Journal of environmental horticulture最新文献

{"title":"Soil Solarization to Eradicate Soilborne Phytophthora spp. in Container Nurseries with Surface Gravel1","authors":"F. Funahashi, J. Parke","doi":"10.24266/0738-2898-38.4.158","DOIUrl":"https://doi.org/10.24266/0738-2898-38.4.158","url":null,"abstract":"\u0000 To describe the effect of soil solarization in the presence of a gravel layer on the soil surface of container nurseries, we investigated belowground temperatures and soil water potential during solarization with different thicknesses of a surface gravel layer (2.5 cm, 7.5 cm, or no gravel) (1 in, 3 in, or no gravel) in relation to survival of soilborne Phytophthora spp. inoculum. In field trials conducted for 4 weeks with Phytophthora ramorum Werres and Phytophthora pini Leonian in San Rafael, California and with P. pini in Corvallis, Oregon, infested rhododendron leaf inoculum was placed on the surface, and at 5 cm (2 in) and 15 cm (6 in) below the surface. In solarized plots with thicker layers of gravel, inoculum buried in the soil layer was killed in shorter treatment periods by higher elevated temperatures. Inoculum at the surface and within the gravel layer was also killed, but showed greater tolerance to heat under the lower water potential conditions as compared to the soil layer. P. pini has a significantly longer survival in heat than P. ramorum, allowing it to serve as a conservative surrogate for P. ramorum in testing solarization outside the quarantine facility. This study demonstrates how presence of a gravel layer influences soil solarization effectiveness in reducing Phytophthora inoculum survival.\u0000 Index words: Phytophthora ramorum, Phytophthora pini, soil disinfestation, disease management, soil temperature, soil water potential, ornamentals.\u0000 Species used in this study: Phytophthora ramorum Werres, de Cock & Man in't Veld, Phytophthora pini Leonian.","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41865572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Root Architecture in Thirty-seven Tree Species of Field Grown Nursery Stock1","authors":"G. Watson, A. Hewitt","doi":"10.24266/0738-2898-38.4.143","DOIUrl":"https://doi.org/10.24266/0738-2898-38.4.143","url":null,"abstract":"\u0000 The number and size of lateral roots of a tree seedling can be evaluated visually, and could potentially be used to select plants with better root systems early in nursery production. To evaluate how root architecture develops in young trees, root architecture of 37 species of trees was compared at two stages of development: as harvested seedlings, and then one year after replanting. The total number of lateral roots and the number of roots >2mm (0.08 in) diameter that were present on the portion of the taproot remaining on seedlings after standard root pruning were recorded. Neither could consistently predict the number of lateral roots on the root system one year after replanting. Development of roots (sum of diameters) regenerated from the cut end of the seedling taproot was equal or greater than lateral root development in 84 percent of evaluated species. Even when regenerated root development was significantly less than lateral root development, the regenerated roots still comprised up to 44 percent of the root system. Regenerated roots from the cut end of the taproot can become a major component of the architecture of the structural root system in nursery stock.\u0000 Index words: structural roots, nursery production, root regeneration.\u0000 Species used in this study: European black alder (Alnus glutinosa Gaertn.), green ash (Fraxinus pennsylvanica Marshall), quaking aspen (Populus tremuloides Michx.), European white birch. (Betula pendula Roth), river birch (Betula nigra L.), black locust (Robinia pseudoacacia L.), northern catalpa (Catalpa speciosa (Warder) Warder ex Engelm.), Mazzard cherry [Prunus avium [L.) L.], chokecherry (Prunus virginiana L.), American elm (Ulmus americana L.), Siberian elm (Ulmus pumilia L.), goldenchain tree (Laburnum anagyroides Medik.), northern hackberry (Celtis occidentalis L.), Cockspur hawthorn (Crateagus crus-galli L.), single seed hawthorn (Crateagus monogyna Jacq.), honeylocust (Gleditsia tricanthos L.), Japanese pagodatree [Sophora japonica (L.) Schott], Katsura tree (Cercidiphyllum japonicum Siebold & Zucc.), Kentucky coffee tree [Gymnocladus dioicus (L.) K. Koch], littleleaf linden (Tilia cordata Mill.), boxelder (Acer negundo L.), hedge maple (Acer campestre L.), Norway maple (Acer platanoides L.), red maple (Acer rubrum L.), silver maple (Acer saccharinum L.), sugar maple (Acer saccharum Marshall), sycamore maple (Acer pseudoplatanus L.), English Oak (Quercus robur L.), northern red oak (Quercus rubra L.), Siberian peashrub (Caragana arborescens Lam.), American plum (Prunus Americana Marshall ), Myrobalan plum (Prunus cerasifera Ehrh.), redbud (Cercis Canadensis L.), Russian olive (Elaeagnus angustifoliaI L.), tuliptree (Liriodendron tulipifera L.), black walnut (Juglans nigra L.), Japanese zelkova (Zelkova serrata (Thunb.) Makino).","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47103214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Annuals and Herbaceous Perennials Tolerant or Resistant to Phytophthora Species in the Landscape1","authors":"M. Henson, S. Sharpe, I. Meadows","doi":"10.24266/0738-2898-38.3.107","DOIUrl":"https://doi.org/10.24266/0738-2898-38.3.107","url":null,"abstract":"\u0000 Plants of one or two cultivars of 16 annuals and 14 herbaceous perennials were evaluated based on desirability and anecdotal evidence of resistance to Phytophthora root or crown rot. Six plant cultivars served as susceptible controls. Three landscape beds were established in North Carolina and each was infested with three species of Phytophthora: P. nicotianae, P. drechsleri, and P. tropicalis. Plants were regularly rated for disease incidence and symptomatic plants were assayed to determine the presence of Phytophthora species. Ten cultivars of annuals and seven cultivars of herbaceous perennials did not exhibit symptoms of Phytophthora root or crown rot or other disease throughout the season (June 4 to October 15, 2018). Phytophthora spp. were recovered from seven and six cultivars of the evaluated annuals and herbaceous perennials, respectively. Phytophthora nicotianae, P. drechsleri, or P. cryptogea were recovered from a susceptible host in each landscape bed. P. tropicalis was recovered from one plant cultivar evaluated. Phytophthora cryptogea was recovered from three plant cultivars, although this species was not intentionally introduced in the landscape beds. We identified 22 plant cultivars within 13 herbaceous plant species that grew vigorously in landscape beds infested with species of Phytophthora.\u0000 Index words: bedding plants, disease resistance, herbaceous perennials, landscape plants, Phytophthora nicotianae, Phytophthora drechsleri, Phytophthora tropicalis.\u0000 Species used in this study: yarrow (Achillea millefolium L. ‘Desert Eve Red'), fernleaf yarrow (Achillea filipendulina Lam. ‘Moonshine Yellow'), angelonia (Angelonia angustifolia Benth. ‘ArchAngel Pink', ‘Serenita White'), annual vinca (Catharanthus roseus (L.) G. Don ‘Cora Apricot', ‘Cora Strawberry', ‘Pacifica Raspberry'), celosia (Celosia argentea L. ‘New Look'), tickseed (Coreopsis auriculata L. ‘Nana', ‘Yellow Jethro Tull'), purple coneflower (Echinacea purpurea (L.) Moench ‘Cheyenne Spirit', ‘PowWow Wild Berry'), blanket flower (Gaillardia x grandiflora Hort. ‘Goblin', ‘Mesa Bi-color'), Barberton daisy (Gerbera jamesonii Bolus ex Hooker f. ‘Crazy Daisy'), verbena (Glandularia canadensis ‘Homestead Purple'), >dusty miller (Jacobaea maritima (L.) Pelser & Meijden ‘Silver Dust'), New Guinea impatiens (Impatienshawkeri W.Bull ‘Hamony', ‘Sunpatiens Compact Orchid', ‘Sunpatiens Lilac'), sweet potato vine (Ipomoea batatas (L.) Lam. ‘Ace of Spades', ‘Bright Idea Tri-color'), West Indian lantana (Lantana camara L. ‘Miss Huff'), lantana (Lantana x hybrida ‘New Gold'), shasta daisy (Leucanthemum x superbum (Bergmans ex J.W. Ingram) Bergmans ex Kent. ‘Becky', ‘Snow Lady'), bee balm (Monarda didyma L. ‘Petite Delight', ‘Jacob Cline'), ornamental grass (Panicum virgatum L. ‘Rotstrahlbusch', ‘Shenandoah'), geranium (Pelargonium x hortorum L.H. Bailey (pro. sp.) ‘Bullseye Cherry', Calliope Dark Red'), calibrachoa (Petunia x calibrachoa ‘Super Cal'), petunia (Petunia x hybrida (Hooker) ","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":"38 1","pages":"107-113"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48267702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tolerance of Three Deep South Non-turf Ornamental Groundcovers to Applications of Postemergence Herbicides1","authors":"S. Marble, Jeremy M. Pickens","doi":"10.24266/0738-2898-38.3.91","DOIUrl":"https://doi.org/10.24266/0738-2898-38.3.91","url":null,"abstract":"Ornamental groundcovers are a popular alternative to turfgrass in landscapes due to their low maintenance requirements, pest resistance, and shade tolerance. Weed control is a challenge in these groundcovers because few herbicide options are available. The objective of this research was to determine the tolerance of the groundcovers Asiatic jasmine [Trachelospermum asiaticum (Nakai) ‘Minima'], perennial peanut [Arachis pintoi (Krapov.& W.C. Greg.) ‘Golden Glory'] and dwarf mondo grass [Ophiopogon japonicus (L.f.) Ker Gawl.] ‘Nana'] to herbicides, including bentazon, clopyralid, fluazifop-P-butyl, glufosinate, halosulfuron, imazaquin, sethoxydim, sulfentrazone, and sulfosulfuron applied at approximately 2 times the label rate. Asiatic jasmine and perennial peanut were evaluated in Apopka, FL and dwarf mondo grass was evaluated in Mobile, AL. Bentazon, clopyralid, glufosinate, glyphosate, and sulfosulfuron caused unacceptable injury and/or a reduction in shoot growth for all three species while fluazifop-P-butyl and sethoxydim caused no injury to any species. Halosulfuron caused minor injury but significantly reduced growth of dwarf mondo grass. Sulfentrazone caused no injury to Asiatic jasmine or perennial peanut but caused severe injury to dwarf mondo grass after only one application. Similarly, imazaquin caused only minor injury to Asiatic jasmine and dwarf mondo grass but significantly reduced growth of perennial peanut after two applications.Index words: Postemergence herbicides, groundcovers, mondo grass, perennial peanut, Asiatic jasmine.Chemicals used in this study: Bentazon (Basagran® T/O), 3-(1-methylethyl)-1H-2, 1,3-benzothiadiazin-4(3H)-one 2,2-dioxide, clopyralid (Lontrel), 3,6-dichloro-2pyridinecarboxylic acid, fluazifop-P-butyl (Fusilade® II), (2R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid, Glufosinate (Finale®), 2-amino-4-(hydroxymethylphosphinyl)butanoic acid, Glyphosate (Ranger® PRO), N-phosphonomethyl)glycine, Halosulfuron-methyl (SedgeHammer®), methyl 3-chloro-5-[[[[4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate, Imazaquin (Sceptor® T&O), 2-[4,5-dihydro-4-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylic acid, Sethoxydim (Sethoxydim SPC), 2-[1-ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one, Sulfentrazone (Dismiss®), N-[2,4-dichloro-5-[4-difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamide, Sulfosulfuron (Certainty®), 1-(4,6-dimethoxypyrimidin-2-yl)-3-[(2-ethanesulfonyl-imidazo[1,2-a]pyridine-3-yl]sulfonylurea.Species used in this study: Asiatic jasmine ‘Minima' (Trachelospermum asiaticum ‘Minima'), perennial peanut (Arachis pintoi ‘Golden Glory'), dwarf mondo grass (Ophiopogon japonicus ‘Nana').","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43920753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ethylene Exposure Exacerbates Botrytis Damage in Cut Roses1","authors":"B. Bergmann, J. Dole","doi":"10.24266/0738-2898-38.3.80","DOIUrl":"https://doi.org/10.24266/0738-2898-38.3.80","url":null,"abstract":"\u0000 Separate experiments showed that current cut rose (Rosa × hybrida) cultivars vary considerably in Botrytis (Botrytis cinerea) susceptibility and ethylene (ET) sensitivity. There was no pattern when considering these two traits together for the 26 cultivars used, and neither trait appeared predictive of the other. Four cultivars were identified that included one each that is Botrytis susceptible/ET sensitive, Botrytis non-susceptible/ET sensitive, Botrytis susceptible/ET insensitive, and Botrytis non-susceptible/ET insensitive. Exposing these cultivars to ET often resulted in reduced vase life and more pronounced negative Botrytis responses (flower Botrytis damage, leaf Botrytis incidence, and frequency of termination due to Botrytis). This was true for ET sensitive and insensitive cultivars, Botrytis susceptible and non-susceptible cultivars, Botrytis inoculated and non-inoculated stems, and stems exposed to ET either before or after Botrytis inoculation and incubation. Thus, even if ET is not thought to have a major influence on a given cut rose cultivar in terms of classic negative ET responses (leaf drop, petal wilt, altered opening rate), ET exposure could have a significant negative impact on that cultivar by exacerbating Botrytis damage. Shipping temperatures and methods can have a strong influence on Botrytis damage, with pre-cooling of shipping boxes before cold storage/transport being beneficial.\u0000 Index words: Botrytis blight, Botrytis cinerea, cut flowers, floriculture, gray mold, Rosa L. hybrids.\u0000 Species used in this study: Rose (Rosa × hybrida) focal cultivars ‘Cuenca', ‘Daphnee', ‘Freedom', ‘Vendela'; Botrytis (Botrytis cinerea Pers. ex. Fr.).\u0000 Chemicals used in this study: 1-methylcyclopropene (EthylBloc); ethylene; silver thiosulfate.","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":"38 1","pages":"80-90"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48561458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-transplant Water Utilization of Zinnia Seedlings Grown in Humectant-amended Substrate Maintained at Two Moisture Thresholds1","authors":"B. Roberts, C. Wolverton","doi":"10.24266/0738-2898-38.3.101","DOIUrl":"https://doi.org/10.24266/0738-2898-38.3.101","url":null,"abstract":"\u0000 Humectant treatment and substrate moisture content (SMC) were studied to determine their impact on post-transplant water utilization in ‘Thumbelina' zinnia (Zinnia elegans Jacq.). Four-week-old seedlings were transplanted from plug trays into pots containing soilless substrate amended with an aqueous solution of 1.6% Hydretain® or an equal volume of water (0% humectant). Seedlings were placed in an automated, sensor-controlled irrigation system and grown for 30 days at SMC levels of 0.45 or 0.25 cm3·cm−3 (0.06 or 0.03 fl oz·oz−1). Plant-water potential (Ψw) was significantly higher (less negative) in transplants grown in humectant-treated substrate at both SMC levels, and water-use efficiency (WUE) was 2X greater for seedlings grown in treated substrate maintained at 0.25 cm3·cm−3 than it was for transplants grown in untreated substrate at the same SMC level. No significant differences in height, stem diameter or shoot dry weight were observed when comparing plants grown in treated and untreated substrate. Root dry weight was significantly greater for seedlings grown in untreated substrate. Flowering was not affected by humectant treatment or by SMC. The results show that transplanted zinnia ‘Thumbelina' seedlings require less irrigation when grown at a lower SMC threshold in soilless substrate amended with 1.6% Hydretain®.\u0000 Index words: automated irrigation control, cultural practices, plant-water relations, transplant establishment, water management, water-use efficiency.\u0000 Species used in this study: ‘Thumbelina' zinnia (Zinnia elegans Jacq.).\u0000 Chemicals used in this study: Hydretain® - a proprietary blend of sugar alcohols, polysaccharides, and neutral salts of alphahydroxyproprionic acid.","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":"38 1","pages":"101-106"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45093236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Curative Fungicide Activity Against Calonectria pseudonaviculata, the Boxwood Blight Pathogen1","authors":"J. LaMondia","doi":"10.24266/0738-2898-38.2.44","DOIUrl":"https://doi.org/10.24266/0738-2898-38.2.44","url":null,"abstract":"\u0000 Azoxystrobin, azoxystrobin plus benzovindiflupyr, kresoxim-methyl, propiconazole, pyraclostrobin, pyraclostrobin plus fluxapyroxad, tebuconazole, tetraconazole, thiophanate-methyl, and triflumizole fungicides were evaluated for curative and anti-sporulant activity against boxwood blight caused by Calonectria pseudonaviculata on detached leaves and whole boxwood plants (Buxus spp.). Pretreating detached leaves with 30 or 300 ppm a.i. 24 h prior to inoculation reduced disease compared to the untreated control for all fungicides. Fungicides were also applied 24 to 96 h post-inoculation. Only propiconazole reduced diseased leaf incidence to at least half of the control. When leaves were treated post-infection with 300 ppm propiconazole, tetraconazole, tebuconazole, or triflumizole, the pathogen did not sporulate over 2 wks. Propiconazole also reduced the percent of leaf area diseased; lesions were nearly 80% smaller with 300 ppm applied 48 h after inoculation. ‘True Dwarf' boxwood plants treated with 450 ppm thiophanate-methyl, 120 ppm pyraclostrobin or 150 ppm propiconazole 48 h after inoculation demonstrated that only propiconazole reduced the number of diseased leaves, blight lesions and the frequency of pathogen re-isolation. Experiments with ‘Green Mound' and ‘Green Mountain' boxwood cultivars and additional fungicides applied 48 h after inoculation demonstrated that propiconazole at 300 ppm, pyraclostrobin plus fluxapyroxad (150 ppm each) and azoxystrobin (135 ppm) plus benzovindiflupyr (67.5 ppm) reduced disease.\u0000 Index words: fungicide management, Buxus, chemical disease management\u0000 Chemicals used in this study: azoxystrobin (Heritage 50 WG), azoxystrobin plus benzovindiflupyr (Mural 30, 50 WG), kresoxim-methyl (Cygnus 50 WG), propiconazole (ProCon-Z 14.3 L), pyraclostrobin (Insignia 20 WG), pyraclostrobin plus fluxapyroxad (Orkestra Intrinsic 21.26 SC), tebuconazole (Torque 38.7 SC), tetraconazole (Minerva 11.6 SC), thiophanate-methyl (3336 50% WP), triflumizole (Procure 480 SC).\u0000 Species used in this study: boxwood (Buxus L.), boxwood blight (Calonectria pseudonaviculata (Crous, J.Z. Groenew. & C.F. Hill) L. Lombard, M. J. Wingf. & Crous.","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42135856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rooting Efficiency of Amur Maple Seedless Selections Produced by Mutagenesis1","authors":"A. Noyszewski, Alan G. Smith","doi":"10.24266/0738-2898-38.2.37","DOIUrl":"https://doi.org/10.24266/0738-2898-38.2.37","url":null,"abstract":"Amur maple (Acer ginnala Maxim.) is a widely planted small tree with attractive red fall foliage. In many states, it is classified as a noxious weed and regulations restrict propagation and sale, limiting customer choice. Stem cuttings are commonly used as a means of asexual propagation of Amur maple, with softwood cuttings being the easiest to root. Here we report adventitious rooting efficiency of seedless Amur maple selections using four indole-3-butyric acid (IBA; 500, 1,500, 5,000, 10,000 ppm) and four naphthalene acetic acid (NAA; 100, 500, 1,500, 5,000 ppm) treatments and a no hormone control. Overall, cuttings treated with 5,000 or 10,000 ppm IBA and 5,000 ppm NAA resulted in the highest percent rooting (PR), mean number of roots (MNR), and mean length of the longest root (MRL) across all seedless selections. Seedless selections SW-30-14 and SW-30-130 had the highest PR, 66% and 67%, respectively, and will perform well in commercial propagation. This level of rooting was greater than that of the cultivar ‘Bailey Compact’ that had 46% PR, and the seedless selection SW-30-159 that had the lowest PR (10.3%), MNR (0.3), and MRL (0.2 in) averaged across all treatments. Cuttings from 4 of the 5 seedless selections treated with 1,500 ppm NAA had the greatest PR, whereas ‘Bailey Compact’ and SW-30-159 had the greatest PR with 5,000 ppm NAA. Results indicate that rooting efficiency was impacted by mutagenesis in some selections, which may require optimization of propagation methods for those selections. Index words: adventitious rooting, auxin, vegetative propagation, sterile, non-native invasive. Species used in this study: Amur maple (Acer ginnala Maxim.). Chemicals used in this study: indole-3-butyric acid (IBA; 500, 1,500, 5,000, 10,000 ppm) and naphthalene acetic acid (NAA; 100, 500, 1,500, 5,000 ppm). Significance to the Horticulture Industry This is an ongoing project researching mutagenesis breeding of Amur maple to reduce seed production and invasiveness. Amur maple is classified as a noxious or invasive plant and regulations restrict propagation and sale of this plant limiting customer choice. The seedless selections were used to conduct this rooting experiment. Commercialization of seedless Amur maple selections requires the development of a suitable asexual propagation method; therefore, a rooting experiment was performed. Seedless selections of Amur maple produced through mutagenesis respond differently to growth hormone treatments and levels and the majority of the selections can be efficiently propagated.","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":"38 1","pages":"37-43"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49287700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ranking Resistance of Buxus Cultivars to Boxwood Blight – an Integrated Analysis1","authors":"M. Kramer, Yonghong Guo, M. Pooler","doi":"10.24266/0738-2898-38.2.50","DOIUrl":"https://doi.org/10.24266/0738-2898-38.2.50","url":null,"abstract":"Boxwood (Buxus L. spp., Buxaceae) are popular woody landscape shrubs grown for their diverse forms and broad-leaved evergreen foliage, with an estimated $126 million economic impact in the U.S. alone. Boxwood plants grown in temperate zones worldwide are now threatened by a destructive blight disease caused by the ascomycete fungi, Calonectria pseudonaviculata and C. henricotiae. While the disease can be mitigated somewhat through cultural practices and fungicides, the most sustainable long-term solution is the development of disease-resistant boxwood cultivars. Hundreds of boxwood accessions from the National Boxwood Collection at the U.S. National Arboretum were screened for resistance using a lab-based, detached-leaf assay. Initial comparisons of our results with those of multiple other disease resistance assays found inconsistent ranking of cultivar resistance among studies. We used a meta-analysis approach on compiled data from six studies and were able to produce a consistent ordering of cultivars sorted by their susceptibility to boxwood blight, despite the diversity in materials and methods of the studies. Index words: Boxwood, Calonectria pseudonaviculata, Cylindrocladium buxicola, meta-analysis, plant breeding, resistance screening. Species used in this study: Buxus bodinieri H. Lev.; B. harlandii Hance; B. microphylla Seibold & Zucc.; B. sempervirens L.; B. sinica var. insularis (Nakai) M. Cheng; B. wallichiana Baill.; Calonectria pseudonaviculata (Crous, J.Z. Groenew. & C.F. Hill) L. Lombard M.J. Wingf. & Crous 2010.","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45932017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth and Flowering of Salvia nemorosa ‘Ostfrieland' in Response to Reduced Irrigation1","authors":"A. Bayer","doi":"10.24266/0738-2898-38.2.63","DOIUrl":"https://doi.org/10.24266/0738-2898-38.2.63","url":null,"abstract":"\u0000 Reduced irrigation (RI) can conserve water and control plant growth; however, the timing of RI applications can impact plant growth and flowering. The goal of this research was to quantify growth of Salvia nemorosa L. ‘Ostfrieland' (East Friesland) in response to RI. A soil-moisture sensor automated irrigation system was used to apply four irrigation treatments: RI and well-watered (WW) controls (20% and 38% substrate water content) and two combination treatments to apply RI for either the first two weeks (20% followed by 38%, RIWW ) or final four weeks (38% followed by 20%, WWRI ) of the six-week study. Flower number, height, compactness, and relative chlorophyll content (SPAD) were not different across treatments. Average flower stem length was greater for the WW and RIWW treatments than for the RI treatment. Shoot dry weight was less for the RI treatment compared to the WW and RIWW treatments, respectively]. Cumulative irrigation volume was lowest for the RI treatment and highest for the RIWW treatment. Visually, plants in the RIWW treatment had an open, floppy habit that would likely negatively impact sales in a retail setting. Plants in the RI treatment were smaller, but visually appealing.\u0000 Index words: soil moisture sensor, plant production, herbaceous perennial, container plants.\u0000 Species used in this study: ‘Ostfrieland' salvia (Salvia nemorosa L.).","PeriodicalId":15780,"journal":{"name":"Journal of environmental horticulture","volume":"38 1","pages":"63-67"},"PeriodicalIF":0.0,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43802029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}