bluuebunny/crossref_metadata_2025 huggingface dataset:
BA Application Timing Affects Offset Formation in Hosta
Authors: Schultz Heather C. , Keever Gary J. , Raymond Kessler J. , Dute Roland R.
Published: August 2020

A study was conducted to determine the effects of timing of benzyladenine (BA) application following division and potting of hosta on offset formation as a means of accelerating propagation. Stock plants of two cultivars, ‘Francee’ and ‘Frances Williams’, were divided and potted. Plants received a single foliar spray application of 3000 ppm BA immediately after potting (0) or 1, 2, 3, 4, 5, or 6 weeks after potting. BA stimulated the outgrowth of axillary and rhizomic buds in both cultivars, but in most cases, only for plants in which BA application was delayed 3 or more weeks after potting. Compared to the non-treated control, plants treated with BA 3 or more weeks after potting produced more offsets; however, plants treated 0, 1, or 2 weeks after potting produced similar numbers of offsets as the control. Offsets on plants treated with BA formed more leaves than offsets on non-treated control plants, but application timing did not affect leaf number. ‘Francee’ produced offsets with more leaves than offsets of ‘Frances Williams’. Neither application timing nor BA affected growth index.
Survey of Best Management Practices in Container Production Nurseries
Authors: Fain Glenn B. , Gilliam Charles H. , Tilt Ken M. , Olive John W. , Wallace Beth
Published: August 2020

Twenty-four nurseries producing container-grown plants were surveyed along the coastal zone of south Alabama to determine Best Management Practices (BMPs) implemented since 1988. All nurseries utilized multiple BMPs. Seventy-five percent of all nurseries surveyed have the capability to capture runoff water; however, larger nurseries (medium 4.5–16.6 ha (11–40 A); large 16.6+ ha (40+A)) were more likely to capture runoff than smaller nurseries 0.4–4.1 ha (1–10 A). Since 1988, 78% of all collection ponds have been built with 44% of those being built in the past 5 years. Other BMPs widely used included installation of grass filter/erosion strips, having specific personnel devoted to water management, use of control release fertilizers, scouting for pests, use of horticultural oils, and staggered herbicide applications.
Responses of Six Wildflower Species to Seed Matric Priming
Authors: Pill Wallace G. , Bender Renee H. , Pie Adrienne C. , Marvel Josh K. , Veacock Erin E.
Published: August 2020

Seeds of six wildflower species [Aster novae-angliae (New England aster), Rudbeckia hirta (Black-eyed Susan), Liatris spicata (Blazing star), Hesperis natronalis (Dame's rocket), Gaillardia aristata (Perennial gaillardia), and Asclepias tuberosa (Butterfly weed)] were matrically primed in fine, exfoliated vermiculite. Seeds were primed for 7 days at 15C (59F) at an initial matric potential of−0.5 MPa (−5 bars) in darkness, then dried for 7 days before sowing. A seed: vermiculite (1:2 by wt) ratio was found to be the most appropriate of several ratios because it increased germination rate of all species except Black-eyed Susan, increased the germination percentage of Perennial gaillardia, and prevented germination of Dame's rocket and Perennial gaillardia during priming. Under restricted water availability [−0.25 and−0.50 MPa (−2.5 and−5.0 bars)] priming increased the germination percentage of Perennial gaillardia and Butterfly weed and increased the germination rate of all species. In a glasshouse study, priming increased the emergence percentage of Perennial gaillardia and increased the emergence rate of all species. Compared with hydration of the vermiculite with water, using 10−3 M gibberellic acid during priming increased the emergence rate of Dame's rocket, increased the emergence percentage of Perennial gaillardia, and increased the shoot dry weights of New England aster and Black-eyed Susan.
Cutting Propagation and Container Production of ‘Flora Sun’ Beach Sunflower
Authors: Norcini Jeffrey G. , Aldrich James H.
Published: August 2020

Helianthus debilis Nutt. ssp. debilis ‘Flora Sun’, ‘Flora Sun’ beach sunflower, is a native, herbaceous perennial that should be propagated by cuttings to maintain its genetic and phenotypic fidelity. Stem cuttings were treated with a quick dip of a potassium salt of 1H-indole-3-butyric acid (K-IBA) solution at 0, 250, 500, 1000, 1500, 2000, 2500, or 3000 mg/liter (ppm) and rooted under intermittent mist. The root systems of six of twelve cuttings were harvested 17 and 21 days after treatment. The remaining six cuttings were transplanted in a soilless substrate to determine the effects of K-IBA on establishment in containers. Treatment of stem cuttings with K-IBA increased the number of roots and root fresh weight when cuttings were rooted under summer greenhouse conditions, but K-IBA did not provide any substantial short-term benefits in survival or growth of rooted cuttings after they were transplanted into plastic containers.
Banker Plants: Evaluation of Release Strategies for Predatory Mites
Authors: Pratt P.D. , Croft B.A.
Published: August 2020

Spider mites (Tetranychidae) are among the most injurious pests of commercial landscape plant nurseries. The introduction of predaceous mites (Phytoseiidae) into nursery crops for control of spider mites can be an effective alternative to pesticides. We sought to evaluate the use of banker plants as a method of rearing and dispersing predatory mites for the control of spider mites in landscape nursery systems. Banker plants include any plant addition that aids in development and dispersal of predators for control of herbivorous pests. Addition of the predatory mite Neoseiulus fallacis (Garman) into spider mite infested arborvitae and rhododendron banker plants held in replicated greenhouse cubicles resulted in more predatory mites dispersing to spider mite infested plants downwind than were originally inoculated. To improve persistence and subsequent dispersal of predatory mites in an arborvitae banker plant, we evaluated the use of adding supplemental prey (spider mites) and applying a portion of the plant foliage with a pyrethroid to provide a refuge for the prey. Reintroduction of prey increased the dispersal duration of N. fallacis but the pyrethroid-based refuge did not. Predatory mites dispersing from arborvitae banker plants of approximately 1.25 m (4.1 ft) tall were collected from receiver plants at 10, 20 and 30 m (10.9, 21.9 and 32.8 yd) down wind. Integration of a banker plant system into a landscape nursery operation is discussed.
Biological Control of the Artillery Fungus, Sphaerobolus stellatus, with Trichoderma harzianum and Bacillus subtilis
Authors: Brantley Elizabeth A. , Davis Donald D. , Kuhns Larry J.
Published: August 2020

Three strains of the fungus Trichoderma harzianum Rifai and two strains of the bacterium Bacillus subtilis (Ehrenberg) Cohn were evaluated for their ability to suppress colonization and sporulation of the artillery fungus (Sphaerobolus stellatus Tode:Pers.) on oatmeal agar. All five biological control agents inhibited growth of S. stellatus, but efficacy depended on time of application. Simultaneous inoculation of agar with S. stellatus and the biocontrol agents, as well as inoculation of biocontrol agents 14 days prior to S. stellatus, resulted in complete inhibition of S. stellatus. Inoculation of agar with biocontrol agents 14 days after inoculation with S. stellatus reduced, but did not completely suppress S. stellatus colonization and sporulation. In this experiment, gleba (spore masses) treated with all strains of T. harzianum and strain GBO3 of B. subtilis did not germinate, but 13% of gleba treated with strain MBI 600 of B. subtilis did germinate. Trichoderma harzianum was more effective than B. subtilis as a biocontrol agent.
Growth Regulation of Russian Sage During Greenhouse and Nursery Production
Authors: Burnett S.E. , Keever G.J. , Gilliam C.H. , Kessler J.R.
Published: August 2020

Growth response of Perovskia atriplicifolia (Russian sage) treated with several plant growth retardants (PGRs) was determined under three production regimes: 1) small plants in 10 cm (4 in) pots grown in a greenhouse and half transplanted into the landscape at 6 weeks after treatment (WAT), and 2) large plants grown in 3.8 liter (#1) pots in a greenhouse or 3) in an outdoor nursery. Plants in 3.8 liter (#1) pots were not transplanted into the landscape. Treatments included Cutless at 50, 100 and 150 ppm; Sumagic at 20, 40 and 60 ppm; B-Nine/Cycocel tank mixes at 2,500/1,500, 5,000/1,500 and 7,500/1,500 ppm; Pistill at 500 and 1,000 ppm; and a non-treated control. All PGRs controlled plant growth through 6 WAT in the greenhouse and 2 weeks after planting. At this time (8 WAT), plants treated with the most effective rate of Cutless (150 ppm), Sumagic (20, 40, or 60 ppm), B-Nine/Cycocel tank mixes (5,000 ppm/1,500 ppm), and Pistill (500 or 1,000 ppm) were 32%, 32%, 25%, and 32% smaller in 10 cm (4 in) pots and 21%, 22%, 22%, and 16% smaller in 3.8 liter (#1) pots, respectively, compared to non-treated controls. Treatment effects were non-significant by 4 weeks after plants grown in the greenhouse in 10 cm (4 in) pots for 6 weeks were transplanted into the landscape (10 WAT). Plants in 3.8 liter (#1) pots in the greenhouse were significantly smaller, excluding those treated with Pistill, than non-treated controls at 12 WAT; at this time, the most effective rate of Cutless (150 ppm), Sumagic (40 ppm), and B-Nine/Cycocel tank mixes (5,000 ppm/1,500 ppm) suppressed growth 21%, 23%, and 26%, respectively. For 3.8 liter (#1) pots in the nursery, Cutless suppressed growth 5–11% at 2 WAT only, and the most effective rate of Sumagic (60 ppm) reduced growth 7% at 4 WAT, but not thereafter. The most effective rates of B-Nine/Cycocel (7,500 ppm/1,500 ppm) and Pistill (1,000 ppm) suppressed growth 13% and 10%, respectively, at 8 WAT. Results suggest that PGR effectiveness is less outdoors under nursery conditions than in the greenhouse, particularly for Cutless and Sumagic. The duration and magnitude of B-Nine/Cycocel treatment effects suggest that this PGR combination may provide the most effective growth control of Russian sage under nursery conditions.
Susceptibility of Ilex Species, Hybrids and Cultivars to Florida Wax Scale (Ceroplastes floridensis Comstock)
Authors: Hodges Greg , Ruter John M. , Kristine Braman S.
Published: August 2020

Susceptibility of 231 holly species, hybrids and cultivars to Florida wax scale (Ceroplastes floridensis Comstock) were evaluated on field grown plants in Tifton, Georgia. Florida wax scale have two generations/year in this region. Population ratings on different parental lines were grouped as either low populations (<10 scales/60 second count), moderate populations (11–20 scales/60 second count), high populations (21–40 scales/60 second count) and very high populations (>40 scales/60 second count). Taxa from the study rated as being least preferred (low populations) by the Florida wax scale included those with I. crenata, I. buergeri, I. glabra, I. myrtifolia, I. verticillata and I. vomitoria within parental lines. Those prone to heavy infestations were I. aquifolium, I. × attenuata, I. cassine, I. ciliospinosa, I. cornuta, I. × koehneana, I. latifolia, I. × meserveae, I. opaca, I. purpurea, I. rugosa and I. serrata. Other scale insects noted on the hollies included: Barnacle wax scale (Ceroplastes cirripediformis Comstock), Indian wax scale (Ceroplastes ceriferus (Fabricius)), European fruit lecanium (Parthenolecanium corni Bouche), Brown soft scale (Coccus hesperidum Linneaus), Tea scale (Fiornia theae Green), Latania scale (Hemiberlesia lataniae (Sign.)), and a pit scale (Asterolecanium puteanum Russell).
Resistance of Boxwood Varieties to the Boxwood Leafminer, Monarthropalpus flavus (Schrank)
Authors: d'Eustachio Gabriel , Raupp Michael
Published: August 2020

A survey of nine cultivars of Buxus at the United States National Arboretum revealed significant differences in levels of infestation by the boxwood leafminer, Monarthropalpus flavus (Schrank). An analysis of larval survival confirmed high levels of susceptibility in Buxus sempervirens ‘Myrtifolia’ and Buxus microphylla ‘National’ while B. sempervirens ‘Handsworthiensis’ and B. sempervirens ‘Vardar Valley’ exhibited high levels of resistance. Other varieties exhibited intermediate levels of resistance. Field surveys and laboratorystudies indicated that female flies deposited eggs in all cultivars even highly resistant ones. This lack of preference suggests that the mechanism of resistance is antibiosis or phenological asynchrony rather than antixenosis.
Evaluation of Biological and Chemical Control Methods for Black Vine Weevil, Otiorhynchus sulcatus (Fabricius) (Coleoptera: Curculionidae), in Container Grown Perennials
Authors: Gill Stanton , Lutz Joanne , Shrewsbury Paula , Raupp Michael
Published: August 2020

Three trials involving the nematode Heterorhabditis bacteriophora (Poiner) provided convincing evidence that this entomopathogenic nematode can provide highly effective control of black vine weevil larvae under conventional methods of container plant production. In all trials, the application of nematodes significantly reduced populations of weevil larvae relative to levels found in the untreated containers. The first and second trials, using Bergenia and Heuchera, confirmed that H. bacteriophora applied at two rates caused substantial mortality to black vine weevil larvae. The third trial revealed that H. bacteriophora applied to Epimedium provided levels of control comparable to those of imidacloprid and acephate. In all trials, populations of weevil larvae were reduced by 90–100% following the application of H. bacteriophora.
Effect of High pH on Foliar Chlorosis and Growth of Five Betula Species
Authors: McNamara Steve , Pellett Harold
Published: August 2020

The relative alkalinity tolerances of yellow birch, sweet birch, river birch, paper birch, and Japanese white birch were evaluated by comparing foliar chlorosis and growth of seedlings irrigated for 56 days with either a pH 6.0 nutrient solution (control) or K2CO3-amended solutions adjusted to pH 7.3 or 8.3. Both visual ratings and SPAD-502 chlorophyll meter measurements were effective methods of quantifying the severity of alkalinity-induced foliar chlorosis. Eight weeks of the pH 8.3 treatment was more effective than 4 weeks of the same treatment or 4 or 8 weeks of the pH 7.3 treatment for detecting differences in alkalinity tolerance among the species. Treatment for 8 weeks with either pH 7.3 or 8.3 solutions increased foliar chlorosis of sweet, river, paper, and Japanese white birch seedlings relative to the control treatment, whereas yellow birch seedlings exhibited mild chlorosis only in the pH 8.3 treatment. Based upon severity of chlorosis, yellow birch was most tolerant of soil alkalinity, sweet birch was least tolerant, and river, paper and Japanese white birch were intermediate in tolerance. Stem relative growth rates and shoot and root cumulative dry mass values did not consistently corroborate the relative alkalinity tolerances of the birch species indicated by the chlorosis and chlorophyll data, possibly because of container restriction of root growth of the more rapidly growing species. Results of this study indicate that yellow birch may be valuable for developing new birch cultivars adapted to alkaline soils.
Evaluation of Sulfentrazone for Weed Control and Phytotoxicity in Field-Grown Landscape Plants
Authors: Collins Kimberly B. , McNiel Robert E. , Weston Leslie A.
Published: August 2020

Research was conducted in 1996 and 1997 at the Horticulture Research Farm in Lexington, KY, to evaluate full season weed control and phytotoxicity for rates of sulfentrazone alone and in combination with Gallery (0.55 kg ai/ha) (0.49 lb ai/A), Treflan (2.18 kg ai/ha) (1.94 lb ai/A), and Pennant (3.27 kg ai/ha) (2.92 lb ai/A). In general, by 12 WAT, control provided by all treatments was only fair to moderate. The greatest reductions in weed cover were observed with the high rate of sulfentrazone (0.55 kg/ha) (0.49 lb ai/A), the combination of sulfentrazone (0.41 kg/ha) (0.37 lb ai/A) plus Pennant, and combinations of sulfentrazone plus Treflan. In all cases, weed control was improved with the use of a higher rate of sulfentrazone, and not necessarily associated with the presence of the partner herbicides. Phytotoxicity was mainly associated with contact of the herbicide with developing foliage, but sulfentrazone was particularly damaging to the herbaceous species Liriope and Hemerocallis, where damage was observed throughout the plants. Sulfentrazone was present in all cases where plants exhibited severe phytotoxicity in response to herbicide treatment. The most sensitive species evaluated in this study were: Abies, Liriope, and Hemerocallis. The most tolerant species included: Fraxinus, Crataegus, and Euonymus. Postemergence directed applications or shielded preemergence applications of sulfentrazone were recommended to possibly decrease phytotoxicity to sensitive species.
Seasonal Planting, Root Regeneration and Water Deficits of Austrian Pine and Arborvitae
Authors: Larson M.M.
Published: August 2020

Austrian pine (Pinus nigra) and arborvitae (Thuja occidentalis) (both 3 year old stock) were lifted and outplanted at 2 locations in northern Ohio (Wooster and Green Springs) in mid-October (early fall), mid-November (late fall) and late April (spring). At the nursery, one-half of the trees were packed in moist peat moss and the other half were root-dipped in a starch-polyacrylonitrile gel before shipment to the planting site. Samples of trees were also placed in a growth chamber in order to determine root regeneration (RR) after 4 weeks.

For Austrian pine, first-year survival of early fall, late fall, and spring planted trees averaged 15, 60, and 91%, resp. In the growth chamber, only 12% of early-fall planted pines regenerated new roots after 4 weeks, and needle water deficits (NWD) exceeded 25%, a critical value for survival. Root regeneration of spring planted trees was 60% in the growth chamber.

On June 5, average NWD of fall planted Austrian pines at Wooster was well above 25%, while that of spring planted trees was below 25%. For all pines, few trees broke bud and shoot growth was poor the first year.

For arborvitae, survival of fall- and spring-planted trees was not significantly different; mean survival was 94% for all trees in the study. However, fall planted trees showed reduced RR in the growth chamber and first-year height of field planted trees averaged 22% less than that of spring planted trees.

Survival of seedlings of both species root-dipped in starch-polyacrylonitrile gel before planting survived no better than that of undipped trees.

Poor performance of Austrian pine outplantings in Ohio, especially fall plantings, is probably due to poor RR followed by excessive NWD. Cultural methods that increase root regeneration of outplanted stock are needed.
Characterization of Soil Compaction at Construction Sites and Woody Plant Response
Authors: Alberty C.A. , Pellett H.M. , Taylor D.H.
Published: August 2020

This study was designed to quantify soil compaction occurring at construction sites and determine the effect of soil compaction on woody plant growth. Soil compaction was measured at 12 sites including residential, commercial, and new road construction. Methods of measurement included bulk density, determined with a nuclear densiometer and by the rubber balloon method, and penetrometer resistance. Bulk density in the construction zone averaged 0.50 g/cm3 (33.09lb/ft3) higher than in an adjacent undisturbed area. Bulk density readings in the construction zone were in the range that has been found to restrict growth of woody plants. Penetrometer resistance was higher in the construction zone, but this was a less reliable method of measure than bulk density for this type of site. A field study was conducted to determine the effect of compaction and puddled soil on the growth of Forsythia ovata Nakai and Cornus sericea L. Treatments included puddled soil and low, medium, and high levels of compaction. Although levels of bulk density achieved in the field plots were lower than those observed at construction sites, growth of both species was reduced by all treatments compared to the check.
Tolerance of Citrus Rootstocks to Preemergence Herbicides
Authors: Singh Megh , Achhireddy Nagi R.
Published: August 2020

Seven preemergence herbicides, Lasso (alachlor), Surflan (oryzalin), Devrinol (napropamide), Solicam (norflurazon), Goal (oxyfluorfen), Treflan (trifluralin), and Ronstar (oxadiazon) all at 1.1 and 2.2 kg/ha (1.0 and 2.0 lb/A) were evaluated for weed control and phytotoxicity to Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.], Trifoliate orange [Poncirus trifoliata (L.) Raf.] and Swingle citrumelo [Poncirus trifoliata (L.) Raf. × Citrus paradisi Macf.] citrus rootstock seedling. Goal (oxyflurofen) was most effective in controlling weeds, but was also phytotoxic to all 3 rootstocks. Surflan (oryzalin) provided satisfactory weed control (about 70%) without any phytotoxicity to citrus rootstocks but Lasso (alachlor) and Devrinol (napropamide) did not effectively control the weeds. Carrizo citrange was most susceptible to Goal (oxyfluorfen), while Swingle citrumelo was more sensitive to Treflan (trifluralin) and Ronstar (oxadiazon). Trifoliate orange was intermediate in tolerance to all herbicides. Some herbicide treatments reduced the plant height but not the trunk diameter of Carrizo citrange and Swingle citrumelo. Trunk diameter of Trifoliate orange was significantly reduced by herbicide treatments, but was unaffected in Carrizo citrange and Swingle citrumelo.
Transplanting Success with Creosotebush (Larrea tridentata (D.C.) Cav.) from Native Stands
Authors: Tipton J.L. , Taylor R.M.
Published: August 2020

The effects of season, root pruning, and transpiration reduction techniques (anti-transpirant spray with and without foliar pruning and foliar pruning alone) on percent survival and rank of creosotebush (Larrea tridentata) transplanted from a native stand were estimated. Only season had a significant impact on survival determined 6 months after transplanting. Survival was higher in spring, summer, and fall than in winter. With regard to shrub rank 6 months after transplanting, there was no significant advantage over the most economical treatment combination of not root pruned-foliar pruned. Within this combination the spring and fall transplants were superior to winter transplants with summer transplants intermediate.
Evaluation of Biorational Products for Powdery Mildew Management in Cornus florida
Authors: Mmbaga Margaret T. , Sheng Hongyan
Published: August 2020

Between 1997 and 1999, 21 biorational products were evaluated for powdery mildew control on dogwood seedlings and compared with the traditional fungicides Banner® (propiconazole), ConSyst™ WDG (chlorothalonil and thiophanate methyl) and Cleary's 3336 F® (thiophanate-methyl) in a shadehouse environment. Selected products were also evaluated in rotation with Banner®, where Banner® application was made once for every three applications. Among the biorational products the household soaps, Palmolive®, Ajax®, and Equate®, the potassium bicarbonate salt Armicarb™, and the antitranspirant Vapor Gard® were most effective in reducing powdery mildew severity. However, Vapor Gard® stunted plant growth, and Palmolive® caused some phytotoxicity. While Safer Soap®, M-Pede®, Triact™, Neem Gold®, Kaligreen™, and Ultrafine® oil were not as effective in controlling powdery mildew as the fungicides, the increase in plant growth was similar. Spray regimes that included the biorational and Banner® generally gave better disease control and enhanced plant growth over the biorational products alone. While Banner® and ConSyst™ were highly effective in controlling powdery mildew, Cleary's 3336 F® gave inconsistent results and proved only moderately effective. Overall, plant growth correlated negatively with powdery mildew severity for the biorational products (r = −0.58) and biorational/Banner rotation (r = −0.54).
Seed Germination of Southern Seaoats (Uniola paniculata) as Influenced by Stratification, Temperature, and Light
Authors: Burgess Tyler L. , Blazich Frank A. , Nash David L.
Published: August 2020

Seeds of southern seaoats (Uniola paniculata L.) were removed from storage at 4C (39F) and stratified (moist-prechilled) for 0, 15, or 30 days at 4C (39F). Following stratification, seeds were germinated at 25C (77F) or 30C (86F) or at 8/16 hr thermoperiods of 30/20C (86/68F) or 35/25C (95/77F) with daily photoperiods at each temperature of 0 (total darkness), 2, 4, 8, 12, or 24 hr. Germination was recorded every 3 days for 30 days. Light had no effect on germination. Regardless of photoperiod the influence of light was nonsignificant (P = 0.45). On the other hand, temperature and stratification were significant (P = 0.0001) and there was a significant interaction (P = 0.001) between the two parameters. Averaged across all treatments, the highest total germination was realized at 35/25C (95/77F) (60%) followed by 30/20C (86/68F) (48%), 30C (86F) (37%), and 25C (77F) (31 %). Stratification was not a requirement for germination but stratification for 15 days increased the rate of germination but not total germination. However, stratification for 30 days decreased germination due to seed decay caused by fungal growth despite seed treatment with 1.3% sodium hypochlorite prior to stratification. Seed decay during germination was observed and treatments to reduce decay should be investigated since viability tests with 2,3,5-triphenyltetrazolium chloride (TTC or TZ) indicated that initial seed viability was >95%.
Fertilizer Formulation and Method of Application Influence Bedding Plant Growth and Nitrogen Leaching in Urban Landscapes
Authors: Altland James E. , Gilliam Charles H. , Edwards James H. , Keever Gary J. , Fare Donna C. , Sibley Jeff L.
Published: August 2020

Two experiments were conducted to evaluate fertilizer formulation, method of application, and frequency of application on growth of landscape bedding plants and nitrogen (N) leaching. In the first experiment, ‘Peppermint Cooler’ vinca (Catharanthus roseus (L.) G. Don ‘Peppermint Cooler’), ‘Bonanza Yellow’ marigold (Tagetes patula L. ‘Bonanza Yellow’), and ‘Hawaii Blue’ ageratum (Ageratum houstonianum Mill. ‘Hawaii Blue’) were planted in raised beds. Four inorganic fertilizer formulations used included 13N–5.6P–10.9K (13–13–13) and 15N–0P–12.6K (15–0–15) granular water soluble (GWS) fertilizers, Osmocote 14N–6.0P–11.6K (14–14–14) (3 to 4 month release) controlled-release fertilizer (CRF), and Osmocote 17N–3.0P–10.1K (17–7–12) (12 to 14 month release) CRF. Each fertilizer was applied at a rate of 4.9 g N/m2 (1 lb N/1000 ft2) either incorporated into the top 10.2 cm (4 in) pre-plant or topdressed postplant. Additional treatments included an industry practice of incorporating 13N–5.6P–10.9K (13–13–13) pre-plant and topdressing 17N–3.0P–10.1K (17–7–12) post-plant; and a pre-plant incorporation of an organically-based fertilizer composed of recycled newspaper amended with chicken manure (caged layer manure). In Expt. 2, a similar experimental setup was used with ‘Peppermint Cooler’ vinca, ‘Red Vista’ salvia (Salvia splendens F. Sellow ex Roem. & Schult. ‘Red Vista’), and ‘Strata’ salvia (Salvia farinacea Benth. ‘Strata’). Inorganic fertilizers were applied in either single or multiple applications. Inorganic fertilizers included 15N–0P–12.6K (15–0–15) GWS fertilizer, Osmocote 14N–6.0P–11.6K (14–14–14) CRF, and Osmocote 17N–3.0P–10.1K (17–7–12) CRF. Three organically-based fertilizers were applied pre-plant and were composed of recycled newspaper amended with either chicken, beef cattle, or dairy cow animal manures. Summarizing across both experiments, plants treated with GWS fertilizers appeared to benefit with improved foliar color from immediate release of nutrients, while those treated with CRFs required at least 4 weeks to achieve dark foliar color. Nutrient leaching below plant roots was greater for GWS compared to CRFs. The industry practice treatment provided some improved plant growth in both experiments; however, it also caused initially high levels of soil-water-N (SWN) in Expt. 1. The organically-based fertilizer resulted in larger, more attractive (higher foliar color ratings) plants than inorganic fertilizers, though it also resulted in the highest levels of SWN compared to all other treatments.
Lignification Associated with Decreased Adventitious Rooting Competence of English Ivy Petioles
Authors: Reineke Richard A. , Hackett Wesley P. , Smith Alan G.
Published: August 2020

English ivy (Hedera helix L.) was used to study the relationship between lignin accumulation and adventitious rooting. Juvenile-phase and three chronological ages of mature-phase petioles were collected from clonal stock plants, analyzed for quantity of vascular lignin, and placed in an in vitro rooting assay. Rooting competence was determined by observing the number of roots formed per petiole. The number of roots per petiole differed significantly between juvenile-phase and mature-phase petioles. Lignin accumulation increased during petiole growth and development with chronologically older mature-phase petioles having the greatest amounts of lignin. There was a negative correlation between lignin accumulation and adventitious rooting competence.
Sorption of the Herbicides Isoxaben and Oryzalin to Soils and Container Media
Authors: Mervosh Todd L.
Published: August 2020

The herbicides isoxaben (Gallery) and oryzalin (Surflan) are commonly used to prevent weed emergence around ornamental plants in nurseries and landscapes. Saturated batch experiments were conducted in the laboratory to generate equilibrium sorption isotherms for these herbicides in soils and container media. Soils consisted of [A] a sandy loam containing 1.24% organic matter (by wt) after sieving, and [B] a silt loam containing 1.36% organic matter (by wt) after sieving. Container media obtained from nurseries consisted of [C] a mixture of 50% peat and 50% sand (by vol) containing 18.5% organic matter (by wt) after sieving, and [D] a mixture of 70% bark, 25% peat, and 5% fine stone (by vol) containing 34.9% organic matter (by wt) after sieving. Sorption isotherms were generated from these data. Based on sorption coefficients (Kd, Kf), container mix D sorbed both herbicides to a much greater extent than did the other substrates. Oryzalin sorption was greater than isoxaben sorption in each soil and container mix. For oryzalin, organic carbon partition coefficient (Koc) values in the soils were greater than those in the container mixes. Compositional differences in organic matter between soils and container media may account for differences in herbicide sorption in these media.
Impact of Fungicide Inputs on the Severity of Entomosporium Leaf Spot on Selections of Dwarf Indian Hawthorn
Authors: Hagan A.K. , Akridge J.R. , Rivas-Davila M.E.
Published: August 2020

In a simulated landscape planting in Brewton, AL, the impact of fungicide treatments on severity of Entomosporium leaf spot was assessed on 13 selections of Indian hawthorn, which range from highly susceptible to resistant to this disease. Chlorothalonil [Daconil 2787 4.17F] at 1.25 g ai/liter was applied at 2-and 4-week intervals to a randomly selected plant in each plot. The remaining plant in each plot was not sprayed and was the untreated control. From mid-winter to mid-spring in 1997, 1998, and 1999, fungicide applications were made over a 13-to 15-week period. When compared to unsprayed controls, reductions in the severity of Entomosporium leaf spot were noted on the fungicide-treated plants of nearly all selections, regardless of their susceptibility to Entomosporium leaf spot. As expected, disease severity was usually lower on those plants sprayed at 2-week rather than 4-week intervals. While chlorothalonil significantly reduced disease severity on the Entomosporium leaf spot resistant selections ‘Indian Princess’®, ‘Clara’, ‘Snow White’, ‘Olivia’™, and ‘Eleanor Tabor’™, only a limited reduction in the number of infected leaves in the canopy and perhaps a minor reduction in premature leaf loss were seen. In contrast, substantially less leaf spotting and defoliation on the selections such as ‘Spring Rapture’®, ‘White Enchantress’®, ‘Enchantress’®, ‘Heather’, ‘Harbinger of Spring’®, ‘Pinkie’, and ‘Bay Breeze’® were obtained with chlorothalonil, particularly when this fungicide was applied at 2-week intervals. When treated with chlorothalonil at 2-week intervals, disease severity on susceptible selections was, however, comparable to the damage levels observed on the unsprayed leaf spot resistant selections. When compared with costly and labor-intensive fungicide inputs, production and establishment of disease resistant selections is the preferred strategy for preventing destructive outbreaks of Entomosporium leaf spot on Indian hawthorn in the nursery and landscape.
Evaluating Recovery of Cupressaceae Taxa After Flooding at Contrasting Temperatures
Authors: Holland Bradley T. , Warren Stuart L. , Ranney Thomas G.
Published: August 2020

Chamaecyparis are ornamental plants that are used extensively in temperate-zone landscapes worldwide. However, due to their low tolerance to environmental stresses Chamaecyparis often perform poorly in urban landscapes. The objective of this research was to evaluate rootstocks of selected Cupressaceae taxa to determine their adaptability to poor drainage and high temperatures found commonly in urban landscapes. To accomplish this objective, 10 taxa (Chamaecyparis, Platycladus, Thuga spp., and x sCupressocyparis leylandii) were grown in 2.8 liter (#1) black plastic containers with a pinebark:sand (8:1 by vol) medium for 19 weeks in two greenhouses with 9/15 hr day/night temperatures of either 22/18C (72/64F) or 30/26C (86/79F). Half the plants in each greenhouse were flooded for 4 weeks. Root relative growth rate (RGR) was a better indicator of plant performance under flooded conditions compared to shoot RGR. At 22/18C (72/64F), root RGR of Chamaecyparis thyoides and Thuja ‘Green Giant’ only declined 10% and 11% between nonflooded and flooded plants, respectively. Chamaecyparis obtusa and x Cupressocyparis leylandii had the largest percentage decline in root RGR from nonflooded to flooded plants with 71% and 213%, respectively. Chamaecyparis thyoides had the highest root RGR at 30/26C (86/79F) in both nonflooded and flooded conditions with a 19% decrease in root RGR between nonflooded and flooded. Chamaecyparis lawsoniana and T. ‘Green Giant’ were ranked 2 and 3 in flooded conditions at 30/26C (86/79F); however, percentage decline increased to 43% and 46%, respectively. At this temperature, the remaining seven taxa had greater than 50% decline in root RGR in flooded conditions compared to nonflooded plants. In nonflooded conditions, shoot and root RGR of all species decreased from 22/18C (72/64F) to 30/26C (86/79F) except for Chamaecyparis thyoides. The shoot and root RGR of Chamaecyparis thyoides grown in 22/18C (72/64F) and 30/26C (86/79F) were similar in nonflooded conditions. Chamaecyparis thyoides demonstrated excellent tolerance to flooding and temperature and could be a desirable understock for other Chamaecyparis when grown in poorly drained locations.
Chilling Affects Budbreak of Ginkgo biloba L.
Authors: Wilson Jeffrey C. , Altland James E. , Sibley Jeff L. , Tilt Ken M. , Foshee Wheeler G.
Published: August 2020

The effects of chilling and heat on budbreak of Ginkgo biloba L. seedlings were evaluated in a study initiated on October 1, 1999, and terminated on April 8, 2002. Chilling was a determinate factor in foliar budbreak for G biloba. Thirteen levels of chilling were applied to trees in increments of 100 hours, with twelve replications per treatment. Once the chilling requirement had been satisfied, increased chilling led to a decreased heat unit requirement, resulting in accelerated foliar budbreak and higher budbreak percentage. Trees receiving the same treatment for three consecutive years required a minimum of 100 chill hours plus 936 greenhouse hours to initiate budbreak, and a minimum of 500 chill hours plus 1168 greenhouse hours to reach 50 percent budbreak. In years one and two, trees receiving less than 100 chill hours failed to break bud and eventually died. In year three, trees receiving less than 100 chill hours broke an average of 0.05 percent buds per tree, but no subsequent growth occurred.
Influence of Plant Growth Regulators and Herbicides on Suppression of Bermudagrass in Seashore Paspalum
Authors: Johnson B. Jack , Duncan Ronny R.
Published: August 2020

Bermudagrass encroachment into seashore paspalum continues to be a concern on golf courses, athletic fields, and other turf areas. Four field experiments were conducted in Georgia during 2000 through 2002 to determine timing, rates, and frequency of chemical treatments needed to suppress bermudagrass and determine tolerance of paspalum. Prograss applied in multiple applications during spring and summer months did not suppress bermudagrass cultivars as effectively as did tank-mixes of Prograss + Cutless. Prograss applied at the X rate [1.7 kg/ha (1.5 lb ai/A)] in four or five applications per year resulted in < 70% bermudagrass suppression on 52% of the rating dates while the injury to paspalum cultivars was > 40% at one-half the dates. Bermudagrass suppression was not consistent throughout the three year period when treated with Prograss + Cutless. However, the suppression was equal to or higher when Prograss + Cutless were applied initially at the ¾ X [1 X= 1.7 + 0.84 kg/ha (1.5 + 0.75 lb ai/A)] and followed by three to four additional ½ X applications during the spring and summer than other rates. By late summer in 2000 and 2001, the suppression of common bermudagrass from the tank-mixed treatments was ≤ 70% more times than either Tifway or TifSport bermudagrass. In some instances, the treatments caused > 40% injury to different paspalum cultivars at sometime during the spring and summer of each year. This was true when the initial ¾ X rate was followed by multiple ½ X rates. By late summer the injury to Sea Isle I was 65% in 2001 but only 40% in 2002. The injury to Sea Isle I during spring and summer was > 40% at 10 of 16 rating dates in 2001, but only once in 2002. In contrast, the injury to Sea Isle 2000 by late summer was 38% in 2001 and 15% in 2002, but did not exceed the 40% anytime either year. Injury to Excalibur also varied from the same Prograss + Cutless treatments and it was > 40% at 11of 16 rating dates in 2001, but did not exceed the 40% at anytime during 2002. Even through injury to paspalum was > 40% from these rates for a number of dates during spring and summer, it was within an acceptable range (≤ 40%) for all cultivars by late summer except Sea Isle I in 2001 (65%). Tank-mixes of Prograss + Primo did not improve bermudagrass suppression when compared with tank-mixes of Prograss + Cutless. The safety of paspalum cultivars to tank-mixes of Prograss + Cutless was not improved with Fe + N compared with Prograss + Cutless alone. All Envoy, Arsenal, Fusilade, and Prograss + Fusilade treatments severely injured (> 70%) all paspalum cultivars and should not be applied to a mixed bermudagrass-paspalum turf for bermudagrass suppression.
Diuron: Postemergence Oxalis Control in Container-grown Plants
Authors: Simpson Carey V. , Gilliam Charles H. , Altland James E. , Wehtje Glenn R. , Sibley Jeff L.
Published: August 2020

Three experiments were conducted to evaluate the effectiveness of postemergence applied diuron (Direx 4L) for oxalis control and crop safety in container nursery crops. The first experiment, treated on March 15, 2001, evaluated diuron at 0.14, 0.28, 0.56, and 1.12 kg ai/ha (0.125, 0.25, 0.5, and 1.0 lb ai/A) rates without a surfactant and provided a maximum of 74% oxalis control in liriope and 57% in camellia. Diuron caused slight to no injury on ‘Pink Icicle’ camellia, ‘Anthony Waterer’ spirea and ‘Big Blue’ liriope which dissipated completely by 60 DAT. Experiment two, treated on April 6, 2001, used higher rates and included a surfactant. Diuron provided excellent oxalis control at rates ≥ 0.56 kg ai/ha (0.5 lb ai/A) by 21 days after treatment (DAT) and reduced oxalis shoot fresh weight (SFW) and shoot dry weight (SDW) by ≥ 95%. Unlike the first experiment, no injury was observed on either liriope or camellia. Experiment three, treated on April 15, 2001, evaluated diuron rate and oxalis size on oxalis control. At 9 DAT a significant diuron rate × oxalis size interaction occurred, but at 15 and 21 DAT only diuron rate affected oxalis control for the sizes of oxalis tested. At 21 DAT, rates of 0.56 kg ai/ha (0.5 lb ai/A) and higher provided excellent oxalis control. These data indicate that diuron provides excellent oxalis control when applied postemergence in tolerant nursery crops.
Effect of Bioplex™ on Transplant Success of Non-Dormant Red Oak (Quercus rubra L.)
Authors: Sammons Jonathan D. , Struve Daniel K.
Published: August 2020

Biostimulants are used to reduce the stress associated with non-dormant (summer dug) harvest of field-grown nursery stock; however, the effectiveness of biostimulant treatment is uncertain. This study tested the effects of three application methods of Bioplex™ (a commonly used biostimulant) to container-grown red oak seedlings on whole plant transpirational water use and growth before and after root pruning. Root pruning was used to simulate field harvest; it removed 59% of the seedling's total root surface area. Bioplex™ application by foliar spray, soil drench or a combination of foliar spray and soil drench, significantly reduced whole plant transpirational water use by 15% for three days after application, relative to untreated control seedlings. Root pruning significantly reduced whole plant transpiration, compared to non-root-pruned seedlings, and had a greater effect on transpiration than any Bioplex™ treatment. The previous season's Bioplex treatment had no effect on the spring growth flush following fall root pruning. Root pruning in fall significantly reduced root and total plant dry weights the following spring. Although Bioplex™ applications significantly reduced transpiration for three days after application, there does not seem to be any long-term beneficial effect when used to mediate summer digging transplant stress.
Growth Regulation of Vinca minor
Authors: Keever Gary J. , Clark Josh B. , Morrison Teresa A.
Published: August 2020

Multiple applications of three rates each of B-Nine/Cycocel, Sumagic, Cutless, and Atrimmec were applied to common periwinkle grown in small containers in a greenhouse to control runner growth. All plant growth regulators (PGRs) suppressed runner elongation throughout the 30-week study. However, Atrimmec at 1500 to 4500 ppm severely injured plants for up to 20 weeks, and Cutless at 30 to 90 ppm reduced the number of runners for at least 24 weeks. There were no adverse effects associated with the application of B-Nine/Cycocel or Sumagic at the rates tested, 2500/1500 to 7500/1500 ppm and 15 to 45 ppm, respectively.
Species and Cultivar Influences on Infestation by and Parasitism of a Columbine Leafminer (Phytomyza aquilegivora Spencer)
Authors: Braman S.K. , Buntin G.D. , Oetting R.D.
Published: August 2020

Columbine, Aquilegia spp., are regularly attacked by agromyzid leafminers, Phytomyza spp. Effects of columbine species and cultivars on infestation by the leafminer Phytomyza aquilegivora Spencer, and subsequent parasitism by hymenopterous parasitoids was evaluated in two-year field trials at four locations in central and north Georgia. Among 20 columbine taxa planted in non-irrigated, wooded sites in central and north Georgia, two selections (A. flabellata and A. caerulea ‘Dwarf Fantasy Mix’) were comparable to the moderately resistant native species A. canadensis. In irrigated sites in central and north Georgia, all cultivars were equally infested by the leaf miner. The most heavily attacked selections among all sites were A. alpina, A. chrysantha ‘Yellow Star’, A. caerulea, A. caerulea ‘McKana mix’, A. caerulea ‘Music hybrid’, A. skinneri, and A. x hybrida ‘Ruby Port’. The variegated selection, A. vervaeneana ‘Woodside’, sustained intermediate infestation levels as did A. vulgaris ‘Winkie Blue & White’. Cultivar influences on parasitism of leafminers was quantified at two sites. Eleven species of hymenopteran parasitoids representing three families were recovered. Leafminers infesting A. chrysantha ‘Yellow Star’ were most heavily parasitized at both locations. Chrysocharis pentheus Walker was the most abundant parasitoid, representing 41% of all parasitoids collected and 48.4% of the species reared from leafminers in central Georgia. Seladerma sp. was the only parasitoid reared from leafminers collected in north Georgia and represented 22.1% of all parasitoids obtained.
Invasive Plant Species: Results of a Consumer Awareness, Knowledge, and Expectations Survey Conducted in Pennsylvania
Authors: Kelley Kathleen M. , Conklin Janine R. , Sellmer James C. , Bates Ricky M.
Published: August 2020

Consumers were surveyed at the 2004 Philadelphia Flower Show in Philadelphia, PA, from March 8–10, to quantify their attitudes and behaviors towards invasive plant species and potential problems associated with purchasing and planting them. A majority of the 341 participants (81.5%) was aware that non-native plants were used in the landscape and that these plants may be invasive in natural areas. Less than half (40.1%) acknowledged owning plants considered invasive while one third (33.5%) did not know if these plants were growing in their landscapes. Less than half (41.3%) believed that laws should be passed to prevent the sale of non-native plants while 27.8% believed that laws should be passed to allow sale of only native plants in their area. Three distinct consumer segments were identified using Cluster Analysis: ‘Invasive savvy,’ participants knowledgeable about invasives and interested in alternative species; ‘Invasive neutral,’ participants neutral in their decision to purchase alternatives to invasive plants and price sensitive about paying more for plants tested for invasiveness; and ‘Invasive inactive,’ participants were not price sensitive to paying more for plants tested for invasiveness, however, they appeared to oppose the purchase of plants previously listed as invasive which would be available as seedless through breeding and natural selection or other forms of genetic modification. Survey results indicated that media sources (e.g., television and print media) would be effective for educating consumers about potential problems associated with invasive species in the landscape.
Growth and Flowering of Crapemyrtle in Response to Tree Shelters
Authors: Brooks K.M. , Keever G.J. , Altland J.E. , Sibley J.L.
Published: August 2020

Tree shelters were evaluated as a means of accelerating height growth of tree-form crapemyrtles. In two experiments, Dynamite™ grown in shelters were 124 and 48% taller at the end of the growing season, while shelter-grown ‘Potomac’ were 61 and 50% taller. Height of ‘Tuscarora’ was not affected by tree shelters. In the first experiment calipers of sheltered and non-sheltered ‘Tuscarora’ and Dynamite™ were similar at the end of the season, while caliper of ‘Potomac’ was 35% less when grown in shelters. In the second experiment there were no caliper differences between sheltered and unsheltered Dynamite™ or ‘Potomac’ at the end of the growing season. All plants grown in tree shelters flowered later than unsheltered plants and had visibly straighter, more upright trunks with minimal lateral shoot development.
Sales, Value Added and Employment Impacts of the United States Sod Production Industry
Authors: Haydu John J. , Hodges Alan W. , Hall Charles R. , Cisar John L.
Published: August 2020

A study using government secondary data in conjunction with primary data collected through a national survey was conducted to assess the importance of the sod production industry to the United States economy. Results indicate that the 2,124 sod farms contributed over $1.72B in gross output or sales impacts to the U.S. economy, $1.31B in value added, employed 13,454 people, and paid $28.6M in indirect business taxes. The top five producing states in terms of sales impacts include Florida ($344M), Texas ($183M), Alabama ($118M), Georgia ($116M) and Oklahoma ($84M), accounting for nearly 50% of total sales.