Verbena Canadensis Research Articles

Poultry Litter Ash Rate and Placement Affect Phosphorus Dissolution in a Horticultural Substrate1

AbstractPoultry litter ash (PLA) is a byproduct of bioenergy production and an effective P source for horticultural crops since it reduces P losses from container production due to its low P solubility. Experiments were conducted to determine effects of rate and placement of PLA on P loss from greenhouse crop production and growth and quality of two commonly-grown greenhouse crops, Verbena canadensis Britton ‘Homestead Purple' and Lantana camara L. ‘New Gold', by comparing two rates (140 and 280 g·m−3 P or 0.4 and 0.8 lb·yd−3) and two application methods (post-plant topdressed and pre-plant incorporated). Leachate-dissolved reactive phosphorus (DRP) concentrations were reduced by an average of 24% as P rate was reduced from 280 to 140 g·m−3, but were 134% less on average when PLA was topdressed instead of incorporated. Foliar P concentrations were less 33% and 44% for verbena and lantana, respectively when plants were topdressed compared to incorporated. Shoot biomass of verbena and lantana was 9% and 24% greater, respectively, when incorporating instead of topdressing PLA. As a P source, PLA should be pre-plant incorporated within the substrate at a total P rate between 140 g·m−3 (0.4 lb·yd−3) and 280 g·m−3 (0.8 lb·yd−3).Index words: phosphorus, poultry litter ash, Verbena canadensis Britton ‘Homestead Purple', Lantana camara L. ‘New Gold', dissolved reactive phosphorus.Species used in this study: ‘Homestead Purple' verbena (Verbena canadensis Britton); ‘New Gold' lantana (Lantana camara L.).

Effects of Phosphorus Source, Phosphorus Rate, and Liming Rate on Growth and Quality of Verbena canadensis Britton ‘Homestead Purple’ and Lantana camara L. ‘New Gold’

Phosphate rock ores, rich in phosphorus (P), are mined in great quantities around the world for the production of P fertilizers. However, availability of phosphate reserves is in question due to decreasing global supplies. Therefore, application of alternative, renewable P sources is of interest. Poultry litter ash (PLA), a byproduct of bioenergy production, contains P concentrations comparable to conventional fertilizers. In this experiment, two P sources, PLA and superphosphate (SP), were compared at two P application rates and two liming rates as fertilizer sources for the production of two commonly-grown greenhouse crops (Verbena canadensis Britton ‘Homestead Purple’ and Lantana camara L.‘New Gold’). Application of PLA produced plants of comparable biomass and quality to those fertilized with SP. Increasing P application rate, across both P sources, increased total flower numbers 42 and 26% for verbena and lantana, respectively. Foliar P concentrations of verbena and lantana increased 27 and 62% for PLA-fertilized plants compared to SP. In addition, substrate pH increased 25% using PLA versus SP. Overall, PLA supplies adequate P fertility and does not reduce pH compared to the more water-soluble, rock phosphate based SP fertilizer.

Alternate host ranges of Cronartium flaccidum and Cronartium ribicola in northern Europe

Attached and detached leaves of 60 potential host species were inoculated in the greenhouse and laboratory with aeciospores of Cronartium ribicola J.C. Fisch. from six Finnish locations and of Cronartium flaccidum (Alb. & Schw.) Wint. from 20 locations in Finland and Sweden in 2011. Candidate hosts represented 16 plant families: Solanaceae, Verbenaceae, Asclepiadaceae, Grossulariaceae, Paeoniaceae, Balsaminaceae, Gentianaceae, Scrophulariaceae, Loasaceae, Tropaeolaceae, Acanthaceae, Myricaceae, Phrymaceae, Plantaginaceae, Orobanchaceae, and Apocynaceae. Inoculations of C. flaccidum produced uredinia after 2 weeks and (or) telia after 4 weeks of incubation on 25 hosts. Inoculation trials identified several new hosts for C. flaccidum in Fennoscandia, namely Impatiens balsamina, Swertia fedtschenkoana, Loasa tricolor, Myrica gale, Verbena canadensis, Saxifraga spp., Paeonia obovata, and Veronica daurica. Myricaceae and Saxifragaceae represent new host families for these rusts. Cronartium ribicola formed uredinia or telia on 10 species: Ribes spp. (7 species/cultivars), Pedicularis palustris subsp. palustris, Bartsia alpina, and Loasa triphylla. Results suggest wider alternate host ranges for both C. flaccidum and C. ribicola than previously recognized. Spores were virulent regardless of their source location, suggesting a lack of host-specificity among Fennoscandian populations of Cronartium.

Verbena canadensis Britt. Mutants with altered development of flowers and inflorescences generated by chemical mutagenesis

Rose vervain is a little-known ornamental annual plant. The adaptive properties (drought and cold resistance) and long period of flowering make this species promising for growing in flower gardens and containers. Chemical mutagenesis widely used for various plant species was applied to induce character variation in Rose vervain. The properties of development of flowers and inflorescences in lines descending from the M3--M5 mutants generated by the seed exposure to chemical mutagens diethyl sulfate and nitrosomethylurea were considered.

(213) Establishing Minimum Critical Nutrient Standards for Herbaceous Perennials

Herbaceous perennials comprise one of the fastest-growing segments of floriculture crop production. Little information has been published regarding their mineral nutrition requirements, specifically nutrient foliar standards and nutrient deficiency symptoms. Our research documents visual symptoms of nutrient deficiencies in the chronological order in which they appear from incipient to advanced stages, and establishes foliar analysis standards by correlating nutrient levels with initial and advanced stages of symptoms for nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, copper, zinc, manganese, molybdenum, and boron. Rooted cuttings were grown for as many as 12 weeks in a hydroponic system with modified Hoagland's solution minus the element of interest, along with complete nutrient solution controls. Taxa selected for study were representative of commonly grown varieties and of differing families; Verbena canadensis `Homestead Purple' (clump verbena), Heliopsis helianthoides `Bressingham Doubloon' (false sunflower) and Veronica × `Goodness Grows' (speedwell). Days to incipient deficiency symptoms ranged from 5 to 60. Chronological order of appearance was consistent with Fe and Ca symptoms appearing within 10 days for all three taxa. Other deficiency symptoms varied both by taxa and in chronology. Root and shoot dry weights were closely and positively correlated with time to incipient deficiency.

Responsible Plant Growth Recommendations from Greenhouse-grown Bedding Plant Experiments Must Integrate Data from Postharvest Landscape Evaluations

Multiple experiments conducted over the past 5 years suggest that greenhouse-grown bedding plants, particularly fall-propagated cool-season annuals, may exhibit reductions in vegetative growth and flowering in response to plant growth regulators (PGRs) applied at rates commonly used by growers. Studies using Viola ×wittrockiana Gams as a model system indicated that paclobutrazol applied at production stages and rates reportedly used by growers could result in significant postharvest residual responses that adversely impacted landscape performance. Most of these rates were also included within the recommended ranges on the agricultural chemical labels. Multiple applications to the same plants during production increased the severity of the residual responses and decreased the rates at which residual responses were detectable in landscape plantings. Tests with additional taxa, Brassica oleracea L. var. acephala DC, Calendula officinalis L., Ipomoea carnea Jacq. subsp. fistulosa (Mart. ex Choisy) D. Austin, Lantana urticoides Hayek `L.S. Red', Lupinus texensis Hook., Plumbago auriculata Lam., Salvia greggii Gray, and Verbena canadensis Kunth `Homestead Purple', PGR formulations and at various times of the year indicate that the postharvest landscape responses to PGRs vary among taxa and seasons. These results strongly suggest that in order for researchers to make responsible recommendations on PGR use, studies must include not only greenhouse or nursery production data, but also subsequent testing for residual responses to the PGRs in landscape settings.

A Virus Related to Clover Yellow Mosaic Virus Found East of the Mississippi River in Verbena canadensis in Florida.

In September 2002, several unthrifty Verbena canadensis 'Homestead purple' plants were received at the Division of Plant Industry in Gainesville, FL. Symptoms included very subtle yellowing and distortion or stunting of the younger leaves, symptoms that could be overlooked as a nutritional problem. Symptomatic leaves were ground in phosphate buffer and mechanically inoculated to a variety of plants that included Antirrhinum majus, Chenopodium amaranticolor, Datura stramonium, Gomphrena globosa, Pisum sativum, Trifolium pratense, T. repens, Vicia faba, and Vigna unguiculata. These hosts showed symptoms similar to those described for infection by Clover yellow mosaic virus (ClYMV) (3). In addition, the virus systemically infected Arachis hypogaea, Catharanthus roseus, C. quinoa, Nicotiana benthamiana, and healthy seed-grown Verbena × hybrida. No symptoms were seen in inoculated Zinnia elegans, N. glutinosa, N. clevelandii, Lycopersicon esculentum, Cucumis sativus, or Capsicum annuum. However, back inoculations of Cucumis sativus to C. amaranticolor gave typical local and systemic symptoms. Microscopic examination of leaf strips of infected V. faba revealed banded inclusions typical of the genus Potexvirus (1). Reverse-transcription polymerase chain reaction (RT-PCR) using degenerate primers for the genus Potexvirus (2) produced a 750-bp product that is the expected product for the genus Potexvirus. The RT-PCR product was cloned in pGem-T easy (Promega, Madison, WI) and sequenced. BLAST ( http://www.ncbi.nlm.nih.gov/ BLAST/ ) analysis of the sequence showed an 82% identity at the nucleotide level with the RNA polymerase gene of ClYMV. Leaf extracts of the original verbena, several inoculated hosts, and a known sample of ClYMV in N. benthamiana were tested in sodium dodecyl sulfate immunodiffusion (4) against antiserum to the degraded capsid protein of ClYMV. A reaction of identity was seen with infected samples but not with samples for comparable virus-free plants. To our knowledge, this is the first time this virus has been found in the eastern United States. It is not known how or if the presence of this noninsect transmitted virus in an ornamental will affect the agricultural, forage, or ornamental industries in the east or how widely distributed Verbena sp. infected with this virus may be at this time.

Accelerated Flowering of Herbaceous Perennials Under Nursery Conditions in the Southern United States

Abstract A study was conducted to determine the effects of night-interrupted (NI) lighting initiated at different times in late winter on several herbaceous perennials produced outdoors in a southern nursery setting. Treatments were NI lighting beginning February 1, February 15, March 1, March 15, and a natural photoperiod. NI lighting accelerated flowering in ‘Goldsturm’ coneflower (Rudbeckia fulgida Ait. ‘Goldsturm’) 26–46 days in 1999 and 51–75 days in 2000, and in ‘Coronation Gold’ yarrow (Achillea x ‘Coronation Gold’) 2–9 days in 1999 and 2–11 days in 2000. Flower and flower bud counts increased 82–100% in ‘Coronation Gold’ achillea in 1999, 44–51% in ‘Butterfly Blue’ scabious (Scabiosa columbaria L. ‘Butterfly Blue’) and 100–151% in ‘Alaska’ shasta daisy (Leucanthemum x superbum Bergmans ex. J. Ingram ‘Alaska’) compared to counts of plants under natural photoperiod. With few exceptions, plant height increased under all NI lighting treatments, but in only ‘Goldsturm’ coneflower did it reduce plant quality. Clump verbena (Verbena canadensis L.) was minimally affected by NI lighting, and speedwell (Veronica spicata L. ‘Sunny Border Blue’) was not affected at all.

Growth Regulation of Mexican Sage and ‘Homestead Purple’ Verbena During Greenhouse and Nursery Production

Abstract Salvia leucantha (Mexican sage) and Verbena canadensis ‘Homestead Purple’ were treated with the plant growth retardants (PGRs), Cutless, Sumagic, B-Nine/Cycocel tank mixes, or Pistill under both greenhouse and nursery conditions. Increasing rates of all PGRs applied to both species reduced plant size in the greenhouse for 6 weeks after treatment (WAT). Growth reduction of Mexican sage with the most effective rate (providing greatest growth control) of each PGR over this period averaged 11% with Cutless, 15% with Sumagic, 23% with B-Nine/Cycocel tank mixes, and 25% with Pistill. For verbena, size control with the most effective rate of each PGR averaged 15% with Cutless, 18% with Sumagic, 27% with B-Nine/Cycocel tank mixes, and 29% with Pistill. After transplanting greenhouse-grown plants into outdoor ground beds, only Mexican sage treated with B-Nine/Cycocel were significantly smaller 4 weeks after planting (WAP). Greenhouse-grown verbena treated with Sumagic, B-Nine/Cycocel tank mixes, and Pistill and planted in the landscape were 15—23%, 18–25%, and 0–20% smaller, respectively, than control plants at 2 WAP, but by 4 WAP, all PGR-treated verbena were similar in size to control plants. Under nursery conditions, Cutless and B-Nine/Cycocel tank mix reduced Mexican sage size up to 4 WAT. None of the PGRs affected plant size at 6 WAT. The most effective rate of each PGR (averaged over the duration that a PGR was significant) suppressed shoot growth 16% for Cutless, 12% with Sumagic, 20% for B-Nine/Cycocel tank mixes, and 29% for Pistill. For verbena only, Sumagic suppressed growth up to 10% at 2 WAT, and no PGR effectively controlled growth under nursery conditions 4 WAT.

Oklahoma Proven—A Statewide Marketing and Evaluation Program

Oklahoma Proven (OKP) is a plant promotion and evaluation program designed to help consumers choose plants appropriate for Oklahoma gardens. Aiding consumers with plant selection will lead to greater gardening success, enthusiasm, and increased sales for Oklahoma green industries. There are two major facets to the program: marketing, coordinated by Dr. Lou Anella, and evaluation, coordinated by Dr. Michael Schnelle. Plants to be promoted by OKP will be selected by an OKP executive committee based on recommendations from an OKP advisory committee comprised of industry professionals, cooperative extension specialists and educators, Oklahoma Botanical Garden and Arboretum affiliate members, and Department of Horticulture and Landscape Architecture faculty. Plants chosen for OKP must meet the following selection criteria: appropriate for gardens throughout the state of Oklahoma; readily available in the trade; limited input required, i.e. few pest or disease problems, tolerant of Oklahoma's diverse soil types and weather conditions; noninvasive; can be profitably produced. The OKP Advisory Board selected the following OKP Selections for 2000: Taxodium distichum; Spiraea japonica `Magic Carpet'; Verbena canadensis `Homestead Purple'; and Scaevola aemula. Promotional materials, such as posters and signs, will be available just after the first of the year, and the promotional push will begin in early March. Posters and signs will be distributed to retailers throughout the state free-of-charge and pot stakes and hang tags will be sold to wholesalers as a means of generating income for the Oklahoma Proven program. OKP plants will also be promoted through the television show “Oklahoma Gardening,” extension newsletters, and the press.

Environmental Modifications of Leaf Epidermis and Morphological Features in Verbena canadensis

Environmental Modifications of Leaf Epidermis and Morphological Features in Verbena canadensis

THE KNOWN GEOGRAPHIC DISTRIBUTION OF THE MEMBERS OF THE VERBENACEAE AND AVICENNIACEAE: SUPPLEMENT 4

OVER 3800 additional herbarium specimens of Verbenaceae and Avicenniaceae have been examined by the writer since the preparation of the last supplement to his listing of the known geographic distribution of the 2980 valid members of these two plant families based on an examination of 75,000 specimens.2 This additional material has come from the herbaria of the New York Botanical Garden, Trinidad and Tobago Botanical Garden, United States National Museum, Instituto Ciencias Naturales at Bogota, Butler University, Duke University, West Virginia University, Arnold Arboretum, Carnegie Museum, Kansas State College, Colorado State College, Pomona College, Georgia Agricultural Experiment Station, and numerous individual collectors, including Dr. H. Hapeman at Minden, Nebraska. It has yielded the following 53 new country or island records, 34 state or province records, and 141 county records. One new species and one new combination are proposed. NEW YORK: Phyla lanceolata (Michx.) Greene -Onondaga County. Verbena hastata L.-Erie County. Verbena urticifolia L.-Suffolk County. PENNSYLVANIA: Phyla lanceolata (Michx.) Greene-Butler County. Verbena canadensis (L.) Britton-Washington County. X Verbena Engelmannii Moldenke-Crawford and Delaware Counties. Verbena hastata L.-Allegheny, Beaver, Blair, Clarion, Crawford, Elk, Forest, Indiana, Jefferson, McKean, Mercer, Potter, Somerset, Tioga, Union, and Venango Counties. Verbena hastata f. rosea Cheney-Huntingdon County. Verbena simplex Lehm.-Bedford, Erie, and Fulton Counties. Verbena stricta Vent.-Allegheny, Erie, and Westmoreland Counties. Verbena urticifolia L.-Beaver, Bedford, Bradford, Butler, Cambria, Centre, Clarion, Clearfield, Lawrence, Pike, and Westmoreland Counties. Verbena urticifolia var. leiocarpa Perry & Fernald-Clearfield, Greene, Lawrence, Northampton, Washington, Wayne, and Westmoreland Counties. MARYLAND: Phyla lanceolata (Michx.) Greene -Washington County. WEST VIRGINIA: Verbena hastata L.-Cabell, Kanawha, and Raleigh Counties. Verbena simplex Lehm.-Kanawha County. Verbena urticifolia L.Marion County. Verbena urticifolia var. leiocarpa Perry & Fernald-Barbour and RandolphWCounties.