bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth Response of Crapemyrtle to Production Light Level and Supplemental Fertilizer
Authors: Brooks K.M. , Keever G.J. , Sibley J.L. , Altland J.E.
Published: August 2020

The effects of production light level on growth of crapemyrtle were evaluated as a means of accelerating the development of tree-form crapemyrtles (Lagerstroemia spp.). By the end of the first growing season, plant height and shoot length of ‘Fantasy’ and ‘Tuscarora’ were greater when grown under 50 or 80% shade than when grown in full sun. By the end of the second growing season, height and shoot length of all three cultivars grown under one or both shade levels were greater than those of plants grown in full sun. In a second experiment, ‘Carolina Beauty’ and ‘Tuscarora’, but not Dynamite™, were taller at the end of the first growing season when grown under 50 or 80% shade than when grown in full sun. Flowering of all cultivars grown under shade was suppressed or delayed. Caliper of Dynamite™ and ‘Tuscarora’ at the end of the first growing season was greatest when grown in full sun, while production light level had no effect on caliper of ‘Carolina Beauty’. At the end of the second season, during which all plants were grown in full sun, there were no height, caliper, or flowering differences of any cultivar due to previous production light level, except for less caliper growth of ‘Tuscarora’ previously under 80% shade compared to plants grown in full sun.
Comparison of Gardening Activities and Purchases of Homeowners and Renters
Authors: Behe Bridget K.
Published: August 2020

In September 2004, an Internet survey was conducted among 1507 American homeowners and renters to compare their gardening participation and purchases. Because income level and homeownership were related, the sample was stratified to create four groups using the respondent's 2003 household income: (a) < $25,000, (b) $25,000 to $49,999, (c) $50,000 to $74,999, and (d) ≥ $75,000. Within each income group, the percentages of respondents who participated in 14 gardening-related activities and made 12 gardening-related purchases were compared. Across all income groups, a higher percentage of homeowners than renters participated in gardening-related activities and made gardening-related purchases, however as income level rose the number of differences between homeowners and renters generally declined. At the income category $25,000 to $49,999, there were 20 of 26 possible differences between homeowners and renters. At the highest income category (≥ $75,000), homeowners and renters differed in only 5 of 14 gardening-related activities and none of 12 gardening-related purchases. Given the moderate extent to which they already participate and make gardening-related purchases, greater effort should be made to increase participation and purchases among this underserved target market.
Pre-germination Seed Treatments and Stratification Affect Germination of Montezuma Cypress
Authors: Denny Geoffrey C. , Arnold Michael A.
Published: August 2020

Taxodium distichum (L.) Richard var. mexicanum Gordon (syn. T. mucronatum), Montezuma cypress, is a valuable ornamental tree species tolerant of a wide range of cultural conditions. However, little is know about the propagation requirements of this species. The objectives of this study were 1) to determine the effect of previously recommended seed treatments for baldcypress (T. distichum (L.) Richard var. distichum) or pondcypress (T. distichum (L.) Richard var. imbricarium (Nutt.) Croom; syn. T. ascendens, T.d. var. nutans) on Montezuma cypress seeds, and 2) to determine the effects of stratification in combination with pre-germination treatments on germination of Montezuma cypress seeds. Open pollinated seeds were collected from a single tree in Southmost, TX (25° 52.576’ N, 97° 27 .083’ W, elevation 4.5 m, USDA Plant Hardiness Zone 9b). Seven pre-germination treatments and three stratification periods were applied to the seeds. If immediate germination of ripe seed is desired, then the best treatments are the citric acid soak and the hot water baths, however, if seeds can be stratified, then no pre-germination seed treatment is needed. Citric acid scarification and hot water baths produced the best germination. Stratification hastened germination rates and cumulative mean germination percentages. Stratification for 45 d appears to be sufficient, although for the best pre-germination treatments stratification requirements were less pronounced.
Differences in Growth, and Nitrogen Uptake and Storage Between Two Container-Grown Cultivars of Rhododendron
Authors: Bi G. , Scagel C.F. , Fuchigami L.H. , Regan R.P.
Published: August 2020

One-year-old liners of an evergreen rhododendron (Rhododendron L. ‘H-1 P.J.M’) and a deciduous azalea (Rhododendron L. ‘Cannon's Double’) were used to determine nitrogen (N) uptake, remobilization, and storage in relation to plant growth from May to September. Plants were grown in a substrate of equal parts (by vol) vermiculite, pumice, and sandy loam soil and received liquid fertilization with or without N. Rate of N uptake was correlated with the rate of plant growth and maximum uptake occurred during July [azalea, >4 mg/day (1.4E – 04 oz/day)] and August [rhododendron, >2 mg/day (7.1E – 05 oz/day)]. Compared to the rhododendron used in this study, the azalea cultivar grew faster and had a greater rate of N uptake and uptake efficiency (azalea, 12 to 33%; rhododendron, 8 to 16%). The old leaves of the rhododendron remobilized N for new growth. New azalea leaves exported approx. 40% of their N by September when the stems and roots were actively accumulating biomass. The roots, stems and new leaves of the rhododendrons were still accumulating biomass by September. Our results suggest that transplanted 1-year-old liners of rhododendron and azalea contained sufficient N reserves in both the plant and substrate to support initial plant growth and that increasing availability of N in the substrate during the period of rapid growth can significantly increase N uptake while improving vegetative growth and the N status of both rhododendron and azalea.
Benzyladenine (BA) Promotes Ramet Formation in Hemerocallis
Authors: Amling J.W. , Keever G.J. , Kessler J.R. , Eakes D.J.
Published: August 2020

In 2000 and 2004, cultivars of Hemerocallis were treated with foliar applications of 2500 or 5000 ppm benzyladenine (BA) for 1, 2, 3, 4 or 5 consecutive weeks. In both years, BA increased ramet production of all cultivars although treatment response was cultivar dependent. In 2000, an increasing number of BA applications resulted in ‘Lavinia Love’ and ‘Beguine’ forming 1.6 to 3.2 and 0.7 to 1.1 more ramets, respectively, than control plants at 9 weeks after initial treatment (WAT), regardless of concentration. Increasing BA concentration increased ramet formation by up to one ramet in ‘Beguine’ and up to 3 ramets in ‘Lavinia Love’ at 9 WAT, regardless of the number of applications. At 9 WAT in 2004, increasing weekly applications of BA increased ramet formation in ‘Dainty Deb’ from a mean of 1.3 ramets with one application to a mean of 3.0 ramets with five applications, and in ‘Sarah Sikes hybrid’ from 0.5 ramets with one application to 2.1 ramets with five applications, regardless of concentration. Compared to control plants, ‘Dainty Deb’ increased ramet production by 1.9 ramets and 2.3 ramets at 9 WAT in 2004 when treated with 2500 ppm and 5000 ppm BA, respectively, regardless of the number of applications. Compared to untreated controls, ‘Sarah Sikes hybrid’ formed 1.1 and 1.3 more ramets when treated with 2500 ppm and 5000 ppm BA, respectively.
Effects of Container Spacing Practice and Fertilizer Placement on Runoff from Overhead-Irrigated Sweet Viburnum
Authors: Million Jeff , Yeager Tom , Albano Joseph
Published: August 2020

Information on how management practices affect runoff volume and nutrient content is needed to improve irrigation and fertilizer efficiency while minimizing environmental impacts. Runoff (leachate plus unintercepted irrigation and rain) was collected weekly for 20 weeks during production of sweet viburnum (Viburnum odoratissimum (L.) Ker-Gawl.) in trade #1 (2.7 liter) containers fertilized with 15 g (0.53 oz) of a resin-coated, controlled-release fertilizer Osmocote 18N–2.6P–10K (18–6–12), 8–9 month 21C (70F)] and overhead-irrigated with water at 1 cm/day (0.39 in). Treatments were a factorial arrangement of two container spacing practices [spaced at planting (SP) or spaced midseason (SM)] and two fertilizer placement methods [incorporated (INC) or surface-applied (SURF)]. Cumulative runoff volume averaged 1590 liters/m2 (3900 gal/100 ft2) or 66% of irrigation plus rain and was 9% higher for SP than SM. A 37% reduction in shoot dry weight of SP versus SM plants was attributed to heat stress in SP containers. SURF decreased N, P, and K leaching losses (mg/container) 42, 42, and 25%, respectively, at SP and 16, 25, and 4%, respectively, at SM. Nutrient leaching losses as a percent of applied were 11–18% for N, 7–13% for P, and 19–28% for K. Total nutrient loads in runoff were 4.6–11.1 g/m2 for N, 0.48–1.25 g/m2 for P, and 5.8–10.1 g/m2 for K with peak nutrient loss occurring during the first two weeks after planting.
Plug Characteristics and Post-transplanting Container Size affect Growth of Little Bluestem and Lanceleaf Coreopsis
Authors: Watkinson Jonathan I. , Pill Wallace G.
Published: August 2020

Two studies were conducted to determine the effects of several factors on growth of containerized lanceleaf coreopsis (Coreopsis lanceolata L.) and little bluestem (Schizachyrium scoparium (Michx.) Nash.). In the first study, seeds were sown in 22 cm3 (1.3 in3) plug cells and then transplanted, with or without root disturbance (manually teasing roots from the root ball and directing them radially from the plant axis) into 3.78 liter (1 gal) containers at 35 days (young) or 49 days (old) after planting. By 35 days after transplanting, old transplants of both species had greater shoot dry weight than young ones even though the latter had greater shoot relative growth rate and shoot net assimilation rate between 0 and 35 days after transplanting (DAT). By 107 DAT, old Schizachyrium transplants had more shoot dry weight than young ones, but Coreopsis shoot dry weight was unaffected by transplant age. Root disturbance, irrespective of transplant age and species, decreased shoot dry weight at 35 DAT and decreased shoot relative growth rate between 0 and 35, but had no effect on these variables by 107 DAT. In the second study, transplants were raised in small (22 cm3, 1.4 in3) or large (84 cm3, 5.1 in3) cells, then transplanted at 62 or 76 days after planting, respectively, (to assure similar shoot size to plug cell volume ratio and to avoid root restriction) into small (15 cm, 6 in) or large (20 cm, 8 in) diameter standard pots. Shoot dry weights of both species were greater from large plug cell transplants by 35 DAT, but only of Coreopsis by 107 DAT. Large post-transplanting containers further contributed to the growth advantage of transplanting plants from large plug cells, responses that could be attributed to greater supplies of water nutrients in larger plug cells and post-transplanting containers.
Sodium Cellulose Glycolate as a Thickening Agent for Liquid Auxin Formulations can Enhance Rooting of Stem Cuttings
Authors: Blythe Eugene K. , Sibley Jeff L.
Published: August 2020

Stem cuttings of Abelia ‘Edward Goucher’, Buxus sinica var. insularis ‘Wintergreen’, Hedera helix, Hibiscus syriacus ‘Collie Mullens’, Ilex vomitoria ‘Nana’, Juniperus conferta ‘Blue Pacific’, and Rosa ‘Red Cascade’ received a basal quick-dip in solutions of Dip ‘N Grow at concentrations of 0 + 0, 50 + 25, 250 + 125, 500 + 250, 750 + 375, and 1000 + 500 ppm IBA + NAA prepared with and without 13.5 g/liter sodium cellulose glycolate (SCG) as a thickening agent. Cuttings of Ilex vomitoria ‘Nana’ exhibited increased rooting with increasing auxin concentration with inclusion of SCG. The other six taxa exhibited similar rooting percentages among all treatments, but exhibited an increase in root number and/or total root length with inclusion of SCG. Initial shoot growth on rooted cuttings of Abelia ‘Edward Goucher’ showed some reduction with increasing auxin concentration with inclusion of SCG, suggesting cuttings absorbed more auxin from solutions containing SCG owing to their extended period of exposure to the auxin. Otherwise, there were no negative responses to solutions containing SCG. The greater viscosity of solutions prepared with SCG can help reduce the possibility of spillage and evaporation of alcohol during use of the auxin solutions.
Evaluation for Resistance to Powdery Mildew in Cornus Species and Hybrids Using a Leaf Disk Assay
Authors: Li Y.H. , Windham M.T. , Trigiano R.N. , Fare D.C. , Spiers J.M. , Copes W.E.
Published: August 2020

Using a leaf disk assay, eight cultivars or/and breeding lines in Cornus florida L., C. kousa (Buerger ex Miq.) Hance, five cultivars in C. kousa × C. florida, one cultivar in C. kousa × C. nuttallii Aud. and one cultivar in (C. kousa × C. nuttallii) × C. kousa were evaluated for resistance to powdery mildew [Erysiphe pulchra (Cooke and Peck) U. Braun & S. Takamatsu (syn. Microsphaera pulchra Cooke and Peck)]. Flowering dogwoods (C. florida) cultivars were more susceptible than the other species and hybrids with the exception of the C. florida × C. kousa hybrid ‘Ruth Ellen’. Resistance in kousa dogwoods and hybrids was manifested as restriction of hyphal growth and inhibition of sporulation. Although mildew colonies and sporulation were detected on leaves of all flowering dogwood cultivars, ‘Karen's Appalachian Blush’ and ‘Worlds Fair’ were more resistant than other cultivars. These dogwoods had significantly lower values of percent geminated conidia with branched hyphae, infection efficiency, sporulation and delayed latent period. The leaf disk assay provides a laboratory procedure to screen new cultivars and lines of dogwoods for resistance to powdery mildew.
Multiple Cyclanilide Applications Promote Branching of Woody Ornamentals
Authors: Holland A.S. , Keever G.J. , Kessler J.R. , Dane F.
Published: August 2020

Multiple weekly or biweekly applications of 0, 100, 200 or 300 ppm cyclanilide (CYC), a bioregulator effective in stimulating branching of apple and cherry trees and select woody ornamental shrubs, were applied foliarly to eight species or cultivars of woody landscape shrubs, five of which showed increased branching in response to treatment. Shoot number increases were concentration and species dependent, and compared to untreated controls, branching at 60 days after first treatment (DAFT) with three weekly applications of 100 to 300 ppm CYC in 2005 increased from 1400 to 1900% in ‘Brandy's Temper’ sasanqua camellia, 114 to 175% in ‘Sky Pencil’ holly, 385 to 458% in ‘Foster’ holly, 166 to 335% in Eleanor Taber™ Indian hawthorn, and 1885 to 2230% in ‘Olivia’™ Indian hawthorn. In 2006, branching 60 DAFT with three biweekly applications of 100 to 300 ppm CYC increased 34 to 73% in ‘Foster’ holly, 268 to 413% in Eleanor Taber™ Indian hawthorn, and 2540 to 4440% in Olivia™ Indian hawthorn. Plant size often decreased with increasing CYC concentration, but not in all species or cultivars. Injury to new foliage of ‘Brandy's Temper’ camellia and ‘Sky Pencil’ and ‘Foster’ holly occurred in 2005, and to new foliage of Eleanor Taber™ and Olivia™ Indian hawthorn in both 2005 and 2006, however symptoms were transient and no longer evident by 120 DAFT. Quality of treated responsive plants at 120 DAFT was usually higher than that of untreated plants, and CYC-induced treatment effects generally persisted until the end of the growing season.
IBA Formulation, Concentration, and Stock Plant Growth Stage Affect Rooting of Stem Cuttings of Viburnum rufidulum
Authors: Griffin Jason J.
Published: August 2020

Viburnum rufidulum Raf. (southern or rusty blackhaw) has potential to be a popular landscape plant as it is an attractive large shrub tolerant of many common landscape stresses. However, propagation difficulties have thus far limited wide scale use. Therefore, the influence of IBA formulation and concentration on adventitious rooting of stem cuttings of southern blackhaw taken at different stock plant growth stages throughout the year were investigated. Liquid formulations of the potassium salt (K-salt) of indolebutyric acid (K-IBA) at 0, 3000, 6000, or 9000 ppm (0, 0.3, 0.6, or 0.9%) as well as talc formulations of IBA at 1000, 3000, or 8000 ppm (0.1, 0.3 or 0.8%) were utilized. Talc formulations failed to stimulate rooting regardless of concentration or growth stage. A quick-dip of K-IBA increased rooting percentage at all growth stages. Softwood and hardwood cuttings had the highest rooting percentages. Hardwood cuttings treated with 6000 ppm (0.6%) or 9000 ppm (0.9%) rooted 90 and 100%, respectively. Softwood cuttings treated with 6000 ppm (0.6%) rooted 87%. K-IBA improved root number per rooted cutting for softwood cuttings, whereas root length was unaffected by K-IBA at any growth stage.
Utilization of Mixed Municipal Solid Waste Compost as a Soilless Potting Component in Greenhouse Production of Four Floricultural Crops
Authors: Lu Wenliang , Yang Xiaomei , Sibley Jeff L. , Gilliam Charles H. , Bannon James S. , Zhang Yaoqi
Published: August 2020

Mixed municipal solid waste compost (MSWC) was evaluated as a soilless potting mix component for greenhouse production using four floricultural crops: dusty miller (Senecio cineraria), hybrid petunia (Petunia × hybrida), Japanese holly fern (Cyrtomium falcatum), and begonia (Begonia × semperflorens-cultorum). Dusty miller and petunia plugs were transplanted into 36-cell trays filled with MSWC based substrates and grown for two months. Petunia only grew well in the blend with the lowest MSWC ratio (33%), while dusty miller grew well in all MSWC blends. Japanese holly fern and begonia liners were transplanted into 15 cm (6 in) azalea pots and grown for 12 weeks in five substrates: 100% pine bark (PB), 3: 1 PB: MSWC, 1: 1 PB: MSWC, 1: 3 PB: MSWC, and commercially available Fafard 3B Mix. In addition to substrate, a controlled-release fertilizer was applied at two rates to form a two-way factorial completely randomized design. Replacement of PB with MSWC resulted at least equal plant quality and growth of begonia in the aspects of growth index, leaf greenness (SPAD value), flower number, visual rating, and shoot fresh and dry weight. For Japanese holly fern, replacement of PB with MSWC resulted in a lower visual rating, but without other negative responses in plant. For the four greenhouse crops tested, plant growth and quality were seldom negatively affected at low ratios of MSWC (25 to 33%o). However, our studies indicate the impact of blending traditional pine bark with higher than 50% MSWC is species specific.
Nitrogen Nutrition of Southern Seaoats (Uniola paniculata) Grown in the Float System
Authors: Norden Daniel S. , Warren Stuart L. , Blazich Frank A. , Nash David L.
Published: August 2020

Seeds of southern seaoats (Uniola paniculata L.) were removed from storage in July 2004, surface disinfested with 2.6% sodium hypochlorite (NaOCl) for 15 min, and sown in styrofoam tobacco (Nicotiana tabacum L.) float trays (flats) filled with a vermiculite-based hydroponic substrate. Trays were floated in plastic tubs (one tray per tub) containing a complete nutrient solution with nitrogen (N) at 10, 60, 120, 180, or 240 mg·L−1 (ppm) from a 2N–3.5P–1K ratio (8N–32P2O5–5K2O) liquid slow-release fertilizer. After 10 weeks the study was terminated and data recorded. Total plant, top, leaf, stem, and root dry weights increased quadratically with increasing nitrogen application rate (NAR) with maximum dry weights calculated to occur with N at 140 to 150 mg-L−1, respectively. Other growth indexes of leaf area, root length, root area, plant height, crown growth index, tiller number, and leaf number also increased quadratically with increasing NAR similar to dry weight data. Leaf area, root length, and root area were maximized with N at 157, 140, and 140 mg-L−1, respectively. Root to top ratio and specific leaf area were both unaffected by NAR. Leaf mineral nutrient concentrations of N and phosphorus responded quadratically with increasing NAR whereas, foliar mineral nutrient concentrations of potassium, calcium, sulfur, sodium (Na), manganese, zinc, and copper responded linearly to increasing NARs. With the exception of Na and iron, foliar nutrient content for all analyzed nutrients increased quadratically with increasing NAR. Calculated leaf N concentration at maximum top dry weight was 31 mg·g−1. Southern seaoats can be grown successfully using the float system with optimum N rates of 140 to 150 mg·L−1 provided by a fertilizer having a 2N–3.5P–1K ratio.
Amending a Gravel Based Growing Medium with Calcined Clay Improves Physical Properties and Seedling Growth
Authors: Bohnert Catherine A. , Starbuck Christopher , Anderson Stephen
Published: August 2020

The Missouri Gravel Bed (MGB) is a system that uses pea gravel with 10% sand (v/v) as a root growth medium, allowing plants to be removed from the gravel and planted, bare root, during the growing season. However, the low water holding capacity of the medium necessitates frequent irrigation. This study was conducted to determine the effects of amending pea gravel with calcined clay (Terra-Green®) on the physical properties of the medium and on growth of Gymnocladus dioicus (L.) K. Koch seedlings. Adding 10% sand (v/v) increased water holding capacity of the medium slightly at water tensions above 1 kPa. Gravel amended with 40% calcined clay had 16% air-filled porosity and had 3.5 times more plant available water than gravel with sand only. Dry weights of seedlings grown in gravel amended with 40% calcined clay and no sand were over twice as great as those of seedlings grown in the standard MGB medium.
Nitrogen and Flowering Dogwood. I. Impact of Nitrogen Fertilization Rate on the Occurrence of Spot Anthracnose, Powdery Mildew, and Cercospora Leaf Spot and Their Effect on Tree Growth
Authors: Hagan A.K. , Akridge J.R. , Bowen K.L.
Published: August 2020

Impact of nitrogen (N) rate on spot anthracnose, powdery mildew, and Cercospora leaf spot as well as their impact on the growth of field-grown ‘Cloud 9’ and ‘Cherokee Chief’ flowering dogwood was assessed in 2003, 2004, and 2005. From 2001 to 2005, ammonium nitrate was applied at 4.1, 8.3, 16.5, 33.0 and 66.0 g N·m−2 (37.5, 75, 150, 300, 600 lb N·A−1). Heritage 50W fungicide was applied to one ‘Cherokee Chief’ and ‘Cloud 9’ flowering dogwood in each plot, while the second was untreated. Powdery mildew and Cercospora leaf spot were impacted by N rate more than spot anthracnose. In two of three years, powdery mildew intensified, particularly on the non-treated trees, as N rates increased. Cercospora leaf spot intensity (AUDPCI) and defoliation (AUDPCD) on the fungicide-treated and non-treated trees was influenced by N-rate in two of three and one of three years, respectively. Regardless of fungicide treatment, Cercospora leaf spot incited leaf spotting and defoliation was often lower at the two highest than the two lowest N rates. A reduction in the bract and leaf spot phases of spot anthracnose at the highest N rate was noted in 2004. While spot anthracnose was negatively correlated with trunk diameter in all three years and tree height in 2003 and 2004, Cercospora leaf spot intensity and defoliation were negatively correlated with tree height and trunk diameter in all three and two of three years, respectively. Powdery mildew had no impact on tree height or trunk diameter. Heritage 50W not only controlled spot anthracnose and powdery mildew but also slowed Cercospora leaf spot development sufficiently to enhance leaf retention and fall color.
Nitrogen and Flowering Dogwood. II. Impact of Nitrogen Fertilization Rate on Flower Bud Set and Tree Growth
Authors: Hagan A.K. , Akridge J.R. , Bowen K.L. , Gilliam C.H.
Published: August 2020

Impact of nitrogen (N) fertilization rate on the growth of ‘Cloud 9’ and ‘Cherokee Chief’ flowering dogwood was assessed in a field planting from February 2001 until January 2006 in southwest Alabama (USDA Zone 8a). Starting at planting in 2001 and ending in 2005, ammonium nitrate was broadcast in a 0.3 m2 circle around the base of each tree at 4.1, 8.3, 16.5, 33.0 and 66.0 g N·m−2 (37.5, 75, 150, 300, 600 lb N·A−1) with the application of half of each N-rate in April and June of each year. In each year, disease control was maintained with approximately six applications of Heritage 50W fungicide made at 2-week intervals. Trunk diameter and tree height were recorded in early-winter from 2001 through 2006; flower bud counts were taken annually from 2003 to 2006. With the exception of 2004 when N rate had not influence on bud formation, highest flower bud counts were associated with elevated rates of 33 and 66 g N·m−2 (300 and 600 lb·N−2). Nitrogen rate had no influence on the height or trunk diameter of flowering dogwood until three and four years, respectively, after planting. Impact of N rates below 66.0 g N·m−2 (600 lb·A−1) per year on tree height was minimal. In 2005 and 2006, trunk diameter was greater for trees receiving the two highest than the two lowest N rates. Regression analysis was used to calculate optimum N rate for flower bud set, as well as change in trunk diameter and tree height.
Response of Loropetalum chinense var. rubrum ‘Ruby’ to Foliar Applications of Micronutrient Fertilizers and Miticide
Authors: Shober Amy L. , Leibee Gary , Kok-Yokomi Moh Leng
Published: August 2020

Loropetalum chinense (also called Chinese Fringebush or Chinese Witch Hazel) is commonly used in the Florida landscapes. However, in recent years, there have been increasing reports and complaints of unexplained decline throughout Central Florida. The objective of this study was to evaluate the growth and quality response of declining L. chinense plants to foliar micronutrient and miticide applications. L. chinense ‘Ruby’ plants exhibiting significant decline symptoms were treated with eight foliar fertilizer treatments (High Cu, Low Cu, Kocide® 2000 [copper hydroxide], B, Mn, Zn, and Peters S.T.E.M.) and half of the plants also received two treatments of GardenTech Sevin Concentrate Bug Killer® (carbaryl, 22.5% AI). Plant growth was not influenced by miticide or fertilizer treatments. However, plants sprayed with Cu (i.e., Cu high, Cu low, and Kocide) had quality ratings, at 4 and 8 weeks after treatment, that were significantly higher than plants treated with other foliar fertilizers. Additionally, results indicated that there was no fertilizer treatment effect on mite populations. Failure of the miticide to enhance plant quality ratings, suggested that eriophyid mites were not associated with decline symptoms. The quality of declining landscape plantings of L. chinense ‘Ruby’ can be improved with the application of foliar Cu sprays.
Clean Chip Residual as a Substrate for Perennial Nursery Crop Production
Authors: Boyer Cheryl R. , Fain Glenn B. , Gilliam Charles H. , Gallagher Thomas V. , Torbert H. Allen , Sibley Jeff L.
Published: August 2020

Pine bark (PB) for horticultural uses is becoming less available and as a result, there is a need to develop alternative substrates for continued profitability of the nursery industry. This study, conducted at Poplarville, MS, and Auburn, AL, evaluated the growth of nine perennial species in a substrate composed of a pulpwood harvesting by-product called clean chip residual (CCR) which contains approximately 50% wood fiber. Two CCR particle sizes were used alone or amended with peat moss (PM) (4:1 by vol) and compared with control treatments PB and PB:PM. Substrates composed of 100% PB or 100% CCR had high air space (AS) and low water holding capacity (WHC) which resulted in less available water to plants. Addition of PM lowered AS and increased WHC. There were no significant differences among growth indices at Poplarville for 6 of 8 species and for 3 of 7 species at Auburn, though the remaining 4 species were only slightly smaller when grown in 100% CCR. Shoot dry weight was greatest in substrates amended with PM. Results of this study indicate that acceptable growth of perennial plants can be obtained in substrates composed of CCR when compared to PB and PB amended with PM.
Nitrogen and Substrate Assessment For Pot-in-Pot Production in the Intermountain West
Authors: Gunnell JayDee , Grossl Paul R. , Kjelgren Roger
Published: August 2020

We investigated optimum nitrogen rates and different growth substrates for short-term finish production of container and bare root shade tree liners in a pot-in-pot production system in the Intermountain West. In one study, nitrogen ranging from 0–27 g N-tree−1 (0–36 lbs N·1000 ft−2) as urea was applied to quaking aspen (Populus tremuloides), ‘Autumn Blaze’ maple (Acer × freemannii ‘Autumn Blaze’), ‘Chanticleer’ flowering pear (Pyrus calleryana ‘Chanticleer’), and ‘Canada Red’ chokecherry (Prunus virginiana ‘Canada Red’). Twenty-six liter liners (#7 container) were transplanted into 57 liter (#15) containers in a retail nursery finishing pot-in-pot system. Trunk diameter growth and shoot-tip elongation measurements were recorded for one growing season. Overall, only pear had a consistent increase in terminal shoot and trunk growth in response to N at 9 g N·tree−1 (12 lbs N·1000 ft−2). Maple and chokecherry exhibited modest lateral shoot growth at 4.5 and 18 g N·tree−1 (10–24 lbs N·1000 ft−2), and aspen growth had no response to N. The second study evaluated the effect of nitrogen rates and substrate type on first-year trunk diameter growth of bare root common chokecherry (Prunus virginiana) and Aristocrat flowering pear (Pyrus calleryana ‘Aristocrat’). Large bare-root liners were installed into a finishing pot-in-pot system with three substrate treatments, a proprietary, a commercial mix using several organic matter sources, and a simple composted bark-pumice mix. Five nitrogen rates, 0–9 g N·tree−1, (0–12 lbs N·1000 ft−2) were applied to each substrate. Pear again had a modest increase in trunk growth at 2.2 g N per tree, but had no response to the different growth substrates. Chokecherry trunk growth did not increase with nitrogen nor did substrate treatment substantively affect growth. This study indicates that Intermountain West retail nurseries can likely reduce first-year nitrogen applications to container and bare root liner stock during finish production, and use a simpler media to achieve optimum growth at potentially lower cost.
Evaluation of Clay Aggregates in Perennial Offshoot Production
Authors: Pickens Jeremy M. , Fain Glenn B. , Sibley Jeff L. , Gilliam Charles H. , Olive John W.
Published: August 2020

In an effort to compare yield and time required to remove substrate from roots of liners, Ophiopogon japonicus and Ophiopogon japonicus ‘Nana’ (lilyturf) bare root bibs were potted into 100% aged pine bark, 8: 2 (v: v) pine bark: peat moss, 100% perlite, 100% fine grade Profile™ porous ceramic (Profile™ products LLC, Buffalo Grove, IL), or 100% course grade Profile™ porous ceramic. In a second study Ophiopogon japonicus was potted into 100% aged pine bark, 100% 3/16-inch HydRocks® (Big River Industries Alpharetta, GA), fine grade 100% Profile™, 100% perlite, 100% sand, 8: 2 (v: v) pine bark: peat moss, and 3: 1 (v: v) 3/16 HydRocks®: sand. In the second study, fine grade Profile™ produced the highest number of total bibs per container and bib production was similar to 8: 2 pine bark: peat moss. HydRocks® was similar to pine bark in total bibs per container but was more efficiently removed from roots. Removal of the HydRocks® substrate from plant roots required 50% less time than removal of pine bark: peat moss substrate and 51% less time than removal of pine bark substrate. HydRocks® took 23% less time to remove from roots than fine grade Profile™. Results indicate that clay materials such as HydRocks® and Profile™, when compared to conventional substrates can provide suitable yields while also decreasing labor cost by decreasing time to bare-root.
Evaluation of Systemic Insecticides for Potato Leafhopper Control in Field-Grown Red Maple
Authors: Oliver J.B. , Fare D.C. , Youssef N. , Halcomb M.A. , Reding M.E. , Ranger C.M.
Published: August 2020

Systemic insecticides and application methods were evaluated in two trials that began in 2005 and 2006 for control of potato leafhopper (Empoasca fabae [Harris]) on four red maple (Acer rubrum L.) cultivars and rated annually through 2007. Treatments evaluated in this study included surface drenches of imidacloprid plus cyfluthrin (Discus) or imidacloprid plus bifenthrin (Allectus SC), clothianidin (Arena 50WDG), dinotefuran (Safari 20SG), or thiamethoxam (Flagship 25WG); soil inserted treatments of imidacloprid formulated as an experimental tablet or as an experimental gel; or a plant root dip of Discus + Terra-Sorb hydrogel. In the 2005 trial, a one-time drench of Discus or two imidacloprid tablets significantly reduced leafhopper damage to red maple for a 3-year period. In the 2006 trial, a one-time drench of Allectus, Discus, Arena, Flagship, and Safari significantly reduced leafhopper damage for 2 years. In most cases, the Discus drench and root dip treatments were initially more effective than the imidacloprid tablets or the gel treatment. However, in general, the efficacy of imidacloprid tablet or gel treatments increased in subsequent years. Two imidacloprid tablets were more effective than one. Likewise, higher imidacloprid drench rates were more effective than lower rates. Most insecticide treatments significantly increased red maple trunk diameter, although this effect varied with cultivar and time. Allectus and Discus drench treatments significantly increased the branch and internode length of ‘Franksred’ maple in the 2005 trial. Results of this study indicate long-term potato leafhopper control with systemic insecticides and enhanced growth in red maple.
Butterfly Feeding Preferences for Four Zinnia Cultivars
Authors: Yeargan Kenneth V. , Colvin Sarah M.
Published: August 2020

Zinnias are recommended frequently for inclusion in butterfly gardens as nectar sources for adult butterflies, but little is known about butterfly preferences for different zinnia cultivars. We compared numbers and species of butterflies that visited four widely available zinnia cultivars: Zinnia violacea Cav. (formerly Zinnia elegans Jacq.) ‘Lilliput’, ‘Oklahoma’, ‘State Fair’, and Zinnia marylandica Spooner, Stimart, and Boyle ‘Pinwheel’. Mixed colors were used for all cultivars. Based on a total count of 2355 butterflies, representing 30 species, more than twice as many total butterflies visited ‘Lilliput’ than visited any of the other cultivars. Also, a greater number of butterfly species visited ‘Lilliput’ than visited any of the other cultivars. More than half of the counted butterflies belonged to the family Nymphalidae, with members of the families Pieridae and Hesperiidae being the second and third most frequent visitors, respectively.
Propagation of Eastern Redbud (Cercis canadensis) by Stem Cuttings is Influenced by Clone and Date of Cutting Collection
Authors: Wooldridge John M. , Blazich Frank A. , Warren Stuart L.
Published: August 2020

Stem cuttings of four popular clones of eastern redbud (Cercis canadensis L. ‘Ace of Hearts’, ‘Appalachian Red’, ‘Hearts of Gold’, and ‘Forest Pansy’) were taken on seven dates following budbreak during Spring and Summer 2007 and evaluated for rooting potential. Rooting was affected by a clone and cutting date interaction, indicating the optimum time to take cuttings was different for each clone. Cuttings of ‘Ace of Hearts’ taken 6 weeks after budbreak (WAB) rooted at 75 and 71% when treated with the potassium (K) salt (K-salt) of indolebutyric acid (K-IBA) at 5000 mg·liter−1 (ppm) or 15,000 mg·liter−1, respectively. In contrast, cuttings of ‘Appalachian Red’ rooted at 96 and 93% when taken 15 WAB, the last date tested for that clone, and treated with K-IBA at 5000 mg·liter−1 or 15,000 mg·liter−1, respectively. When taken 8 WAB and treated with K-IBA at 5000 mg·liter−1 or 15,000 mg·liter−1, cuttings of ‘Hearts of Gold’ rooted at 42 and 58%, respectively. Cuttings of ‘Forest Pansy’ rooted poorly regardless of collection date or K-IBA treatment. Treatment of ‘Ace of Hearts’, ‘Appalachian Red’, and ‘Hearts of Gold’ with higher K-IBA rates generally did not increase rooting percentages, but often resulted in more robust root systems. Propagation by stem cuttings may be feasible for some clones of eastern redbud, but separate protocols are necessary for each clone.
Seed Germination of Roundleaf Buffaloberry (Shepherdia rotundifolia) and Silver Buffaloberry (Shepherdia argentea) in Three Substrates
Authors: Beddes Taun , Kratsch Heidi A.
Published: August 2020

Many western native plant species occur in areas characterized by well-drained soils low in organic matter. Some drought-tolerant native plant species exhibit poor seed germination. It was hypothesized that traditional growing substrates high in organic matter may impede their germination; therefore, stratified seeds of roundleaf buffaloberry (Shepherdia rotundifolia) and silver buffaloberry (Shepherdia argentea) were sown in three substrates differing in organic matter and drainage properties. Seed flats were irrigated twice daily to container capacity, and held on a greenhouse bench for 40 days. Seeds of roundleaf buffaloberry exhibited greatest total germination in a calcined montmorillonite calcined clay substrate (66%); seeds exhibited low germination in a commercial peat-based germination mix (13%) and in a self-prepared, locally popular substrate (22%) that contained sphagnum peat: perlite: calcined clay: sand (2: 2: 1: 1 by vol). Seed germination of silver buffaloberry varied from 42 to 54% and was not different among the three substrates. When substrates are kept consistently moist, a calcined-clay substrate can improve germination of roundleaf buffaloberry, but not silver buffaloberry.
Regional Structural Change in Production and Marketing Practices for the Nursery and Greenhouse Industry: 1988–2003
Authors: Campbell Benjamin L. , Hall Charles R. , Combs Bryan F.
Published: August 2020

The U.S. nursery and greenhouse industry has undergone major changes to production and marketing practices from 1988 to 2003. Using data from national surveys that have been partially funded by HRI, we examine the regional structural changes that have occurred during this period with emphasis on sales, advertising expenditures, and computer usage. Results indicate that a structural shift has occurred for several management decisions, with other decisions experiencing only regional shifts. Key results are that marketing and advertising expenses comprise an increasing percent of total sales, with advertising mediums experiencing varying levels of change. Transaction methods have experienced various types of changes with more in-person sales in the Northern region, less in-person sales in the Southern region, and no changes for the Western region. In contrast, telephone orders have decreased in the Northern region and increased in the Southern region, while all regions experienced lower trade show sales. There has also been a move away from wholesale toward retail sales, with repeat customers continuing to represent a large share of sales. Computer usage, as expected, has experienced a considerable increase due to every-day task usage.
Benzyladenine and Cyclanilide Promote Shoot Development and Flowering of ‘Moonbeam’ Coreopsis
Authors: Farris M.E. , Keever G.J. , Kessler J.R. , Olive J.W.
Published: August 2020

Effects of cyclanilide (CYC) and benzyladenine (BA) applied as foliar sprays or substrate drenches on the growth and flowering of ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) during greenhouse production were determined. A foliar spray or substrate drench of 250 to 2000 ppm BA promoted increased numbers of vegetative shoots, reproductive shoots, and flower buds that increased with concentration. With BA concentrations of 250 or 500 ppm, flowering was delayed by 7 days or less and any foliar chlorosis was transient. Flowering delays of up to 19 days and persistent foliar chlorosis occurred in plants treated with 1000 or 2000 ppm BA. CYC applied at 25 to 100 ppm promoted fewer vegetative and reproductive shoots and flower buds than did BA; however, compared to control plants, plants developed more flower buds with no flowering delay, except when applied as a 100 ppm drench. Plants treated with CYC foliar sprays or substrate drenches developed twisted and horizontal growing shoots that persisted until full flower and detracted from the plants' appearance.
Micropropagation of Japanese Honeysuckle (Lonicera japonica) and Amur Honeysuckle (L. maackii) by Shoot Tip Culture
Authors: Osburn Lori D. , Yang Xiaohan , Li Yi , Cheng Zong-Ming
Published: August 2020

Reliable micropropagation protocols were developed for Japanese honeysuckle (Lonicera japonica Thunb.) and Amur honeysuckle [L. maackii (Rupr.) Maxim], two horticulturally important invasive woody plants. Shoot tips were collected from mature plants and established in vitro on Murashige and Skoog (MS) medium and cultured in various media. Plant growth regulators and basal media had significant effects on proliferation rates. Proliferation of Japanese honeysuckle was highest on Driver and Kuniyuki walnut (DKW) medium with 5 μM (1.1 ppm) 6-benzyladenine (BA), yielding an average of 14 axillary microshoots in 12 weeks, whereas Amur honeysuckle produced 38 axillary microshoots in 12 weeks on MS medium containing 2.5 μM (0.6 ppm) BA with or without 1.25 μM (0.3 ppm) indole-3-butyric acid (IBA). Microcuttings of Japanese honeysuckle were rooted ex vitro with or without treatment with 980 μM (200 ppm) IBA, whereas microcuttings of Amur honeysuckle required treatment with 980 μM (200 ppm) IBA to root. These protocols can be used to continuously produce plant materials for various biotechnological modifications, such as in vitro mutations and genetic engineering for noninvasiveness.
Propagation of Twelve Alaska Native Plants by Summer Stem Cuttings
Authors: Holloway Patricia S. , Peterburs Mia R.
Published: August 2020

Twelve Alaska native plants were propagated from softwood and semi-hardwood stem cuttings collected from late June through August. Cuttings of new growth were treated with 0.3% indole-3-butyric acid powder and propagated in horticultural grade perlite and vermiculite (1:1 by vol) under intermittent mist with bottom heat [26C (79F)] in a greenhouse with a minimum night temperature of 15C (59F). After 6 weeks, cuttings were harvested and evaluated for rooting percentage and root quantity. Four species rooted poorly (< 25%) regardless of collection date: Siberian alder (Alnus viridis ssp. fruticosa), silverberry (Elaeagnus commutata), Bebb willow (Salix bebbiana) and shrub birch (Betula glandulosa). Best rooting (> 80%) occurred June 20 for: Beauverd spiraea (Spiraea stevenii), sweetgale (Myrica gale), and thinleaf alder (Alnus incana ssp. tenuifolia). Peak rooting for dwarf birch (Betula nana), feltleaf willow (Salix alaxensis), balsam poplar (Populus balsamifera), Labrador tea (Ledum groenlandicum) and littletree willow (Salix arbusculoides) was early to mid July. During peak rooting times, all successful species developed adequate root quantities for survival following transplanting.
Drench Application of Cyclanilide Promotes Shoot Development in Containerized Woody Landscape Species during Nursery Production
Authors: Williamson Z. , Keever G.J. , Kessler J.R. , Olive J.W.
Published: August 2020

Cyclanilide (CYC), a plant growth regulator with cytokinin-like properties, was applied as a substrate drench to containerized woody ornamentals to determine its effects on plant growth. At 70 days after treatment (DAT) in 2005, drench applications of 50 to 1,000 ppm CYC had increased shoot development 7 to 74% for ‘Alabama Beauty’ sasanqua camellia (Camellia sasanqua ‘Alabama Beauty’), 63 to 205% for small anisetree (Illicium parviflorum), 21 to 74% for ‘Snow White’ Indian hawthorn (Rhaphiolepis indica ‘Snow White’), and 266 to 626% for ‘Sky Pencil’ holly (Ilex crenata ‘Sky Pencil’), when compared to control plants. Shoot counts the following spring, 270 DAT, increased from 16 to 101% for sasanqua camellia, 42 to 158% for small anisetree, 121 to 241% for Indian hawthorn, and 33 to 167% for ‘Firepower’ nandina, when compared to control plants. At 30 DAT foliar injury to sasanqua camellia, Indian hawthorn, and small anisetree increased with CYC concentration, and application of 500 or 1,000 ppm CYC resulted in severe injury or death of small anisetree and ‘Snow White’ Indian hawthorn. At 75 DAT in 2006, drench application of 25 to 100 ppm CYC had increased shoot counts of Eleanor Taber™ Indian hawthorn from 100 to 218%, when compared to controls, and quality ratings were highest at 130 DAT in plants drenched with 50 ppm CYC, although foliar injury ratings increased with CYC concentration at 75 and 130 DAT. At 60 DAT in 2007, application of 10 to 40 ppm CYC had increased shoot counts for ‘Snow White’ Indian hawthorn and ‘Sky Pencil’ holly 100 to 182% and 22 to 78%, respectively, and 96 to 171% and 30 to 63%, respectively at 90 to 110 DAT. In both species, quality ratings at 160 DAT increased with increasing CYC concentration. Single CYC drench applications were more persistent than previously reported single spray applications, effective at lower concentrations, and promoted shoot production in a species not responsive to single or multiple spray applications (Nandina domestica).
The Effects of Near-zero Leachate Irrigation on Growth and Water Use Efficiency and Nutrient Uptake of Container Grown Baldcypress (Taxodium distichum (L.) Rich.) Plants
Authors: Sammons Jonathan D. , Struve Daniel K.
Published: August 2020

Fertilization and irrigation practices affect water-and nutrient use-efficiencies in container-produced nursery crops. This study was conducted to determine if gravimetric monitoring of a plant-substrate-container unit could manage real-time irrigation volume to achieve a near zero leachate fraction and to study baldcypress (Taxodium distichum (L.) Rich.) growth, nutrient accumulation and water-use efficiency under a factorial combination of two irrigation leachate fractions and two controlled release fertilizer (CFR) rates. Baldcypress plants were grown at either 45 or 90 g of 15N–3.1P-12.5K (15-7-15 Multicote, six-month controlled release fertilizer top dressed on each container), and two irrigation rates, near-zero or 0.2 leachate fraction. Height growth, whole plant dry mass and shoot: root dry mass ratios, and water-use efficiency were not affected by a fertilizer and irrigation interaction. The higher fertilizer rate increased the whole plant N and K concentrations. Relative to a 20% leachate fraction irrigation regime, a near-zero leachate fraction decreased leachate volume and root, shoot and whole plant dry mass, while leachate electrical conductivity (EC), plant tissue mineral nutrient concentrations and water use efficiency increased. Although baldcypress whole plant dry mass was reduced under the near-zero leachate irrigation regime (presumably due to high soluble salt levels) there was no difference in height and stem diameter at the higher fertilizer rate between the two irrigation regimes. The near-zero leachate irrigation regime applied approximately one-half the irrigation volume of the 0.2 LF irrigation regime.