bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Cultivar and Insecticide Choice on Oleander Aphid Management and Arthropod Dynamics on Asclepias Species
Authors: Braman S. Kris , Latimer Joyce G.
Published: August 2020

Performance of oleander aphid (Aphis nerii Boyer de Fonscolmbe) and large milkweed bug (Oncopeltus fasciatus Dallas) on 21 species of Asclepias was evaluated in a two-year field study. Season-long pest and beneficial insect population growth was monitored. Plant quality ratings also were obtained. Relative numbers of Monarch butterfly (Danaus plexippus (Linnaeus)) larvae were also recorded. All milkweed species supported growth and development of oleander aphid except A. vestita, which failed to establish in this study. The only species that did not become infested with milkweed bugs were A. syriaca and A. sullivantii. The plant species with the lowest number of aphids, the highest plant quality ratings and the highest number of Monarch larvae (which is desirable as a larval food plant for the butterflies) was gooseplant, A. physocarpa. A.tuberosa cultivars also ranked high among all species tested.

Five insecticides were tested for efficacy against the Oleander aphid. All insecticide products evaluated: Endeavor (pymetrozine), Orthene (acephate), Merit (imidacloprid), Tempo (cyfluthrin) and Mpede (insecticidal soap) resulted in short-term reductions in aphids in field plots during 1999. Reinfestation occurred within two to three weeks. Parasitoids and predators were also suppressed to varying degrees by materials applied.
Growth and Mortality of Dogwood Cultivars in Alabama
Authors: Hardin B. R. , Eakes D. J. , Gilliam C. H. , Keever G. J. , Williams J. D.
Published: August 2020

An open-field evaluation of 38 dogwood (Cornus) cultivars was conducted in central Alabama from May 1996 to March 1998. Mortality increased dramatically in giant dogwood (C. controversa Hemsl.), kousa dogwood cultivars (C. kousa Hance), and kousa x flowering dogwood hybrids (C. kousa x florida) from August 1996 to August 1997. Little mortality was observed for the flowering dogwood selections (C. florida L.) during this same period. Further characterization, based on height and stem diameter increases, was conducted on 23 flowering dogwood cultivars. Greatest average annual height and stem diameter increases for cultivars with white bracts and green foliage were observed in ‘Cloud 9’, ‘Fragrant Cloud’, ‘Ozark Spring’, ‘Springtime’, ‘Weaver’, ‘Welch Bay Beauty’, and ‘World's Fair’. Lowest average annual height and stem diameter increases occurred with ‘Autumn Gold’ and Wonderberry®. Among the selections with red or pink bracts and green foliage, ‘Stoke's Pink’ and ‘Welch's Junior Miss’ had greater annual average increases in height and stem diameter than ‘Purple Glory’. Annual average increases in height and final heights were similar among all cultivars with variegated foliage, with ‘First lady’ showing the greatest annual average increase in stem diameter and final stem diameter.
Susceptibility of Eight Herbs to Common Root-Knot Nematodes
Authors: Walker Jerry T.
Published: August 2020

Eight herb species were inoculated with two common species of root-knot nematode and grown for 2 months in a greenhouse. Root systems were examined for galls and egg mass production. All herb species were susceptible but developed fewer galls and had lower gall indices than Rutgers tomato. Burnet, chives, valerian and winter savory had few galls or low gall indices. Eggs were produced on all. Chamomile had a high gall index. Chicory, parsley, and sorrel had intermediate indices. Herbs were equally susceptible to the southern (Meloidogyne incognita) and peanut root-knot nematodes (M. arenaria), particularly at the highest inoculum densities. Mean dry weights of inoculated herbs were not always significantly less than the non-inoculated plants, suggesting that some herbs may be tolerant to root-knot nematodes.
Rapid Determination of Nitrogen Status in Annual Vinca
Authors: Altland James E. , Gilliam Charles H. , Edwards James H. , Keever Gary J. , Fare Donna C. , Sibley Jeff L.
Published: August 2020

Three experiments were conducted to develop a method for rapid determination of nitrogen (N) status in ‘Pacifica White’ vinca (Catharanthus roseus (L.) G. Don). In experiment 1, N was applied to potted vinca at 40, 80, 120, or 160 ppm N to produce plants ranging from N deficient to N sufficient. Data were collected 14, 28, and 42 days after treatment (DAT) and included flower number, growth index [(height + width + width) ÷ 3], and from recently matured foliage the following parameters: SPAD-502 readings, petiole sap nitrate (SN) concentration, and total-N (percent of dry weight) (FN). Experiment 2 was similar with the exception that N rates applied were 30, 60, 90, 120, 150, or 180 ppm N, and data were collected 14, 29, and 42 DAT. In experiment 3, N was applied at 0, 90, or 180 ppm N and data were collected 0, 4, 7, 10, and 14 DAT. In experiments 1 and 2, SPAD readings were poorly correlated to FN (correlation coefficients ranged from 0.35 to 0.88) and the relationship between FN and SPAD readings changed at different collection dates. Petiole sap nitrate concentration determined by a Cardy nitrate meter was highly correlated throughout the three experiments. Above 380 ppm SN, the relationship between FN and SN was determined to be: SN/1000 = 2.3 × FN-4.8 (r2 = 0.73, n = 104). In experiment 3, FN and SN readings were able to detect N deficiency in vinca by 4 DAT, despite lack of visual symptoms until 14 DAT. SPAD readings were not suitable for predicting FN and plant N status. SN was a reliable predictor of FN and thus could be used to rapidly determine plant N status.
Plant Susceptibility to and Seasonal Occurrence of Phaedon desotonis Balsbaugh, a Leaf Beetle Attacking Coreopsis
Authors: Kris Braman S. , Pendley Andrew , Corley Will
Published: August 2020

Phaedon desototonis Balsbaugh, a leaf beetle, occurred in large numbers in plantings of wildflowers in central Georgia. Although the species was previously considered rare, large populations of the beetle were associated with Coreopsis spp. Peak larval abundance occurred in April, while greatest numbers of adults were observed in May. One generation was observed. Thirty-eight plant taxa in 11 families were evaluated for susceptibility to feeding and injury by the beetle. The composits Coreopsis lanceolata (L.), Coreopsis tinctoria Nuttall, C. verticillata (L.), and Bidens aristosa (L.) were consistently fed on by adults and larvae of P. desotonis. Of those plants, B. aristosa was the least preferred and least damaged.
Ethephon Suppresses Flowering and Improves the Aesthetic Value of Purple Passion Plant (Gynura aurantiaca)
Authors: Chen Jianjun , Henny Richard J. , Caldwell Russell D.
Published: August 2020

Gynura aurantiaca is a colorful foliage plant with velvety purple hairs that cover the green leaves and stems. However, its malodorous flowers and tendency towards a leggy appearance have been key limitations to its production and use for interiorscaping. This study was undertaken to determine if plant growth regulators could suppress its flowering and excessive growth, while improving its overall quality. A-Rest (ancymidol), B-Nine (daminozide), Bonzi (paclobutrazol), Cycocel (chlormequat chloride), and Florel (ethephon) were applied as foliar sprays in two applications in March at a two-week interval. Florel completely inhibited flowering but A-Rest, B-Nine, Bonzi, and Cycocel were ineffective in suppressing flowering. Florel-treated plants also produced more lateral shoots resulting in a compact and dense bush-like appearance, which improved and prolonged the aesthetic value of Gynura as a container-grown or hanging-basket interior plant. Whereas, plants treated by A-Rest, B-Nine, Bonzi, or Cycocel exhibited little improvement in their appearance compared to the control; some treatments were even detrimental. Regardless of application concentrations, subsequent growth of plants after pruning or rooting of cuttings was not affected by previous treatments of growth regulators.
Irrigating Landscape Bedding Plants and Cut Flowers With Recycled Nursery Runoff and Constructed Wetland Treated Water
Authors: Arnold Michael A. , Lesikar Bruce J. , McDonald Garry V. , Bryan Donita L. , Gross Amit
Published: August 2020

Direct nursery runoff (runoff), wetland treated recycled nursery runoff (recycled), and a municipal water source (tap) with and without elevated salt (NaCl targeted injection to 3.0 dS·m−1) levels were tested as potential drip irrigation sources for production of in-ground cut flower crops and landscape bedding plants. Two species of cut flowers, Helianthus annuus L. ‘Mammoth’ (sunflower) and Gladiolus hortulanus L. ‘Tout A Toi’ (gladiolus), and two bedding plants, Catharanthus roseus G. Don ‘Pacifica Red’ (vinca) and Zinnia elegans N.J. von Jacquin ‘Lilliput Mixed Colors’ (zinnia), were established in trial beds irrigated with the four water treatments during the summer of 2001 as a warm season experiment. A second experiment was conducted from November 2001 to May 2002 to investigate growth and flowering responses of two species of cut flower crops [Consolida ambigua (L.) P Ball & V Heywood (larkspur) and Narcissus tazetta L. ‘Galilea’ (paperwhite narcissus)] and two bedding plants [Antirrhinum majus L. ‘Montego Mix’ (snapdragons) and Viola × wittrockiana H. Gams ‘Crown Mix’ (pansies)]. Marketable crops of sunflower, paperwhite narcissus, and larkspur were produced with all four water treatments. Direct nursery runoff, recycled wetland treated water, and NaCl spiked water that were high in soluble salts during the heat of summer reduced yield and inflorescence diameter with sunflowers, but only slightly reduced inflorescence quality and had no effect on yield of paperwhite narcissus. These three treatments also affected stand density, but not yield of cut larkspur inflorescences in the cool season. Irrigation with water containing elevated NaCl levels reduced flower counts on pansies and growth indices on pansies and snapdragons over much of the growing season, but reduced snapdragon flowering only in spring. Vinca was unaffected by the irrigation treatments. Zinnia survival and flowering were reduced or delayed by irrigation with recycled or elevated NaCl water.
The Use of Suction Cup Lysimeters for Monitoring the Nutritional Status of Container Substrate for Optimum Growth of Willow Oak
Authors: Stanley Mary , Harris Roger , Scoggins Holly , Wright Robert
Published: August 2020

As container size and subsequent weight increase, extracting substrate solution for mineral nutrient analysis becomes difficult. Therefore, the objective of this research was to determine, using suction cup lysimeters (SCLs) to obtain the substrate solution, the electrical conductivity (EC) level associated with optimal growth of containerized willow oak (Quercus phellos L.). Two-year-old trees were grown in 56.8 liter (#15) containers and fertilized with either 0, 50, 100, 150, 200, 250, or 300 g (0, 1.8, 3.5, 5.3, 7.0, 8.8, or 10.5 oz) Osmocote Plus Northern 15N–3.9P–9.8K per container. Plant height and trunk diameter were measured at the beginning and end of the growing season. Leaf samples were taken at the conclusion of the study for mineral nutrient analysis. Growth was optimal at 200 g (7 oz) Osmocote per container and corresponded with a seasonal mean EC level of 0.5 dS/m. SCLs were an effective method of extracting solution for EC monitoring from large containers.
Seed Production and Germination of Eight Cultivars and the Wild Type of Ruellia tweediana: A Potentially Invasive Ornamental
Authors: Wilson Sandra B. , Mecca Laurie K.
Published: August 2020

Seed production and the influence of light and temperature on germination were determined for eight cultivars and the wild type form of Mexican petunia (Ruellia tweediana Griseb). The wild type form of R. tweediana has been ranked by the Florida Exotic Pest Plant Council as a Category I invasive plant, meaning it has invaded and is disrupting native plant communities in Florida. The cultivar ‘Purple Showers’ did not set any seed. Peak flowering and seed production for other cultivars generally occurred in August with ‘Morado Chi’, ‘Chi Chi’, and the wild type plants producing approximately three times the amount of seed produced by ‘Katie Pink’, ‘Katie Purple’, ‘Katie White’, and ‘Snow White’. For seed germination, significant cultivar x light interactions occurred for each temperature treatment. Some germination was observed at each temperature except for ‘Katie Purple’, ‘Katie Variegated’, and ‘Katie White’ at 33C (91.4F) without light. Regardless of cultivar or provision of light, 94-100% germination occurred at 30/20C (86/68F), with the exception of ‘Katie Purple’ (65%), ‘Katie Variegated’ (54%), and ‘Katie White’ (83%) without light. At 15, 24 or 33C (59, 75.2, and 91.4F), germination was generally greatest for ‘Chi Chi’ (with or without light) and ‘Morado Chi’ (with light). In parallel greenhouse studies, where seeds were germinated in pots containing a soilless medium, highest germination was achieved by ‘Chi Chi’, ‘Katie Pink’, ‘Katie Variegated’ and ‘Morado Chi’, while significantly lower germination was achieved by wild type plants (55%) by day 14. Storage studies demonstrated that germination of seed collected from the wild type and ‘Chi Chi’ plants began to decrease between 6 and 12 months when maintained at 24C (75.2F) but had equal (‘Chi Chi’) or higher (wild type) germination when maintained at 4C (39.2F) for 12 months.
Effects of Chilling Duration on Time to Shoot Emergence and Subsequent Growth of Hosta
Authors: Warr Jennifer , Keever Gary , Amling Jay , Findley Doug , Kessler Raymond
Published: August 2020

Eight hosta species or cultivars, Hosta plantaginea, H. ventricosa ‘Aureo Marginata’, H. ‘Tokudama’, H. ‘Francee’, H. ‘Sum and Substance’, H. ‘Fragrant Bouquet’, H. ‘Frances Williams’, and H. sieboldiana ‘Elegans’, were chilled in a walk-in cooler in two-week increments from 2 to 10 weeks at 4C (39F), prior to forcing in a heated greenhouse. More than 80% of all cultivars in all treatments emerged, except for H. ‘Tokudama’. For all cultivars tested, days to shoot emergence and days to first leaf unfurled decreased quadratically as chilling duration increased. Most rapid decreases occurred between 0 and 6 weeks of chilling. In the absence of chilling, H. plantaginea was the first cultivar to emerge, between 34 and 79 days before other cultivars. H. plantaginea was followed by H. ventricosa ‘Aureo Marginata’, H. ‘Sum and Substance’, and H. ‘Fragrant Bouquet’, all of which emerged before H. ‘Frances Williams’. Leaf area index, an indicator of plant vigor, increased linearly as chilling duration increased. Shoot dry weight increased in H. ‘Fragrant Bouquet’, H. ‘ Frances Williams’ and H. ‘Francee’, decreased slightly in H. plantaginea, and did not change in H. ventricosa ‘Aureo Marginata’, H. ‘Tokudama’, H. ‘Sum and Substance’, or H. sieboldiana ‘Elegans’ as chilling duration increased. This study indicates that there is no absolute chilling requirement for shoot emergence or subsequent growth of hosta tested. All cultivars benefited from chilling with quicker shoot emergence and fewer days to first leaf unfurled, with the greatest benefits occurring between 0 and 6 weeks. However, the benefits of chilling, as exemplified by growth and vigor, varied widely among species and cultivars.
Effect of Fertilizer Placement on Prostrate Spurge Growth in Container Production
Authors: Fain Glenn B. , Knight Patricia R. , Gilliam Charles H. , Olive John W.
Published: August 2020

Three experiments were conducted to evaluate the effect of fertilizer placement on prostrate spurge growth (Chamaesyce prostrata) in container production. In experiment one, Polyon 17N–2.TP–9.2K (17–5–11) was topdressed or dibbled at 45 g (1.6 oz) or 90 g (3.2 oz) per 11.3 liter (#3) container and either 90 g (3.2 oz) or 180 g (6.3 oz) per 26.3 liter (#7) container. In experiments two and three, 180 g (6.3 oz) of Polyon 17N–2.1P–9.2K (17–5–11) was topdressed or dibbled per 26.3 liter (#7) container. In all experiments 20 prostrate spurge seed were applied to the container surface 30 days after potting. In all experiments, weed count and weight were less in dibbled containers compared to topdressed. Across all experiments, weed shoot weights at or beyond 90 days after potting were from 31 to 888% greater in topdressed containers, compared to dibbled containers. Overall, dibbling fertilizer greatly reduced weed growth while producing no visible difference in ornamental plant growth.
Micropropagation of Virginia Sweetspire (Itea virginica ‘Henry's Garnet’)
Authors: Lindstrom Jon T. , Pelto Matthew C.
Published: August 2020

The woody shrub, Itea virginica L., Virginia sweetspire, has recently increased in popularity due to its multiple seasons of interest in the landscape. In this study, we investigated micropropagation as a means to produce this plant. Combinations of BA (1, 4, and 10 μM) and NAA (0.01, 0.1, and 1.0 μM) were evaluated for in vitro shoot induction in Itea virginica L. ‘Henry's Garnet’ on a Murashige and Skoog medium. The best combination of BA and NAA (4 μM and 0.1 μM) yielded an average of 7.9 microshoots per explant for ‘Henry's Garnet’. When dipped in a common auxin-containing, commercial rooting formulation, microshoots rooted ex vitro within four weeks. Tissue-culture produced plantlets of I. virginica ‘Henry's Garnet’ flowered one year after removal from culture.
Trifluralin (Preen) Dissipation from the Surface Layer of a Soilless Plant Growth Substrate
Authors: Judge Caren A. , Neal Joseph C. , Leidy Ross B.
Published: August 2020

Southeastern U.S. container nursery crop production relies upon frequent applications of preemergence herbicides for broad-spectrum weed control. An experiment was conducted to determine the length of residual control and the sensitivity of two grass species to Preen (trifluralin) applied to the surface of a pine bark:sand (7:1 by vol) potting substrate. The experiment was conducted twice at each of two locations during 2001. Samples of the potting substrate were taken 0, 1, 3, 7, 14, 28, 42 and 56 days after treatment (DAT) for laboratory analysis. Trifluralin was extracted from the potting substrate and quantified using gas chromatographic techniques. Large crabgrass and perennial ryegrass were seeded 0, 7, 14, 28, 42 and 56 DAT to bioassay for herbicide residues. Shoot and root length were measured two weeks after each seeding date. Preen residues in the surface of the potting substrate decreased rapidly after application and leveled off approximately 21 DAT. Based on the bioassay, March applications of Preen controlled large crabgrass and perennial ryegrass for 37 days or greater while May and June applications of Preen controlled the two species for only 3 to 21 days. These results suggest that trifluralin reapplication should be more frequent than the common interval of 56 to 70 days in the southeastern United States.
Florida Nursery Sales and Economic Impacts of 14 Potentially Invasive Landscape Plant Species
Authors: Wirth Ferdinand F. , Davis Kathy J. , Wilson Sandra B.
Published: August 2020

The Florida Nurserymen and Growers Association (FNGA) and the Florida Exotic Pest Plant Council (FLEPPC) recently asked nurserymen to stop production of 45 potentially invasive plant species that are relatively insignificant in the ornamental horticulture market. Controversies surround 14 additional species designated as invasive by the FLEPPC, but which are highly ornamental, widely used in landscaping, or have high economic value according to the FNGA. A mail survey of Florida ornamental nursery growers identified sales volume and value for each of these species. Economic output and employment impacts were calculated to determine the effect phasing-out these species may have on Florida's nursery industry. Total statewide sales of the 14 species were estimated at $45 million in 2001, with $34 million in-state and $11 million out-of-state. These sales translate into combined economic output impacts of $59 million and employment impacts of 800 jobs for Florida's economy, accounting for about 3% of total statewide output and employment impacts created by the ornamental nursery industry. These estimated impacts should not be interpreted as the expected industry loss from a phase-out of these species. If a species is not available for purchase, consumers will probably substitute alternative species, reducing the effect of any phase-out.
Survey of the Monitoring and Control Practices for Arthropod Pests by the Nursery Industry in Pennsylvania
Authors: Hoover Kelli , Sellmer James C. , Ostiguy Nancy
Published: August 2020

The effort to encourage the nursery industry to adopt IPM practices has met with varied success. In 2000, a survey was conducted to assess the monitoring and control practices for arthropod pests by the nursery industry in Pennsylvania, a state that ranks fourth in the nation in the number of certified nursery and greenhouse producers. Most respondents were the owner or partner of the operation and were responsible for the monitoring and pest management decisions for the firm. Most respondents reported that they identify the specific insect or mite when monitoring, but their ability to do this increased with their level of formal education. Most respondents did not keep permanent records of pest problems, although record keeping increased as total sales increased. Commonly reported cultural control practices included isolation of plants with pest problems for treatment, planting and selling plants hardy to the area, and selling resistant cultivars, although the use of these practices increased with more formal education. Over half of the respondents indicated that they often use cultural practices and select pesticides that conserve beneficial insects, yet 62% never release beneficials. Respondents that earned less than $50,000 in 1998 were least likely to spray whether pests were present or not or to characterize their use of chemical pesticides as ‘ often. ’ However, a majority of respondents reported that they ‘often’ use chemical pesticides (61 %) and ‘rarely’ or ‘never’ use less toxic alternatives such as horticultural oils, insecticidal soaps, or natural products, with some exceptions; 55% of landscape nurseries and 47% of garden centers reported often using oils and natural products, respectively. Although the nursery industry in Pennsylvania has adopted several cultural practices that are important components of IPM, results from the survey indicate that demonstrations of and education about the use, cost-benefits, and efficacy of less toxic alternatives to chemical pesticides and release of beneficials for the control of insects and mites are needed to convince the nursery industry to increase their adoption of these IPM tactics.
Auxin Application to Stem Cuttings of Selected Woody Landscape Plants by Incorporation Into a Stabilized Organic Rooting Substrate
Authors: Blythe Eugene K. , Sibley Jeff L. , Tilt Ken M. , Ruter John M.
Published: August 2020

Stem cuttings of Buxus sinica var. insularis ‘Wintergreen’, Elaeagnus x ebbingei, Ficus benjamina, Gardenia augusta ‘Radicans’, Ilex glabra ‘Nigra’, Ilex vomitoria ‘Nana’, Juniperus conferta ‘Blue Pacific’, Ternstroemia gymnanthera, and Trachelospermum asiaticum were inserted into a stabilized organic rooting substrate (plugs comprised of peat and a polymer binder) that had been soaked in water, aqueous solutions of K-IBA (15 to 75 ppm), or K-IBA + K-NAA (15 ppm + 7.5 ppm to 60 ppm + 30 ppm). Rooting and initial shoot growth responses were compared with cuttings receiving a basal quick-dip in K-IBA (1000 ppm) or K-IBA + K-NAA (1000 ppm + 500 ppm). Rooting percentage, number of roots per rooted cutting, and total root length per rooted cutting for cuttings rooted in auxin-treated plugs were similar to or greater than cuttings receiving a basal quick-dip; lesser results were obtained in a few cases with K-IBA + K-NAA. Percent of rooted cuttings with new shoots and shoot length per rooted cutting for cuttings rooted in plugs treated with K-IBA were mostly similar to cuttings receiving a basal quick-dip in K-IBA, while cuttings rooted in plugs treated with K-IBA + K-NAA exhibited similar or lesser results compared to cuttings receiving a basal quick-dip in K-IBA + K-NAA.
BA-Induced Shoot Formation in Indian Hawthorn
Authors: Oates Jayme M. , Keever Gary J. , Kessler J. Raymond
Published: August 2020

A study was conducted to determine effects of multiple weekly applications of different concentrations of a synthetic cytokinin, benzyladenine (BA), on two Indian hawthorn [Rhaphiolepis Lindl. Cor. Poir. indica (L.) Lindl. (Crataegus indica L.)] cultivars, ‘Olivia’ and ‘Eleanor Taber’. In a greenhouse in winter 2000-2001, ‘Olivia’ Indian hawthorn received four weekly applications of 2500 ppm or 5000 ppm BA. At 45 days after last treatment (DALT) untreated plants had formed no new shoots, while plants treated with 2500 and 5000 ppm BA produced 6.8 and 5.4 new shoots, respectively. New leaves of plants treated with 5000 ppm BA were abnormally mottled, twisted, and cupped. In an outdoor nursery in summer 2001, ‘Olivia’ in 3.8 liter (#1) and 26.5 liter (#7) containers received three and two applications, respectively, at concentrations from 0 to 5000 ppm. Untreated plants in 26.5 liter (#7) containers formed 4.7 new shoots at 30 days after initial treatment (DAIT), and new shoots increased from 83 with 1250 ppm BA to 126 with 5000 ppm BA. Plants in 26.5 liter (#7) containers were retreated in September, at which time shoots were inactive. At 30 DAIT controls averaged less than one new shoot per plant, while plants averaged 18 new shoots when treated with 1250 ppm BA and 105 new shoots when treated with 5000 ppm BA. In spring 2002, plants in 3.8 liter (#1) containers were retreated following the same protocol as in 2001, in conjunction with a new set of ‘Olivia’ and the Indian hawthorn cultivar, ‘Eleanor Taber’. At 30 DALT new shoot formation increased three fold in ‘Olivia’ and five fold in ‘Eleanor Taber’ after three applications of up to 5000 ppm BA. Injury increased with increasing BA rates in ‘Olivia’ at 30 DALT, with leaf cupping and discoloration apparent on plants treated with concentrations above 1250 ppm. No injury was observed in ‘Eleanor Taber’. By 90 DALT new shoots had matured normally and exhibited minimal phytotoxic symptoms.
Response of Hosta to BA Crown Drenches Applied at Division and Establishment
Authors: Warr Jennifer C. , Keever Gary J.
Published: August 2020

New offset formation in hosta in response to benzyladenine (BA) drenches applied at division and establishment was examined. Hosta Tratt. ‘Frances Williams’ and H. ‘Francee’ were separated into uniform single-bud divisions and drenched with 50 ml of 0, 100, 500, 1000, 2000 or 3000 ppm (mg/liter) BA just prior to potting (division) or two weeks later when substrate-container interface root development was evident (establishment). A 3000 ppm (mg/liter) foliar spray applied to established plants served as a standard. Offsets were counted in plants treated at division 14 days later at which time BA was applied to established plants. Offsets were counted on all plants 30 and 60 days after BA was applied to established plants and in spring of the following year. Offset counts increased rapidly in both cultivars following drench applications of increasing BA concentrations, whether applied at division or establishment. This positive response to increasing BA drench concentrations was evident 60 days after treatment (DAT) and the following spring, except in H. ‘Frances Williams’ drenched at division. However, benefits of either BA method or time of application were less pronounced in spring, following a period of dormancy.
Kosteletzkya virginica Can be Rooted from Leafy or Leafless Stem Cuttings
Authors: Haynes Cynthia L. , Graves William R.
Published: August 2020

Protocols for producing Virginia mallow [Kosteletzkya virginica (L.) K. Presl. ex A. Gray] are needed to allow growers to meet the emerging demand for this herbaceous perennial. Virginia mallow has been propagated from seeds and by division, but the potential for using stem cuttings has not been evaluated. Two experiments were conducted to determine how indolebutyric acid (IBA) treatment affects rooting percentage and the number and length of primary roots on stem cuttings taken from different positions on stock plants. Rooting percentage was similar (mean = 68%) among single-leaf cuttings from nonterminal, distal positions on stock plants and leafless cuttings from basal positions. Averaged over these nonterminal cutting types, IBA treatment more than doubled rooting percentage, root count, and the length of the longest root. Terminal cuttings with leaves rooted more successfully (83%) than subtending cuttings with leaves during a second experiment, and IBA effects were less pronounced than during the first experiment. Results demonstrate that stem cuttings with or without leaves can be used to propagate Virginia mallow efficiently. Application of IBA is not necessary but enhances rooting and appears most beneficial for leafless cuttings.
Water Loss Estimates for Five Recently Transplanted Landscape Tree Species in a Semi-Arid Climate
Authors: Montague Thayne , Kjelgren Roger , Allen Rick , Wester David
Published: August 2020

Over three growing seasons (1994–1996), water loss of five recently transplanted, balled and burlaped (B&B) tree species was investigated using below-ground, electronic weighing lysimeters. For each species, actual tree water loss was correlated with reference evapotranspiration (ETO) to create a water loss multiplier. At the beginning of each growing season a single tree was planted into each lysimeter. Selected species were: London planetree (Platanus x acerifolia ‘Bloodgood’), corkscrew willow (Salix matsudana ‘Tortuosa’), littleleaf linden (Tilia cordata ‘Greenspire’), Norway maple (Acerplatanoides ‘Emerald Queen’), and green ash (Fraxinuspennsylvanica ‘Patmore’). Throughout each growing season, trees were well-watered and lysimeter mass and meteorological variables were collected on site. Water loss multipliers for each tree species were calculated as the ratio of water loss (based upon total leaf area) to total daily ETO. Results indicate corkscrew willow and littleleaf linden had the greatest daily mean water loss (5.6 and 4.8 mm, respectively) (0.22 and 0.18 in, respectively), while Norway maple had the least (1.1 mm) (0.04 in). Water loss multipliers were greatest for corkscrew willow and littleleaf linden (1.1 and 0.9, respectively) and least for Norway maple (0.2). Regression analysis indicated total daily ETO had limited influence on total daily tree water loss. This suggests factors other than ETO influence water loss of recently transplanted, B&B trees in a semi-arid climate.
Selective Control of Bentgrass in ‘True Putt’ Creeping Bluegrass
Authors: Carson T.D. , Horgan B.P. , White D.B.
Published: August 2020

The ability to selectively control a specific cool-season grass growing in a mixed stand would offer great advantages to turfgrass managers. It is common for monostands of creeping bentgrass (Agrostis stolonifera) to become infested with annual bluegrass (Poa annua). Conversely, monostands of ‘True Putt’ creeping bluegrass (Poa annua var. reptans), a commercially available perennial biotype of Poa annua, often develop bentgrass infestations. The objective of this study was to evaluate the efficacy of various herbicides for the selective control of bentgrass with minimal injury to True Putt. Nine herbicide treatments were applied to 248 cm2 (38.4 in2) plugs maintained at 1.3 cm (0.51 in) in the greenhouse. The experiment was conducted twice during the winter of 2001–2002. Several ratings were made over the four week period on quality of bentgrass and creeping bluegrass and on reduction of bentgrass cover. Vantage, Image, Assure II, Fusilade II, Finale, and Balance Pro gave a minimum of 65% control with Vantage, Assure II, Fusilade II, and Finale achieving 100% control. However, Vantage was the only herbicide that provided complete control of bentgrass while causing no significant reduction in the quality of True Putt creeping bluegrass. Assure II and Fusilade II also provided complete control of bentgrass, but both had a negative impact on the quality of True Putt.
Effect of Storage Temperature and Seed Moisture on Germination of Stored Flowering Dogwood Seed
Authors: Reed Sandra M.
Published: August 2020

Dogwood producers occasionally face a shortage of flowering dogwood seed. Storing excess seed during years when seed are abundant would allow growers to stabilize their seed supply. This study was conducted to evaluate the effects of seed moisture and storage temperature on the viability of stored flowering dogwood seed. Seed were collected in Fall 1999 and 2000, dried to 6, 10 and 14% moisture content, and stored at 22, 5 and −20C (72, 41 and −4F) for 1, 2 and 3 years. Following storage, seed were cold stratified and sown in a greenhouse. Percent germination and seedling dry weight were recorded. Seed stored at 22C (72F) quickly lost viability. At 5C (41F), seed moisture content was critical, with seed dried to 14% moisture content germinating poorly after 2 years and failing to germinate after 3 years in storage. In general, storage at −20C (−4F) was superior to storage at 5C (41F). Seed moisture content was not as critical at −20C (−4F) as it was at 5C (41F), but may become more important if length of storage is extended past 3 years. Based on the results of this study, it is recommended that seed be dried to 6 to 10% moisture prior to storage, stored in air-tight containers, and stored in a −20C (−4F) freezer.
Evaluation of Clones, Container Types and Tissue Culture Media for Production of Calla Lilies as a Nursery Crop
Authors: Pounders Cecil , Nyochembeng Leopold
Published: August 2020

Studies were designed to determine if colored callas (Zantedeschia sp.) can be successfully grown as a spring color crop under field conditions in the Southeastern United States without substantial modification of greenhouse culture protocols and if yield of clean stock from tissue culture can be improved. Results indicate colored calla lily production in containers in hardiness Zone 8B can be successful, without making significant modifications to either existing greenhouse production guidelines or the environment used for woody plant container culture. Neither fiber nor deeper containers improved overall calla performance over traditional plastic pots. ‘Garnet Glow’ and ‘Pink Persuasion’ produced the most blooms over 6 weeks of evaluation and would be better adapted for the spring color market than ‘Florex Gold’ or ‘Mango’ which bloomed heavily for only two weeks. The disease index developed for this study indicated ‘Mango’, ‘Florex Gold’, ‘Rubylite Pink Ice’ and ‘Majestic Red’ suffered the most soft rot damage while ‘Pink Persuasion’, ‘Garnet Glow’ and ‘Pot of Gold’ had the least when using field grown tubers. Tissue culture propagation efficiency was improved, as reflected in propagule size, by increasing sucrose levels in production media from 30 g/liter up to 120 g/liter, thus speeding production of larger clean microtubers. Proper cultivar selection and strict adherence to a disease control program, as in greenhouse production, allow production of high-quality colored callas in the Gulf South as an outside container crop for the spring color market.
Effects of Mycorrhizal Fungi, Biostimulants and Water Absorbing Polymers on the Growth and Survival of Four Landscape Plant Species
Authors: Abbey Tim , Rathier Tom
Published: August 2020

The addition of commercial mycorrhizal, transplant gel and/or biostimulant products to the root balls or backfill soil of Japanese holly, (Ilex crenata Thunb. ‘Green Luster’); arborvitae, (Thuja occidentalis L. ‘Emerald Green’); Japanese spirea, (Spiraea japonica L.f. ‘Shibori’); Bradford Callery pear, (Pyrus calleryana Decne. ‘Cleveland Select’ and ‘Redspire’) at the time of planting did not lead to significant improvement of plant growth or transplant survival compared to untreated plants receiving routine mulching with pine bark mulch alone.
Effect of Bioplex™ on Transplant Success and Recovery of Summer-dug Goldenraintree
Authors: Sammons Jonathan D. , Struve Daniel K.
Published: August 2020

Biostimulants are intended to reduce stress associated with non-dormant (summer-dug) harvest of field-grown nursery stock; however, the effectiveness of biostimulant treatment is uncertain. We tested the effects of three application methods of Bioplex™ (a biostimulant) on transpiration rates, transplant survival, and recovery of field-grown goldenraintree (Koelrueteria paniculata Laxm.), which is considered difficult to transplant and is rarely summer dug. Bioplex™ was applied as a foliar spray, soil drench, or a combination of foliar spray and soil drench. Bioplex™ reduced transpiration rates of trees by 12% compared to untreated control trees. Root loss associated with digging reduced transpiration rates and had a greater effect on transpiration than any Bioplex™ treatment. Survival 12 months after transplanting was 100%. Bioplex™ treatments applied before digging had no effect on growth after transplanting. Transplanted trees had reduced caliper growth and shoot extension the season after transplant compared to non-dug controls. Although Bioplex™ reduced transpiration rates for three to five days after application in non-dug trees, there were no long-term benefits to survival or re-growth to summer transplanted trees.
Influence of Selected Fungicides on in vitro Growth of Artillery Fungi (Sphaerobolus spp.)
Authors: Geml József , Davis Donald D. , Geiser David M.
Published: August 2020

We tested the inhibitory effect of 14 fungicides, 13 of which were known to be effective against the basidiomycete Agaricus, at 5 and 20 ppm on the in vitro growth of three species of artillery fungi: Sphaerobolus iowensis, S. stellatus, and a previously undescribed Sphaerobolus sp. Captafol, epoxiconazole, thiophanate-methyl, triflumizole, and triphenyltin acetate were the most effective inhibitors against all three Sphaerobolus species, and the reduction in growth was directly related to fungicide concentration. Chloroneb, chlorothalonil/zinc oxide, fuberidazole, glyodin, and tolylfluanid showed varying results, depending on fungal species and fungicide concentration; however, they were much less effective than the previous five fungicides. Dazomet, dinocap, folpet, and ferbam failed to slow the growth of any artillery fungi at either concentration. This preliminary study revealed that certain fungicides suppress growth of artillery fungi and should be further tested in the field.
Effectiveness of Commercial Mycorrhizal Inoculants on the Growth of Liquidambar styraciflua in Plant Nursery Conditions
Authors: Corkidi Lea , Allen Edith B. , Merhaut Don , Allen Michael F. , Downer James , Bohn Jeff , Evans Mike
Published: August 2020

The effectiveness of several commercial mycorrhizal inoculants on the growth and development of Liquidambar styraciflua (sweetgum) was evaluated. Plants were grown in a nursery potting mix and were inoculated with the mycorrhizal products at the manufacturer's recommended rate. The growth response of mycorrhizal and nonmycorrhizal plants was analyzed at two harvests (8 and 14 weeks after transplanting). Significant differences were found in the growth of L. styraciflua to mycorrhizal colonization with the different commercial products. Fourteen weeks after transplanting, inoculation with products 1 (Earth Roots), 2 (MycoApply endo), and 3 (VAM 80) enhanced the growth of sweetgum relative to the nonmycorrhizal plants. However, plants inoculated with products 2 and 3 had greater leaf area, dry mass and relative growth rates than those inoculated with product 1. Plants of L. styraciflua inoculated with product 4 were less responsive to mycorrhizal colonization and only increased their leaf area relative to the non-inoculated controls. Testing both the infectivity and effectiveness of mycorrhizal fungi is recommended for the successful application of mycorrhizal technology in horticultural practices.
Root Growth of Three Horticultural Crops Grown in Pine Bark Amended Cotton Gin Compost
Authors: Jackson Brian E. , Wright Amy N. , Sibley Jeff L. , Kemble Joseph M.
Published: August 2020

In the southeastern United States, inconsistent pine bark (PB) supplies and overabundance of cotton gin by products warrant investigation about the feasibility of replacing PB with cotton gin compost (CGC) for container horticultural plant production. Most research on the use of composted organic substrates for horticultural plant production has focused on shoot growth responses, so there is a need to document the effect of these substrates on root growth. In 2004 ‘Blitz’ tomato (Lycopersicon esculentum L.), ‘Hot Country’ lantana (Lantana camara Mill. ‘Hot Country’), and weeping fig (Ficus benjamina L.) were placed in Horhizotrons™ to evaluate root growth in 100% PB and three PB:CGC substrates containing by volume, 60:40 PB:CGC, 40:60 PB:CGC, and 0:100 PB:CGC. Horhizotrons™ were placed in a greenhouse, and root growth in all substrates was measured for each cultivar. Physical properties (total porosity, water holding capacity, air space, and bulk density) and chemical properties (electrical conductivity and pH) were determined for all substrates. Physical properties of 100% PB were within recommended guidelines and were either within or above recommended ranges for all PB:CGC substrate blends. Chemical properties of all substrates were within or above recommended guidelines. Root growth of all species in substrates containing CGC was similar to or more enhanced than root growth in 100% PB.
Effects of Salinity and Freezing on Acer platanoides, Tilia cordata, and Viburnum lantana
Authors: Zimmerman E.M. , Jull L.G. , Shirazi A.M.
Published: August 2020

The purpose of this study was to evaluate the effects of NaCl and freezing temperatures on dormant lateral buds of Acer platanoides L. (Norway maple), Tilia cordata Mill. (littleleaf linden), and Viburnum lantana L. (wayfaringtree viburnum). The role of bud morphology was also examined. Buds were exposed to three NaCl concentrations [0, 2000, or 16,000 mg/liter (0, 2000, 16,000 ppm)] and eleven freezing temperatures [4, −4, −8, −12, −16, −20, −24, −28, −32, −36, and −40C (39, 25, 18, 10, 3, −4, −11, −18, −26, −33, −40F)] in November 2001 and January and March 2002. Electrolyte leakage and visual ratings of outer and inner bud tissue browning were used to assess injury. Bud injury generally increased as NaCl concentrations increased and temperatures decreased. Buds exposed to NaCl and freezing temperatures had greater electrolyte leakage than buds exposed to freezing temperatures alone. Norway maple buds had the highest electrolyte leakage, followed by wayfaringtree viburnum, and littleleaf linden in response to freezing temperatures and NaCl. The naked buds of viburnum had significantly more inner tissue browning than the scaled buds of maple and linden in response to freezing temperatures and NaCl in January 2002. Wayfaringtree viburnum exhibited increased tissue injury in response to NaCl and low temperature treatments in March 2002.
Evaluation of Insecticides for Suppression of Japanese Beetle, Popillia japonica Newman, and Crapemyrtle Aphid, Tinocallis kahawaluokalani Kirkaldy
Authors: Pettis Gretchen V. , Braman S. Kristine , Guillebeau L. Paul , Sparks Beverly
Published: August 2020

Crapemyrtle aphid, Tinocallis kahawaluokalani (Kirkaldy), and Japanese beetle, Popillia japonica Newman, cause extensive damage to crapemyrtle, Lagerstroemia spp., in both the landscape and the nursery. We evaluated foliar and systemic insecticides for control of these two important pests in a field trial. Aphid control was also evaluated in a separate screen house trial on five cultivars of crapemyrtle. Talstar GH (bifenthrin), Scimitar GC (lambda-cyhalothrin), Merit 75WP (imidacloprid) and Flagship (thiamethoxam) were among the most effective of eleven insecticides tested in the field trial for suppression of concurrent populations of aphids and beetles. Greatest reduction in Japanese beetle damage alone was evident with bifenthrin and lambda-cyhalothrin. Aphid numbers were lowest on plants treated with Orthene TTO (acephate), Merit 75 WP and Flagship in the field trial and Flagship, Talstar GH and Scimitar GC in the screen house trial. Aphid numbers, among the five cultivars included in the screen house evaluations, were highest on ‘Hopi’ and lowest on ‘Acoma’.
Fertilizer Applications on Establishment and Growth of Three Groundcover Species in Sun and Shade
Authors: Stafne R.A. , Einert A.E. , Klingaman G.L.
Published: August 2020

Use of groundcovers in the landscape is often limited by slow establishment when compared to turf. Hedera helix L. (English ivy), Euonymus fortunei ‘Coloratus’ (Turcz.) Hand.-Mazz. (purpleleaf wintercreeper euonymus) and Liriope spicata Lour. (creeping lily-turf) were evaluated in full sun and 60% shade to determine the effects of fertilizer applications on establishment and growth. Limited fertilizer × species interaction was detected, which may have been due, in part, to the soil incorporation of mushroom compost. Establishment and survivability of Hedera in full sun may have been influenced by lack of acclimation from shade to sun. There was no significant difference in establishment rates between Liriope and Euonymus; however, under shade Euonymus did not develop its characteristic fall color. Hedera was established in one season under 60% shade and, of these three species, can be considered the most competitive with turf under similar conditions for low traffic areas of the landscape.
NAA Reduces Vegetative Shoot Growth on Rootstocks of Ornamental Peach
Authors: Fare Donna C. , Keever Gary J. , Halcomb Mark
Published: August 2020

Vegetative bud growth was controlled on dormant peach rootstock of budded Prunus persica (L.) Batsch. ‘Bon Fire’ with naphthaleneacetic acid (NAA) applied as a trunk paint. Vegetative bud growth was suppressed with all test concentrations (2,875 to 11,500 ppm) through 210 days after treatment (DAT), although scion bud mortality of ‘Bon Fire’ was greater with concentrations above 8,625 ppm. Naphthaleneacetic acid applied at 5,750 ppm provided excellent vegetative bud control, vigorous scion bud growth, and minimal scion bud mortality.
Evaluation of Treated Effluent as an Irrigation Source for Landscape Plants
Authors: Fox Laurie J. , Grose J. Norman , Appleton Bonnie L. , Donohue Stephen J.
Published: August 2020

Treated effluent from the Hampton Roads Sanitation District (HRSD) Virginia Initiative Plant (VIP) was evaluated in 2000 and 2001 as an irrigation source for landscape plants. Landscape plants common to eastern Virginia were installed in raised beds and overhead irrigated at the rate of 2.5 cm (1 in) per week for five months. Aesthetic quality ratings, and soil and water analyses, were conducted monthly. Aesthetic quality ratings were lower on certain plants irrigated with treated effluent in both years of the study. Damage appeared to result from foliar contact by irrigation water high in dissolved salts. Soil tests showed salt accumulation in the planting soil. Damage that occurred on plants irrigated with treated effluent was species specific and included leaf burn, chlorosis, defoliation, stunting, and death. All symptoms were consistent with and typical of salt damage. Salt concentrations in this treated effluent were too high to allow use of this water as an overhead irrigation source for many landscape plants without further treatment or dilution. Irrigation with treated effluent should be based on landscape species composition, local climate conditions, and irrigation method.