, while the bark/perlite blends provided an intermediate response. Increased auxin concentrations produced more primary roots but reduced formation of secondary roots. However, rooting percentage was not affected by auxin treatment. Results suggest that medium selection is more important than auxin source or delivery method in the rooting of ‘Brown Velvet’ Southern magnolia.
Factors Influencing Seed Germination of Lupinus perennis
Authors: Mackay Wayne A. , Davis Tim D. , Sankhla Daksha , Riemenschneider Don E.
Published: August 2020

Seeds of Lupinus perennis Wats. (perennial lupine) were subjected to a variety of scarification and temperature treatments. Without scarification, <15% germination was observed within 1 week. Germination increased quadratically as the duration of acid scarification time increased. After 15 min scarification, nearly 90% of the seeds germinated and nearly 100 percent germination was obtained after 45 min scarification. Nicking the seed coats with a razor blade resulted in 100% germination. In contrast, soaking seeds in 22C (72F) water for 24 hr failed to enhance germination. Total germination of scarified seeds was >80% between 21 and 29C (70 and 85F) within 54 hr. The most rapid germination occurred within 24 to 29C (75 to 85F). At 32C (90F), total germination was reduced to approximately 60%. At temperatures ≥ 35C (95F), total germination was reduced to less than 4%. Germination occurred equally well in the light or dark. Our data indicate that seeds of L. perennis must be scarified to germinate and the most rapid germination occurs between 24–29C (75–85F).
Freezing Date and Duration Effects on Regrowth of Three Species of Container—grown Herbaceous Perennials
Authors: Perry Leonard P. , Herrick Todd
Published: August 2020

Three species of herbaceous perennials were transplanted from 400 cell-size plugs to 400-ml containers and grown in a glasshouse at 25C day/20C night (78/68F) ± 2C (4F) until October 10. At that time glasshouses were programmed for ambient outdoor temperatures, but maintained above 3C (38F) ± 2C at night. Plants were exposed in controlled programmable freezers to four freezing temperatures [−5,−5,−11 and −14C (23, 18,12,7F)] on November 15,1995, and January 1, 1996. Plants were allowed to remain at each temperature for either 30 or 120 minutes. Plants were then returned to the glasshouse, and rated for survival and salability following 6 weeks regrowth at 15C (59F). The rating scale was subjective and ranged from 1 to 5 (1 = worst, 5 = best, 3 and above considered salable). Regrowth means of all three species declined as treatment temperatures decreased. Although freezing date had a significant influence on regrowth quality of Aquilegia and Dianthus, only freezing duration influenced Dianthus regrowth. Neither factor significantly influenced regrowth quality of Lavandula. Treatment temperature and its interaction with freezing date or duration was statistically significant for all three species. All plants remained marketable following exposure to −11C (12F).
Effects of Plant Growth Regulators on Sturdiness of Jack Pine Seedlings
Authors: Schnurr Jeffrey P. , Cheng Zong-Ming , Boe Arthur A.
Published: August 2020

Seven growth regulators (ancymidol, 6-benzylaminopurine, ethephon, flurprimidol, mefluidide, paclobutrazol, and uniconizole) at various concentrations were studied for their effects on sturdiness of greenhouse grown seedlings of jack pine (Pinus banksiana Lamb.), measured by a single parameter, growth modification index. All growth regulators at certain concentrations were effective in reducing plant height but none increased stem caliper. Several growth regulators increased shoot-to-root dry weight ratio. Benzylaminopurine greatly modified growth characteristics and resulted in deformed seedlings. Uniconizole was most promising for producing sturdier seedlings of jack pine.
Biosolids Improve Rooting of Bougainvillea (Bougainvillea glabra) Cuttings
Authors: Atzmon Nir , Wiesman Zeev , Fine Pinchas
Published: August 2020

Cuttings of Bougainvillea glabra were placed in 80-ml (4.9 in3) containers containing rooting medium mixed with various concentrations of biosolids (1, 2.5, 5 and 7.5%) from two sources (Herzliyya and Haifa). Two biosolids-free control media were used (with or without addition of mini-Osmocote fertilizer). Half of the cuttings were treated with IBA. The rooting percentage was improved by adding biosolids to rooting media. Treating cuttings with IBA without biosolids was inferior to some of the biosolid treatments. Root development was significantly stimulated by the biosolids compared with a slow-release fertilizer treatment. However, the effect of biosolids on shoot development was slightly improved. Generally, high concentrations of Herzliyya biosolids showed the best results in rooting and growth, whereas Haifa biosolids were best at lowest concentrations.
Effects of Above-Ground Pot-in-Pot (PIP) Placement and Humic Acid Extract on Growth of Crape Myrtle
Authors: Schluckebier J.G. , Martin C.A.
Published: August 2020

Rooted cuttings of crape myrtle (Lagerstroemia indica L. × L. fauriei Koehne ‘Muskogee’) were potted into 3.8 liter (1 gal) black polyethylene containers and subjected for two months to one of three above-ground shielding treatments; containers placed pot-in-pot (PIP) for two months, containers exposed to direct sunlight for two months, or containers placed PIP for one month and then exposed to sunlight for one month (PIP/exposed). Mean daily maximum temperatures in rooting substrate of containers exposed to sunlight were as much as 16C (29F) higher than PIP containers. Plants in containers exposed to sunlight for two months had less total root and shoot length and higher concentrations of leaf nitrogen compared with the other two treatments. Plants were next transplanted into 27-liter (7-gal) polybags filled with a landscape substrate and fertigated with a humic acid extract at 0, 50, 150, or 300 μL/L for two additional months. The change in shoot and root length of plants previously placed PIP for two months responded in quadratic fashion to increased humic acid extract concentration levels; the most response occurred at about 50 μL/L while the highest concentrations inhibited post-transplant growth. Growth inhibition caused by heat stress as a result of exposure of container walls to insolation was still evident two months after transplanting.
Production of Six Woody Landscape Plants in Copper-coated and Styrene-lined Containers
Authors: Brass Thomas J. , Keever Gary J. , Gilliam Charles H. , Eakes D. Joseph , Hesselein Charles P.
Published: August 2020

Growth of Rhododendron L. ‘Hershey's Red’ (azalea), Magnolia grandiflora L. (magnolia), Ilex × meserveae S.Y. Hu. ‘Blue Princess’ (holly), Pittosporum tobira (Thunb.) Ait. (pittosporum), Gardenia jasminoides Ellis ‘August Beauty’ (gardenia), and Nerium oleander L. (oleander) were evaluated for 8 months in 3.8 liter (#1) containers treated with (+) or without (−) copper hydroxide (Cu) and with (+) or without (−) a styrene lining. Plants were then repotted into 10.3 liter (#3) untreated containers to determine treatment effects on root regeneration and shoot growth. In addition, azalea, gardenia, and holly were planted in the ground to evaluate root regeneration and shoot growth during landscape establishment. All species tested had less root growth at the substrate-container interface at the end of the first growing season when grown in Cu-treated containers. Other growth parameters measured (height, trunk diameter, growth index) varied among species in response to Cu treatment. One growing season (11 months) after repotting into 10.3 liter (#3) containers, all species had less surface root coverage when the original 3.8 liter (#1) container was Cu-treated. Dry weights of newly generated roots outside the original rootball of repotted or transplanted plants were not affected by Cu or styrene treatment, except for a lower root dry weight of holly when previously grown in +Cu containers. After repotting into larger containers, shoot growth in response to Cu was species-dependent. Transplanted azaleas had a lower growth index after transplanting from +Cu containers than from −Cu containers. Growth index of gardenia was increased after repotting into 10.3 liter (#3) containers from 3.8 liter (#1), styrene-lined containers; surface root coverage 5 months after repotting also was increased when plants were previously grown in styrene-lined containers. Oleander, holly, and magnolia previously grown for 8 months in 3.8 liter (#1), styrene-lined containers without Cu all had more surface root coverage after being grown for 11 months in 10.3 liter (#3) containers compared to plants grown in unlined containers.
Nitrogen Nutrition of Containerized Cupressus arizonica var. glabra ‘Carolina Sapphire’
Authors: Stubbs Hunter L. , Warren Stuart L. , Blazich Frank A. , Ranney Thomas G.
Published: August 2020

Rooted stem cuttings of ‘Carolina Sapphire’ smooth Arizona cypress [Cupressus arizonica var. glabra (Sudw.) Little ‘Carolina Sapphire’] grown in calcined clay in 3.8 liter (#1) containers were fertilized daily for 16 weeks with a complete nutrient solution containing 0, 20, 40, 80 or 160 mg N/liter supplied as ammonium nitrate. Plant heights and stem diameters were unaffected by N rate suggesting that a daily nutrient application of 20 mg N/liter was adequate for maximizing growth. Nitrogen fertilization increased heights and stem diameters by 71% and 56%, respectively, compared to the nontreated controls (0 mg N/liter). Even though shoot growth was unaffected by increasing N levels, foliage N concentration was positively correlated (r = 0.75, P < 0.0001) to N levels. As N concentration increased, total root area and total root length increased quadratically. Nitrogen fertilization increased root area and root length 119% and 108%, respectively, compared to the nontreated controls. Phosphorus concentration of shoots increased quadratically with increasing N levels. Nitrogen rate failed to affect K concentration of shoots. Shoot Ca and Mg concentrations decreased with increasing N levels.
BA Application Promotes Offset Formation in Hosta Cultivars
Authors: Garner James M. , Keever Gary J. , Eakes D. Joseph , Kessler J. Raymond
Published: August 2020

A foliar spray of 0, 1250, 2500, or 3750 ppm BA was applied to 10 hosta cultivars. BA application promoted offset formation in 8 cultivars at 30 days after treatment (DAT) and in all cultivars at 60 DAT. At 30 DAT, no offsets had formed in controls (0 ppm BA) of ‘Halcyon’ or ‘Samuel Blue’, but plants receiving 3750 ppm BA averaged 3.1 and 5.5 offsets, respectively. In the remaining cultivars at 30 DAT, maximum increases in offsets compared to controls ranged from 0.9 offset for ‘Stiletto’ to 6.2 offsets for ‘Hyacinthina’. Untreated plants of ‘Halcyon’ formed no offsets by 60 DAT, whereas plants receiving 3750 ppm BA averaged 3.8 offsets. In the remaining cultivars at 60 DAT, maximum increases in offsets compared to controls ranged from 2.1 offsets for ‘Great Expectations’ to 7.6 offsets for ‘Stiletto’. Offset stage of development, based on number of unfurled leaves, was more advanced in treated plants than in controls of two cultivars, less than that of controls in two cultivars, and similar to controls in the remaining cultivars. No phytotoxic symptoms were noted for any cultivar, and plant size was either increased or not affected by BA treatment.
Honeylocust Plant Bug and Leafhopper: Response to Water Stress and Cultivar
Authors: Smitley D. R. , Peterson N. C.
Published: August 2020

In East Lansing, Michigan, honeylocust plant bugs Diaphnocoris chlorionis (Say) hatch from overwintering eggs in early May when leaf buds open. They progress through five larval stages by the middle of June. Adults are active in late June and early July. Feeding injury to developing honeylocust foliage occurs throughout the period of larval and adult activity from early May until early July. The leafhopper, Macropsis fumipennis, has a similar life cycle except for the period of adult activity that extends until late July. Cultivars vary considerably in susceptibility to honeylocust plant bug: injury to ‘Halka’ and ‘Skyline’ was far more severe than to ‘Summerlace’ trees in the same randomized planting. Water stress had no effect on honeylocust plant bug, but leafhoppers (M. fumipennis) were less abundant on trees the year following severe water stress.
Use of Rapeseed Meal to Control Black Vine Weevil Larvae Infesting Potted Rhododendron
Authors: Elberson Leslie R. , McCaffrey Joseph P. , Tripepi Robert R.
Published: August 2020

Defatted rapeseed meal (RSM) from Brassica napus L. was applied as a mulch to potted rhododendron and strawberry (companion plants) infested with black vine weevil larvae to evaluate its potential as a natural soil fumigant. In the first year of study, three potting media (Sunshine® mix #1, 9:1 bark:sand, and 1:1 bark:peat [by vol]) were tested for their effects on larval survival. In the second year, 0, 50, 100, or 200 g (0, 1.8, 3.5, or 7 oz) of RSM were added to potted plants of rhododendron cv. ‘Ignatius Sargent’ grown in 1:1 bark:peat media in #1 (3-liter) containers. Meal was added approximately 16 weeks after planting rhododendron and strawberry plants. In the first study potting media type was found to have a significant effect on insecticidal activity of the meal resulting in a higher rate of larvae surviving in pots with Sunshine® mix than those with custom mixes of bark and sand or bark and peat. In the second study the highest rate of RSM, 200 g (7 oz)/l gal pot, reduced larval survival by 70% compared to the lowest rate, 50 g (1.8 oz) RSM, and the control. Shoot growth of rhododendron was unaffected by all rates of RSM, however strawberry leaf margins became necrotic with RSM rates of 100 (3.5 oz) and 200 g (7 oz). Rapeseed meal is toxic to black vine weevil larvae, but rates necessary for effective control in a nursery application may be too high for practical use.
Retail Garden Outlets: Plant Material Purchases and Trends
Authors: Garber M. P. , Bondari K.
Published: August 2020

A Georgia survey indicated that retail garden outlets purchased about 86% of plant material directly from growers. The estimated wholesale value of plants purchased by retail garden outlets represented in this survey was about $30M. The mean wholesale value of plants purchased by garden centers ($99K) greatly exceeded that of feed and seed ($22K) and hardware($24K) stores. The most important factor in selection of a plant supplier by a retail garden outlet was plant quality. The mix of plant material purchased varied with the type of retail outlet as did the information sources used to determine which plants to purchase. The marketing implications of these results for growers are discussed.
Performance of Landscape Plants from Northern Japan in the North Central United States
Authors: Widrlechner Mark P. , Hebel James B. , Herman Dale E. , Iles Jeffery K. , Kling Gary J. , Ovrom A. Paul , Pair John C. , Paparozzi Ellen T. , Poppe Steven R. , Rose Nancy , Schutzki Robert E. , Tubesing Charles , Wildung David K.
Published: August 2020

In 1984 and 1985, 21 landscape plant introductions from northern Japan were distributed for testing in the NC-7 Regional Ornamental Plant Trials. Seventeen of these introductions were evaluated for 10 years at six to ten sites representing a cross-section of growing conditions in the north central United States. For these 17 introductions, first-year survival averaged 60%; however, by year 10, fewer than 20% of the original 425 plants were alive. Based on these evaluations, the populations could be divided into four groups. One population of Rosa rugosa was adapted to most trial sites; two populations (Alnus hirsuta and Lonicera chrysantha) were adapted to some sites; three populations were of poorly adapted dieback shrubs, and the remaining 11 populations included a diverse set of trees and shrubs unadapted to any, or nearly any, trial site. Temperature and moisture data from Japan and from trial sites were used to examine relationships between plant adaptation and climate. Statistically significant, multiple-regression models were calculated to describe the functional relationships between temperature and moisture conditions and plant adaptation at the various trial sites. Our models predict that plants from northern Japan are best adapted to sites in the northeastern United States where moisture surpluses exceed those typically found in the north central United States. These models also suggest criteria to evaluate sites throughout northeastern Asia for future exploration.
Low pH Enhances Rooting of Stem Cuttings of Rhododendron in Subirrigation
Authors: Holt Thomas A. , Maynard Brian K. , Johnson William A.
Published: August 2020

Semi-hardwood terminal stem cuttings of Rhododendron L. ‘P.J.M.’, R. ‘Catawbiense Album’ and R. ‘Purple Gem’ were treated with a solution of 0.1% indolebutyric acid and 0.5% napthaleneacetic acid and inserted into perlite for rooting under subirrigation, without overhead mist, at solution pH of 4.5 or 7.5. All cultivars rooted in higher percentages and produced larger root balls at pH 4.5 than at pH 7.5. A second study with softwood stem cuttings of R. ‘P.J.M.’ and both softwood and semi-hardwood stem cuttings of R. ‘Purple Gem’ confirmed these findings and included an additional subirrigation treatment, a sphagnum peat slurry, pH 4.1, which produced nearly identical results to the pH 4.5 treatment.
Tolerance of Seashore Paspalum Cultivars to Preemergence Herbicides
Authors: Jack Johnson B. , Duncan Ronny R.
Published: August 2020

The efficacy of preemergence herbicides among seashore paspalum (Paspalum vaginatum Swartz) cultivars used for summer annual weed control is limited. No differences were found in turfgrass tolerance among four paspalum cultivars from preemergence herbicides during 1996 and 1997 at Griffin, GA. The tolerance of paspalum turfgrass was good when treated with Ronstar (oxadiazon) at rates ≤ 10.1 kg/ha (9.0 lb/A), pendimethalin (various trade names, water-dispersible granules) or Barricade (prodiamine) at recommended rates [3.4 kg/ha (3.0 lb/A) and 0.8 kg/ha (0.7 lb/A), respectively]. When rates of these herbicides were increased to three times recommended, 15% injury was noted. During May 1996, Dimension (dithiopyr) injured the turf 12% when applied at the normal rate [0.6 kg/ha (0.5 lb/A)], but the injury was 35% in plots treated with three times recommended. Dimension did not cause any injury in 1997. Surflan (oryzalin) at 3.4 kg/ha (3.0 lb/A) and XL (benefin + oryzalin) at 3.4 kg/ha (3.0 lb/A) caused a maximum of 26% and 20% injury, respectively, when applied at the recommended rates. Maximum injury ranged from 48% for Surflan and 38% for XL when applied to plots at the three times recommended. The quality of PI 509018-1, SIPV-2, and AP-10 was generally higher than Adalayd from early spring until late August both years.
Influence of Herbicides on Establishment of Eight Seashore Paspalum Cultivars
Authors: Johnson B. Jack , Duncan Ronny R.
Published: August 2020

Herbicide efficacy among seashore paspalum (Paspalum vaginatum Swartz) ecotypes during establishment is not well documented. When herbicides were applied to eight newly planted paspalum cultivars, herbicide tolerance among cultivars was not different. Neither Manage (halosulfuron) at ≤0.21 kg/ha (≤0.19 lb/A) nor Ronstar (oxadiazon) at ≤10.0 kg/ha (≤9.0 lb/A) caused significant turfgrass injury when applied at the recommended or three times the recommended rates during 1996 and 1997. Similar results were obtained from Drive (quinclorac) at 0.9 kg/ha (0.8 lb/A) and Vanquish (dicamba) at 0.6 kg/ha (0.5 lb/A). In 1996, Dimension (dithiopyr) and pendimethalin (various trade names, water-dispersible granules) applied at any rate did not significantly injure the turf. However, when recommended rates were applied in 1997, Dimension (dithiopyr) caused a maximum of 19% injury [0.6 kg/ha (0.5 lb/A)] and pendimethalin caused a maximum injury of 23% [3.3 kg/ha (3.0 lb/A)]. The injury was 35 to 36% when each herbicide was applied at three times the recommended rate. Illoxan (diclofop) at ≥1.1 kg/ha (≥1.0 lb/A) was the only herbicide included in this study that severely injured the turfgrass (26 to 42%) both years when applied at the recommended rate. Differences were found in growth among eight paspalum cultivars during the 6-week period following planting. By 6 weeks, SIPV-2 generally produced the poorest growth in 1996 while Adalayd produced the poorest growth in 1996 and 1997.
Effects of Nitrogen Supply on Growth and Nutrient Status of Containerized Crape Myrtle
Authors: Cabrera Raul I. , Devereaux Diana R.
Published: August 2020

Containerized crape myrtle (Lagerstroemia indica x fauriei ‘Tonto’) plants were grown over a 9-month period using complete nutrient solutions, except during overwintering, that differed in N concentration: 15, 30, 60, 120, 210, and 300 mg/liter. Plant shoot biomass, leaf area and canopy diameter increased with applied N concentrations ([N]a) up to 60 mg/liter, but higher levels caused significant depressions in all these parameters. Root biomass and plant height were depressed linearly with increases in [N]a. Regardless of final plant biomass, increases in [N]a significantly favored shoot over root growth, with ratios increasing from 1.9 to 5.4 for 15 to 300 mg/liter, respectively.

Soluble salts in the medium, monitored via leachates, increased with N supply and were identified as a key factor involved in the yield reductions observed at the higher [N]a. Leaf N concentration increased with N supply, stabilizing at [N]a above 120 mg/liter; concentrations of 2.6–2.7% were associated with maximum growth. Calcium and iron concentrations in tissue followed the same response pattern as N, but sulfur (S) decreased significantly in an opposite pattern. Other nutrients did not respond to [N]a. Leaf tissue N:S ratios were more closely correlated with plant growth that either N or S alone, with maximum growth observed at a ratio of approximately 6:1. Higher N:S ratios produced sharp yield depressions.
Fertilizer Rate and Pot-In-Pot Production Increase Growth of Heritage River Birch
Authors: Ruter John M.
Published: August 2020

A study was conducted to compare the effects of three fertilizer rates [High N Southern Formula, 23N–1.7P–6.6K (23–4–8) at 1.3, 1.7, and 2.0 kg N/m3 (2.2, 2.8, and 3.4 lb N/yd3)] and two production systems [pot-in-pot (PIP) or conventional above-ground (CAG)] on the growth of Heritage river birch (Betula nigra L. ‘Cully’) in 26 liter (#7) containers. Plants grown PIP had greater shoot dry weight (20%), root dry weight (31%), total biomass (27%) and root:shoot ratios (12%). Increasing fertilizer rates increased shoot dry weights but decreased root:shoot ratios. Rate of fertilizer application influenced foliar Mg, Zn, and Fe while production system had no effect. The foliar P:Zn ratio increased linearly as rate of fertilizer increased. Soluble salts and NO3-N in the leachate increased linearly as rate of fertilizer increased at 15 and 60 days after application (DAA), whereas the response was curvilinear at 120 DAA. When different, nutrient concentrations in the leachate were greater for plants grown CAG. Fertilizer longevity based on prill analysis was greater when the PIP system was used, presumably due to lower substrate temperatures during the experimental period.
Susceptibility of Crapemyrtle Cultivars to Powdery Mildew and Cercospora Leaf Spot in Alabama
Authors: Hagan A. K. , Keever G. J. , Gilliam C. H. , Williams J. D. , Creech G.
Published: August 2020

Reaction of 43 cultivars in three crapemyrtle taxa (Lagerstroemia indica, L. indica x fauriei and L. fauriei) to powdery mildew (Erysiphe lagerstroemia) and Cercospora leaf spot (Cercospora lythracearum) was evaluated for three years in a simulated landscape planting in Auburn, AL. Overall, the incidence of powdery mildew was lower on L. indica x fauriei and L. fauriei than on L. indica. In two of three years, Cercospora leaf spot severity was similar among all cultivars of L. indica and L. indica x fauriei, while the single selection of L. fauriei ‘Fantasy’ proved highly resistant to this disease. Selected cultivars in each crapemyrtle taxa were resistant to one or both diseases. Over the three-year evaluation period, hybrid cultivars ‘Tuscarora’, ‘Tuskegee’, and ‘Tonto’, as well as L. fauriei ‘Fantasy’ were largely free of powdery mildew and suffered little damage from Cercospora leaf spot. Cultivars suffering light injury to the foliage along with little noticeable defoliation from either disease were L. indica x fauriei ‘Basham's Party Pink’, ‘Apalachee’, ‘Caddo’ as well as L. indica ‘Cherokee’ and ‘Glendora White’. Lagerstroemia indica ‘Carolina Beauty’, ‘Wonderful White’, ‘Raspberry Sundae’, ‘Powhatan’, ‘Peppermint Lace’, ‘Majestic Beauty’, and ‘Orbin Adkins’ were susceptible to both powdery mildew and Cercospora leaf spot. The mildew-resistant cultivars ‘Acoma’, ‘Near East’, ‘Yuma’, ‘Souix’, ‘Hopi’, and ‘Comanche’ suffered extensive spotting of the leaves, which extended well into the mid-canopy, along with heavy leaf shed due to Cercospora leaf spot. Cultivars which are susceptible to one or both diseases would be poor choices in low maintenance commercial or residential landscapes.
Control of Basal Sprout Regrowth in ‘Bradford’ Pear with NAA
Authors: Keever Gary J. , Stephenson James C. , Fare Donna C.
Published: August 2020

Suppression of basal sprout development in Pyrus calleryana Decne. ‘Bradford’ was achieved with naphthaleneacetic acid (NAA) applied as a dormant, directed trunk spray. Nearly complete sprout control was achieved with all test rates (2875 to 11,500 ppm) through 120 days after treatment (DAT), with a slight increase in total sprout number occurring between 120 and 210 DAT. The 5750 ppm rate provided optimal sprout control and resulted in 15% more increase in tree height and 20% more increase in caliper than in control trees. No phytotoxicity was observed on trees in any treatment.
Are ‘Barton’ and ‘Cloud 9’ the Same Cultivar of Cornus florida L.?
Authors: Windham Mark T. , Trigiano Robert N.
Published: August 2020

Ten flowering dogwood (Cornus florida) cultivars were evaluated for phenotypic characters including resistance to spot anthracnose and dogwood canker, susceptibility to frost damage, leaf color, bract length and color, bloom number and reproductive phenology. Cultivars differed by at least three phenotypic characters except for ‘Barton’ and ‘Cloud 9’, which when compared with each other, were not significantly different at any characteristic. DNA amplification fingerprinting (DAF) using 17 octamer oligonucleotide primers could not distinguish these cultivars. Furthermore, arbitrary signatures from amplification profiles (ASAP), a technique that produces ‘fingerprints of fingerprints’, which is capable of detecting more differences than DAF, also failed to reveal any polymorphic DNA. Therefore, based on the lack of phenotypic and genetic differences between these two cultivars, we conclude that they are the same genotype.
Irrigation Volume, Application, and Controlled-release Fertilizers: I. Effect on Plant Growth and Mineral Nutrient Content in Containerized Plant Production
Authors: Groves Kelly M. , Warren Stuart L. , Bilderback Ted E.
Published: August 2020

An experiment with four volumes of irrigation and five controlled-release fertilizers (CRFs) was conducted to evaluate effects on plant growth and mineral nutrient content. Rooted cuttings of Cotoneaster dammeri ‘Skogholm’ and seedlings of Rudbeckia fulgida ‘Goldsturm’ were grown in 3.8 liter (4 qt) containers in a pine bark:sand substrate (8:1, by vol) incorporated with 3.5 g (0.12 oz) N per container with one of the following five CRFs: Meister 21N–3.5P–11.1K (21–7–14), Osmocote 24N–2.0P–5.6K (24–4–7), Scotts 23N–2.0P–6.4K (23–4–8), Sustane 5N–0.9P–3.3K (5–2–4) or Woodace 21N–3.0P–9.5K (21–6–12). Irrigation volumes of 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in), or 1200 ml (1.7 in) were applied once daily (single) or in two equal applications with a two hr interval between irrigation allotments (cyclic). All measured variables were unaffected by irrigation application (cyclic or single). Top dry weight of cotoneaster increased quadratically with increasing irrigation volume for all CRFs. Maximum top dry weight was obtained with 612 ml (0.8 in), 921 ml (1.3 in), 928 ml (1.3 in), 300 ml (0.6 in), or 909 ml (1.3 in) for plants fertilized with Meister, Osmocote, Scotts, Sustane, and Woodace, respectively. Osmocote, Scotts, and Woodace produced 90% of maximum top weight over a wide range of irrigation volumes [≈ 550 ml (0.8 in) to 1200 ml (1.5 in)]. Stomatal conductance of cotoneaster fertilized with Osmocote 24–4–7 increased linearly with increasing volume of irrigation, whereas net photosynthetic rate increased quadratically and was highest at 800 ml (1.1 in). All CRFs, excluding Sustane, had similar dry weights when irrigated with 200 ml (0.3 in). At 800 ml (1.1 in) and 1200 ml (1.7 in), cotoneaster fertilized with Osmocote 24–4–7 and Scotts 23–4–8 produced greater top dry weight compared to Meister, Sustane, and Woodace. Top dry weight of rudbeckia increased quadratically with increasing irrigation volume regardless of CRFs. Maximum dry weight was produced with 1160 ml, 931 ml, 959 ml, 1091 ml, or 1009 ml for plants grown with Meister, Osmocote, Scotts, Sustane, or Woodace, respectively. Ninety percent of the maximum top dry weight of both species within each CRF could be obtained with a 40% reduction in irrigation volume. Nitrogen content of cotoneaster and rudbeckia were unaffected by irrigation volume, whereas P and K content, depending upon CRF and plant, was reduced at low irrigation volumes.
Evaluation of Various Traits of 40 Selections and Cultivars of Red Maple and Freeman Maple Growing in Maryland
Authors: Townsend A. M. , Douglass L. W.
Published: August 2020

Thirty-seven red maple (Acer rubrum L.) and three Freeman maple (A. x freemanii E. Murray) selections and commercial cultivars were evaluated for six years in a replicated field plot at Glenn Dale, MD. Significant differences among clones occurred for growth rate; for time, intensity, and duration of autumn color; for time of growth initiation in the spring; and for injury sustained from potato leafhopper (PLH) [Empoasca fabae (Harris)] feeding. The red maple cultivars showing the best red color over three years time were ‘Autumn Flame,’ ‘Brandywine,’ ‘Cumberland,’ ‘Red Rocket,’ ‘Somerset,’ ‘Sun Valley,’ and ‘Van.’ The cultivar ‘Bowhall’ was the least reddish. Of the three Freeman maples evaluated, ‘ Jeffersred’ and ‘Indian Summer’ manifested the best red color and also low PLH injury; whereas ‘Armstrong’ consistently showed the least reddish color of all 40 clones tested, and intermediate PLH injury. Those cultivars and selections from northern seed sources reached their peak color the earliest, but often dropped their leaves more quickly after showing their best color, compared to clones originating in more southerly locations. The clones showing the least PLH injury over several years included the Freeman maples ‘Jeffersred’ and ‘Indian Summer,’ and red maple clones and cultivars selected by the U.S. National Arboretum either from full-sib progenies (e.g., ‘Brandywine,’ ‘Somerset,’ ‘Sun Valley’) or from an Ohio provenance-progeny test (e.g., ‘Cumberland,’ ‘Red Rocket’). Those clones initiating growth (or “flushing”) earliest in the spring generally showed the least PLH injury; correlations between lateness of flushing and degree of PLH injury were highly significant.
Propagation of Thuja x ‘Green Giant’ by Stem Cuttings: Effects of Growth Stage, Type of Cutting, and IBA Treatment
Authors: Griffin Jason J. , Blazich Frank A. , Ranney Thomas G.
Published: August 2020

Stem cuttings of Thuja L. x ‘Green Giant’ (‘Green Giant’ arborvitae), consisting of 22 cm (8.6 in) terminals (tips of first-order laterals) or 20 cm (7.8 in) laterals (side shoots removed from those portions of terminal cuttings inserted into the rooting medium), were collected on three dates associated with specific stock plant growth stages (softwood, semi-hardwood, and hardwood) and treated with indolebutyric acid (IBA) in 50% isopropanol ranging from 0 to 9000 ppm (0.9%). Regardless of cutting type or auxin treatment, cuttings rooted in high percentages at each growth stage. Overall rooting for softwood, semi-hardwood, and hardwood, cuttings was 85%, 86%, and 96%, respectively. Semi-hardwood cuttings were the only cuttings in which percent rooting was affected by IBA treatment or cutting type, with lateral cuttings rooting in higher percentages than terminal cuttings (92% vs. 79%, respectively), while IBA concentrations of 3000 (0.3%) or 6000 ppm (0.6%) proved optimal for both cutting types. Mean root number and mean root length varied by growth stage, cutting type, and IBA concentration. In general, rooting percentages and root length were optimized at the hardwood stage with either cutting type treated with 3000, 6000 or 9000 ppm (0.3%, 0.6% or 0.9%) IBA, resulting in >10 roots per cutting.
Public Perceptions of Landscape Design as a Nursery Industry Service and Quality-of-Life Enhancement Factor
Authors: Rodie Steven N. , Paparozzi Ellen T.
Published: August 2020

Using a focus group approach, Midwest homeowners in Lincoln and Omaha, Nebraska, with recent experience and exposure to landscape design services were interviewed to assess their perceptions of the quality of available design services. In general, participants were pleased with their design experience and the quality of service provided to them. Poor communication between participants and landscape designers or landscape architects was commonly voiced as a key service limitation. Lack of homeowner knowledge of the design process was also identified as a limitation to good design, but to a lesser extent. Additionally, participants identified a variety of correlations between their landscapes and the potential for enhanced quality-of-life (QOL). Although not typically perceived as a critical singular QOL enhancement factor such as availability of food or medical care, quality landscape design appears to cumulatively enhance QOL in a significant way due to the wide variety of human needs that well-designed outdoor spaces can address.
Landscape Quality and the Price of Single Family Houses: Further Evidence from Home Sales in Greenville, South Carolina
Authors: Henry Mark S.
Published: August 2020

In this study, the contribution of the quality of landscaping to house prices was estimated for a sample of 218 home sales in Greenville, SC, from 1996 to 1997. The estimates were made using regressions of house price on house characteristics, location and landscape quality. The results obtained in this research were similar to an earlier study of Greenville home sales, from 1991 to 1993. For homes with the same square footage and other house characteristics, selling prices were 6% to 7% higher if landscaping quality was judged excellent rather than good. The price premium obtained by upgrading landscaping from average to good was approximately 4% to 5%.
Response of ‘Foxy’ Foxglove to GA3 and Cold Treatment
Authors: Keever Gary J.
Published: August 2020

A single foliar spray of 10–50 ppm GA3 promoted earlier (up to 30 days), more uniform flowering with higher flower counts per infloresence in ‘Foxy’ foxglove. Treated plants were compact with attractive foliage and considered marketable. Plants treated with higher rates of GA3 (75–1,000 ppm) formed excessively elongated inflorescences with malformed flowers and thin, strap-like, light green foliage. Cold treatment at 4.4C (40F) for 4 weeks shortened time to flower 8 and 6 days compared to that of plants cooled for 0 and 2 weeks, respectively. In the absence of GA3, cold treatment increased the number of inflorescences compared to plants not cooled.
Germination of Stewartia pseudocamellia Seeds is Promoted by Desiccation Avoidance, Gibberellic Acid Treatment, and Warm and Cold Stratification
Authors: Oleksak Brian A. , Struve Daniel K.
Published: August 2020

Japanese Stewartia, Stewartia pseudocamellia (Maxim.), seeds were extracted from immature capsules and handled under nondesiccating conditions. Moisture content of fresh seeds was 82%. After exposing seeds for 48 hrs at room conditions seed moisture content was 56% and after 24 hrs at 80C (176F) it was 49%. Both ambient and 80C (176F) drying conditions resulted in complete loss of viability based on a tetazolium test. Exposing seeds to a 24 hr aerated water soak in 1 mM gibberellic acid (GA3), and a 3 month warm (25C, 77F) stratification period increased seed germination only after 6 months of cold (4C, 40F) stratification compared to seeds given a 24 hr aerated water soak without GA3 and similar warm and cold stratification periods. Best management practices for handling and germination of fresh Japanese Stewartia seeds are: (a) harvest seed capsules when they turn from green to brown, (b) maintain seeds under nondesiccating conditions, (c) treat seeds with a 24 hr aerated water soak in 1 mM GA3 before a 3-month warm stratification, and (d) provide at least 7 months cold stratification.
Survival and Growth of Stewartia pseudocamellia Rooted Cuttings and Seedlings
Authors: Struve Daniel K. , Lagrimini L. Mark
Published: August 2020

Japanese Stewartia, Stewartia pseudocamellia (Maxim.), cuttings were rooted and seeds germinated to compare growth and survival of the two plant types. Softwood cuttings collected from 18-month-old, 1 to 1.3 m (3 to 4 ft) tall stock plants were rooted successfully (greater than 64%) at two propagation times by giving severed cuttings a basal quick dip in 0.1 M ascorbic or caffeic acid, before a basal quick dip in 100 ppm indolebutyric acid (IBA). Cuttings were overwintered in either a minimum heat (3C, 35F) polyhouse (89% survival), or in a 7C (45F) cooler (97% survival). There was no difference in height following overwintering, but by the end of the first growing season following propagation, seedlings were significantly taller than rooted cuttings, 84 vs 72 cm (33 vs 28 in), respectively. Although growth was vigorous, survival after upcanning was poor; rooted cutting survival was 17%, seedling survival was 48%. This study demonstrates that Japanese Stewartia can be propagated readily by softwood and semi-hardwood stem cuttings dipped in low IBA concentrations if cuttings are pre-treated with either ascorbic or caffeic acid. These cuttings can also be overwintered successfully.