bluuebunny/crossref_metadata_2025 huggingface dataset:
Epicormic Shoot Forcing of Adult Red Maple, Sugar Maple, and Eastern Black Walnut
Authors: Connolly David A. , Bailey Amy B. , Preece John E. , Van Sambeek J.W.
Published: February 2019

Dormant stem sections from three individuals each of Acer rubrum (red maple) and A. saccharium (sugar maple), and three clones of Juglans nigra (eastern black walnut) were collected from lower lateral branches of trees at least 30 years old. The stem sections were cut into 50-cm-long segments and placed horizontally in soilless media in a greenhouse. Two experiments were conducted to determine which treatments were most efficient for the production and elongation of epicormic shoots from latent buds below the bark. The first experiment consisted of a factorial arrangement of two levels of shading (not shaded or covered with 48% Saran shade cloth) and two levels of flooding (not flooded or flooded to a depth of 1/3 to 1/2 the diameter of the stem sections). Flooded treatments contained 0.025% NaClO to control microbial growth. The second experiment consisted of three media treatments: perlite, vermiculite, or a 1 perlite: 1 vermiculite (by volume) medium. No stem segments of any species in flooded treatments produced softwood shoots. Neither shading nor media treatments affected shoot number or length for any of the species. Additional sugar maple segments collected after budbreak produced more and longer shoots than those collected while dormant.
Axillary Shoot Proliferation of Adult Eastern Black Walnut
Authors: Bailey Amy B. , Preece John E. , Van Sambeek J.W.
Published: February 2019

Softwood shoots of adult Juglans nigra (eastern black walnut) were forced from latent (epicormic) buds below the bark of large stem sections in a greenhouse. Once sufficiently long, the shoots were excised, surface-disinfested, and cut into 1-cm-long nodal or apical segments for establishment in culture vessels. Two experiments were conducted, each using explants of three different clones. The first experiment compared the effect of cytokinins: 0.3, 1.0, or 3.0 μM benzyladenine (BA) and 0.1, 0.3, or 1.0 μM thidiazuron (TDZ) arranged factorially. The basal medium was agar-solidified Long and Preece (LP) with 0.05 μM indole-3-butyric acid (IBA) and 30 g/L sucrose. The second experiment compared the agar-solidified basal media: Driver-Kuniyuki-Walnut (DKW), Woody Plant Medium (WPM) and LP, all with 1.0 μM BA, 0.3 μM TDZ, 0.05 μM IBA, and 30 g/L sucrose. Regardless of the BA concentration, explants on media containing 0.1 μM TDZ produced few, if any, axillary shoots while explants on media containing 1.0 μM TDZ excessive amounts of callus. Explants in media containing 0.3 μM TDZ, at all levels of BA, produced the greatest number of shoots and minimal callus. Male catkins were produced by 17 explants on various media. Fifteen of the catkin-producing explants were from one walnut clone. Axillary shoot number and callus production were not significantly affected by basal medium for any of the three clones.
Inflorescence Removal Effects on Root Yield of American Ginseng (Panax quiquefolium L.)
Authors: Proctor J.T.A. , Percival D.C. , Louttit D.
Published: February 2019

American ginseng is a perennial herbaceous plant grown for its fleshy root and seeds. Little is known about fruit set and development in ginseng. In commercial practice a small proportion of 2-year-old plants may bear flowers and seed but these seeds usually are not harvested. Seeds from 3-year-old plants are harvested and used for establishing plantings, but seed from 4-year-old plants, if available, are preferred. Some growers remove flowers manually from plants in June at an estimated cost of $2500 per ha and claim higher root yields. The objective of this work was to determine the effect of inflorescence removal in 1 or 2 years on root yield. Manual removal of inflorescences from mature (3-and 4-year old) American ginseng plants at commercial timing (early July, ≈25% flowers open) increased root yield at harvest compared to plants where the inflorescences were retained. Consecutive inflorescence removal for 2 years (3rd and 4th) increased yields 55.6% compared to 34.4% for removal in one year only (4th). Root size distribution analysis showed that most roots (≈40%) were in the medium category (10–20g): inflorescence removal did not influence root size distribution. Root yield for 3-year-old plants increased quadratically with plant density with plants lacking inflorescences having an estimated yield increase of 25%. Maximum yields of 2.4 kg·m–2 for deflowered plants were suggested at a plant density of 170 plants/m2. To maximize ginseng root yield all plants should have inflorescences removed except those needed to provide seed for future plantings.
Soybean Oil Used as an Alternative Pesticide on Nursery Stock
Authors: Lancaster A.L. , Deyton D.E. , Sams C.E. , Pless C.D. , Fare D.C. , Moran R.E. , Cummins J.C.
Published: February 2019

Research was conducted to determine if soybean oil sprays may substitute for petroleum oil for control of insects on nursery crops. Dormant field-grown `Globe' arborvitae shrubs infested with Fletcher scale were sprayed on 9 Mar. 1997 with 0%, 2%, 3%, or 4% soybean oil. One hundred scales per plant were evaluated on 4 Apr. 1997. Spraying 2% to 4% soybean oil on dormant arborvitae caused ≥97% mortality of Fletcher scale compared to only 7% mortality on untreated plants. of white pine, viburnum, `Anthony Waterer' spirea, `Green Beauty' boxwood, western red cedar, `Blue Star' juniper, `Blue Pacific' juniper, `Japanese Garden' juniper, and arborvitae plants in trade gallon pots and `Densiformus' yew and dwarf `Alberta' spruce in trade quart pots were sprayed with 0% (water control), 1%, or 2% soybean oil (emulsified with Latron B-1956) or 2% SunSpray Ultra-Fine Spray oil on 26 Aug. 1997 for phytotoxicity evaluation. No phytotoxicity occurred on western cedar, spirea, boxwood, yew, arborvitae, or viburnum. Spraying Sunspray or soybean oil caused initial loss of blue color on blue junipers and white pine. Spraying 1 or 2% soybean oil or 2% SunSpray caused phytotoxicity to `Blue Star' juniper. The `Blue Pacific' juniper, `Japanese Garden' juniper, and Alberta spruce were slightly damaged by 2% but not by 1% soybean oil.
The Relationship Among Storage Condition and Seed Moisture Content Revisited
Authors: Fang Jian , Moore Frank , Roos Eric E. , Walters Christina
Published: February 2019

Seed moisture content (MC) changes depending upon relative humidity (RH) and temperature (T). This relationship was revealed by studying the interaction of RH and T at equilibrium. Maize, cucumber, onion, lettuce, watermelon, and pea seeds were equilibrated over various saturated salt solutions (1% to 93% RH) at temperatures from 5 to 50 °C. Five-hundred-eleven subset models were selected from a complete third-order model MC = 0 + 1*RH + 2*T + 3*RH2 + 4*T2 + 5*RH*T + 6*RH3 + 7*T3 + 8*RH*T2 + 9*RH2*T using Mallows' minimum Cp as the selection criterion. All six best subset models were found to have the same functional form, MC0 + 1 = *RH + 2*T + *RH2 + 5*RH*T + 6*RH + 9*RH2*T. Coefficients had essentially the same respective values among species, except for the onion and pea models (P ≤ 0.05). All models indicated that seed MC increased as RH increased and decreased as temperature increased. A previous paper (Vertucci and Roos, 1990) indicated that optimum RH for orthodox seed storage is between 19% and 27%. Using these models, the range for the optimum moisture content for storage of most orthodox seeds can be quickly calculated for any given storage temperature.
Effects of Trichoderma harzianum Strain T-22 Sprays on Incidence of Sooty Blotch and Fly Speck of Apple and Botrytis Fruit Rot of Raspberry
Authors: Kiyomoto Richard K.
Published: February 2019

Tests were made to determine the effectiveness of Trichoderma harzianum T-22 sprays in controlling sooty blotch (Zygophiala jamaicensis) and fly speck (Gloeodes pomigena) in five experimental scab-resistant apple varieties and botrytis fruit rot in five fall-bearing red raspberry cultivars. T-22 and S-12 surfactant used in these studies were supplied by BioWorks, Inc., Geneva, N.Y. Treatments applied to runoff on foliage and fruit were: unsprayed; T22 (1.2 g·L–1), T22 + S-12 (1.2 g·L–1 + 0.5 g·L–1), Captan 50W +T22 (1.2 g·L–1 + 1.2 g·L–1), and Captan 50W (1.1 g·L–1). Raspberry treatments substituted Rovral for Captaon 50W. Cultivars in the apple and raspberry trials were planted in a randomized complete block design with three blocks in the apple and four blocks in the raspberry planting. All spray treatments were applied to each cultivar in a block. Apples were treated on 5 Aug., 19 Aug, 2 Sept., and 16 Sept. and fruit were evaluated as cultivars ripened from 29 Sept. to 17 Oct. Raspberries were treated on 30 July (34% to 86% bloom), 14 Aug., 28, Aug., and 9 Sept. Evaluation for Botrytis was made throughout this period and data are presented for 12 Sept. Incidence of sooty blotch and flyspeck were ≈50% lower in T22 treatments than in unsprayed controls, but the difference was not significant. Captan treatments had significantly lower incidence of sooty blotch. Captan and T22 treatments had less flyspeck than the unsprayed controls, but the differences were not significant. Significant cultivar × treatment interactions may have resulted from the prolonged evaluation period and obscured differences in treatment effects In the fall raspberries 10% of untreated, 5% of T22 and T22 + S-12-treated, and 2% of Rovral and Rovral + T22 fruit were infected with Botrytis. These differences were highly significant.
Bioremediation of Greenhouse Effluent using Constructed Wetlands
Authors: Meche Michelle S. , Lang Harvey J. , Kenimer Ann L.
Published: February 2019

Due to problems of water shortages and increased legal constraints concerning effluent content, nursery and greenhouse operations are in need of new methods of cleaning and reusing irrigation water. Using constructed wetlands to improve water quality is a low-cost and rapidly emerging ecotechnology, and is currently used for treating wastewater from cattle operations, catfish ponds, and residential subdivisions. To examine the effectiveness of constructed wetlands, a greenhouse was equipped with five free-standing wetland cells planted with Equisetum hyemale (Horsetail). Cells consisted of 0.9 × 2.4-m metal tanks filled with pea gravel (about 0.7 m deep) with inlet and outlet sampling ports. Each cell collected runoff from individual greenhouse benches stocked with impatiens or marigolds grown in pots containing Sunshine LC1 media and fertigated using trickle irrigation. Runoff flow rates and volume entering each cell were measured. Water samples were taken 1) directly from the irrigation line, 2) as bench crop runoff, 3) after entering the cell, and 4) after exiting the cell, and were analyzed for various N fractions. Preliminary studies indicated that the cell size used in these studies was sufficient to handle runoff volume from each bench and could reduce overall N concentration in the runoff. There was significant variability in effectiveness between the cells, which appears to be due to differences in cell vegetation growth and establishment. Overall evaluation of the system and recommendations will be discussed.
Crop Residues in San Joaquin Valley Row Crop Systems
Authors: Mitchell J.P. , Hartz T.K. , Pettygrove G.S. , Munk D.S. , May D.M.
Published: February 2019

The West Side of California's San Joaquin Valley is one of the most productive agricultural regions of the world. The leading crops of this region include processing tomatoes, cotton, onions, garlic, cantaloupes, and lettuce, which are grown on over 570,000 acres annually. During the past 30 years, land use patterns on the West Side have changed considerably. More than 60% of the acreage in this area was typically planted to wheat, barley, and safflower in 1965, whereas in 1994 these crops were grown on 7% of the area. The intensification in the production of high value crops has led to fewer additions of organic matter to the soil and more aggressive tillage operations. In 1996–97, we quantified the amount and composition of postharvest crop residues that are returned to the soil in typical West Side rotations. The highest amount of crop residues resulted from corn stubble following grain harvest (10,300 lb dry matter per acre) and the lowest amounts resulted from onions and garlic, with 517 and 700 lb dry matter per acre, respectively. These data demonstrate the large range of organic matter recycling that results from varous intensive cropping strategies in this region.
Yield and Nutrient Uptake of Peppers (Capsicum annuum) Grown with Dairy Manure Compost and Fertigated Nitrogen
Authors: Roe Nancy E.
Published: February 2019

The use of compost as an organic source of nutrients and soil improvement may help to increase the sustainability of intensively managed vegetables. Bell pepper (Capsicum annuum L.) transplants were planted into silver-colored polyethylene mulched beds in a sandy loam soil amended with 0 or 22.4 Mg·ha–1 dairy manure compost. Preplant P was added to all beds at 78 kg·ha–1. During the season, N (as NH4NO3) was added about every 10 days. Total N rates for the season were: 0, 32, 65, or 96 kg·ha–1. Percent of N in pepper leaf tissue increased from a low of 2.7% without N to3.8% at the high N rate. Leaf P concentrations were higher in 0 N plots than in other rates. Compost resulted in higher leaf concentrations of Ca. There was an interaction of compost and N rates for percent of culls. Compost increased percentage of culls with 0 or 32 kg·ha–1 N, but decreased or did not affect cull percentage at 65, or 96 kg·ha–1 N. Compost did not affect other yield parameters measured. Marketable yields increased from 11 Mg·ha–1 with 0 N to 18 Mg·ha–1 with high N, although the regression was not significant, due to extreme variability within the field.
Urea Combined with 6-Benzyladenine Applied to the Foliage of Pistachio Trees during Nut-fill Reduced Floral Bud Abscission during the “On” Crop Year and Increased Yield the Following “Off” Crop Year
Authors: Daoudi Hassania , Ferguson Louise , Lovatt Carol J.
Published: February 2019

Alternate bearing of pistachio (Pistacia vera L. cv. Kerman) is a significant problem in California. Excessive abscission of floral buds beginning in June and intensifying at the time of seed development (nut-fill) in July during the “on” year results in the next year's “off” crop. While the mechanism resulting in alternate bearing in pistachio has been identified, its physiological basis has not and there is no satisfactory horticultural practice to even out alternate bearing. Bud retention in pistachio was increased 3-fold and 2-fold for two successive years, respectively, on branches bearing greater than 70 nuts per cluster (an “on” crop) basal to the shoot bearing the buds for next year's crop with foliar applications of 0.25% N as low-biuret urea combined with 25 mg 6-benzyladenine per liter applied in early June and early July. In Sept. 1997, the crop produced by the buds treated in 1996, an “on” crop year, was harvested. The untreated control trees produced an “off” crop, 7.6 kg fruit per tree, yielding 0.5 tons split nuts (dry weight) per acre. Trees treated with 0.25% N as urea combined with 25 mg 6-benzyladenine per liter on June 1 and July 1 yielded 16.4 kg fruit per tree, resulting in 1.14 tons split nuts (dry weight) per acre (P ≤ 0.05).
Effect of Growth Regulators on Rooting of Magnolia grandifloraCultivars
Authors: Jiang Ning , Zhang Donglin , Dirr Michael A.
Published: February 2019

Cuttings from three southern magnolia cultivars, `Claudia Wannamaker', `Greenback™', and `Little Gem', were treated with KIBA, KNAA, and Hormodin #3, separately and in combination, at varying concentrations. The rooting of cuttings was cultivar-dependent, with `Greenback™' responding significantly to all the treatments. Only the high KNAA and combination treatments were effective with `Little Gem' and `Claudia Wannamaker'. The effect of KNAA on rooting with increasing concentration was significant. No similar response was observed with KIBA. The combination treatment with quick dip plus the talc formation produced the greatest rooting and root quality with the three cultivars. With this treatment, the average rooting rate of three cultivars was 67.4%, whereas the rooting rate of control plants was only 11.8%.
Propagation of Thuja × `Green Giant' by Stem Cuttings: Effects of Growth Stage, Type of Cutting, and IBA Treatment
Authors: Griffin Jason J. , Blazich Frank A. , Ranney Thomas G.
Published: February 2019

Stem cuttings of Thuja L. × `Green Giant', consisting of 22-cm terminals or 20-cm laterals, were collected on three dates associated with specific growth stages (softwood, semi-hardwood, and hardwood), and treated with indolebutyric acid (IBA) in 50% isopropanol ranging from 0 to 9000 ppm and placed under intermittent mist. Regardless of cutting type or auxin treatment, cuttings rooted in high percentages at each growth stage. Overall rooting was highest for hardwood cuttings (96%) followed by semi-hardwood (86%), and softwood (85%) cuttings. Semi-hardwood cuttings were the only cuttings in which rooting was affected by IBA or cutting type with the greatest rooting (94%) attained using lateral cuttings treated with 6000 or 9000 ppm IBA. Although an interaction occurred between IBA treatment and cutting type for mean root length of hardwood cuttings, only mean root length of semi-hardwood cuttings was influenced by IBA concentration alone with the greatest length (25 mm) achieved with 6000 ppm IBA. An interaction was noted for root count between cutting type and IBA concentrations for softwood cuttings, whereas IBA and cutting type affected independently root count on semi-hardwood cuttings. Treatment with 9000 ppm IBA resulted in 18 roots per rooted cutting whereas lateral cuttings responded with a mean of 16 roots over all IBA concentrations. Root count on hardwood cuttings was affected by IBA treatment only, with 9000 ppm being optimum (14 roots per rooted cutting).
Plant Biotechnology Workshop for High School Students
Authors: Szendrak Erika , Read Paul E. , Miller Jon S.
Published: February 2019

Modern aspects of many subjects (e.g., computer science and some aspects of medical science) are now taught in many high schools, but the plant sciences are often given short shrift. A collaboration was therefore established with a high school biology program in which pilot workshops could be developed to enable advanced students to gain insights into modern plant science techniques. A successful example is the workshop on plant biotechnology presented in this report. This workshop is simple and flexible, taking into account that most high school biology laboratories and classrooms are not set up for sophisticated plant science/biotechnology projects. It is suitable for from 10 to 30 students, depending upon space and facilities available. Students work in pairs or trios, and learn simple disinfestation and transfer techniques for micropropagation and potential subsequent transformation treatments. Students gain insights into: sterile technique and hygiene; plant hormones and their physiological effects; plant cell, tissue and organ culture; the influence of environmental factors on response of cells and tissues cultured in vitro; and an understanding of the phenomenon of organogenesis and resulting plant growth and development. This workshop has been tested on several classes of students and following analysis, several refinements were included in subsequent iterations. Results of the students' experiments have been positive and instructive, with student learning outcomes above expectations. Further details of the workshop techniques and approach will be presented.
Identification of Tsuga Species Hybrids Using Molecular Markers
Authors: Pooler Margaret R. , Bentz Susan E. , Townsend Alden M. , Deming Clayton B.
Published: February 2019

In both urban and rural areas, landscape and forest settings, the eastern hemlocks (Tsuga canadensis and T. caroliniana) are suffering major damage and mortality from the hemlock woolly adelgid (Adelges tsugae). Research efforts at the U.S. National Arboretum are focusing on the development of resistant hybrids by crossing the East coast native species with the Asian species T. chinensis, T. diversifolia, and T. seiboldii, which are reported to be more tolerant to damage by the woolly adelgid. More than 2000 seedlings have resulted from these crosses and controls. However, positive identification of these putative hybrids cannot easily be made based on visual inspections due to variation in morphological traits. We are using molecular markers, including RAPD-PCR and Sequence Characterized Amplified Regions (SCARs) to screen putative hybrids. Our data indicate that RAPD bands are useful to analyze the variation within a particular cross, but are of limited use in identifying hybrids. The development of SCARs enables fast and accurate identification of hybrids using only three to four leaves from a seedling. The production of hybrids among these five species will generate novel combinations of genes for studying adaptability, pest resistance, and horticultural attributes, as well as broaden the genetic base of cultivated hemlocks.
Preliminary Investigation on Discrimination and Genetic Diversity of Cephalotaxus Taxa Using AFLP Markers
Authors: Zhang Donglin , Dirr Michael A. , Price Robert A. , Kresovich Stephen , Mitchell Sharon
Published: February 2019

Cephalotaxus species and cultivars have become popular because of their sun and shade tolerance, resistance to deer browsing, disease and insect tolerance, and cold and heat adaptability. Unfortunately, the nomenclature and classification in the literature and nursery trade are confusing due to their extreme similarity in morphology. To address this problem, a preliminary investigation utilizing the AFLP technique was applied to taxon discrimination and genetic difference among 90 Cephalotaxus accessions. A total of 403 useful markers between 75- and 500-bp fragment sizes was generated from three primer-pair combinations. The clustering results with reference to morphological characteristics showed that 79 accessions out of 90 can be classified as three species, C. oliveri Mast., C. fortunei Hook., and C. harringtonia (Forbes) Koch., and one hybrid species, C. × sinensis; four varieties, C. fortunei var. alpina, C. harringtonia var. koreana, C. harringtonia var. nana, and C. harringtonia var. wilsoniana; and eight cultivars. Suggested names are provided for mislabeled or misidentified taxa. The Cephalotaxus AFLP data serve not only as a guide to growers for the identification and genetic differences of a taxon, but also as a model to establish a “cultivar library” against which later introductions or problematic collections can be cross-referenced.
Eliminating Thrips in Microshoot Cultures
Authors: Tripepi Robert R. , Schwager Holly J. , George Mary W. , McCaffrey Joseph P.
Published: February 2019

Two insecticides, acephate or azadirachtin, were added to tissue culture media to determine their effectiveness in controlling onion thrips (Thrips tabaci Lindeman.) and to determine if these insecticides could damage the plant shoot cultures. To test for insecticide phytotoxicity, microshoots from European birch (Betula pendula), American elm (Ulmus americana), `Pink Arola' chrysanthemum (Dendranthema grandiflora), `America' rhododendron (Rhododendron catawbiense), `Golden Emblem' rose (Rosa hybrida), and `Gala' apple (Malus domestica) were placed in 130-ml baby food jars containing 25 ml of medium supplemented with 6.5, 13, or 26 mg/l Orthene® (contained acephate) or 0.55, 1.1, or 2.2 ml/l Azatin® (contained azadirachtin). Control jars lacked insecticide. To test for thrips control, 13 mg/l Orthene® or 0.55 ml/l Azatin® was added to Murashige and Skoog medium, and 10 thrips were placed on `Gala' apple microshoots in each jar. Jars were sealed with plastic wrap. In both studies, microshoot dry weight and heights were determined. In the second study, the total number of thrips per jar was also determined 3 weeks after inoculation. Microshoots on Orthene®-treated media lacked phytotoxicity symptoms, regardless of the concentration used. In contrast, Azatin® hindered plant growth, decreasing shoot height or dry weight by up to 85% depending on the species. Both insecticides prevented thrips populations from increasing, since less than 10 thrips were found in jars with insecticide-treated medium. Control jars, however, contained an average of almost 70 thrips per jar. This study demonstrated that both Orthene® and Azatin® were effective for eradicating thrips from plant tissue cultures, but Orthene® should probably be used because Azatin® was phytotoxic to all species tested.
Extension Program Delivery for Greenhouse Growers Using Compressed Video Technology
Authors: Newman Steven E. , Panter Karen L.
Published: February 2019

There is a need for educational programming for greenhouse growers on effective uses of biorational pesticides and biological controls of insect and mite pests, diseases, and alternatives to herbicide sprays in confined areas; however, in many states, travel for specialists for programming and workshops is becoming prohibitive. A series of programs outlining Best Management Practices (BMP) for the greenhouse industry outlining techniques and practices reducing pesticide use were conducted at multiple sites in Colorado simultaneously using interactive compressed video technology. This conferencing technology is gaining wide acceptance in many venues and provides an opportunity for wider participation of clientele without travel. Participants in the programs reported in post-session evaluations that they did miss the personal interaction with the speakers, but did acknowledge that not having to drive 5 hours to attend a seminar was quite beneficial.
Vernalization Accelerates Flowering of Lysimachia clethroides Duby
Authors: Lewis Pamela M. , Armitage Alan M. , Garner Jim M.
Published: February 2019

The effect of vernalization method and duration on off-season cut flower production of Lysimachia clethroides Duby was examined. Rhizomes harvested in October were cooled for 0, 4, 6, 8, 10 or 12 weeks at 4 ± 1 °C in crates with unmilled sphagnum peat or in 3.75-L pots with potting media prior to forcing in a warm greenhouse. After 6 or more weeks of cooling, shoots emerged from crate-cooled rhizomes in higher percentages than from pot-cooled rhizomes. However, only the duration of cooling, not the method, affected the rate of shoot emergence, visible bud formation and anthesis of the first bud in the raceme. As cooling increased from 0 to 12 weeks, the greenhouse days required for shoot emergence, visible bud formation and anthesis decreased linearly. The number of flowering flushes and flowering stems varied quadratically with cooling duration, and the highest yields occurred when rhizomes received between 4 and 10 weeks of cooling. As the number of successive flowering flushes increased, the stem length increased linearly while the stem diameter decreased linearly. High numbers of flowers were produced rapidly after 10 weeks of cooling.
Photoperiod and Temperature Influence on Flower Initiation and Development for Euphorbia pulcherrima Grown Under Florida Conditions
Authors: Wieland C.E. , Barrett J.E. , Clark D.G. , Wilfret G. J.
Published: February 2019

Four poinsettia cultivars were grown in glass greenhouses in Gainesville, Fla., in the Fall 1997 to evaluate differences in floral initiation and subsequent development. Three means of regulating photoperiod were 1) natural days 2) long-day lighting to 6 Oct. and then natural days (lights out) 3) long-day lighting to 6 Oct., and then short-day conditions by black cloth for 15 h (black cloth). At 2-day intervals, sample meristems were collected and examined for initiation of reproductive development. Average minimum and maximum temperatures during the first two weeks of October were 22 and 29 °C, respectively, with an average temperature of 25.3 °C. The overall average temperature was 23.2 °C from planting to anthesis. Differences in anthesis dates among cultivars were primarily due to time to initiation vs. rate of development. Under natural days, `Lilo' initiated first on 8 Oct. and `Freedom', `Peterstar', and `Success', followed by 6, 8, and 18 days, respectively. Lights out resulted in `Lilo' initiating 17 Oct., followed by `Freedom', `Peterstar', and `Success' initiating 7, 12, and 15 days later, respectively. Differences between cultivars in time of initiation was reduced under black cloth, where `Lilo' initiated 14 Oct., followed by `Freedom' 2 days later, and `Peterstar' and `Success' 7 days afterward. Initiation was positively correlated to visible bud and anthesis. First color was positively correlated to initiation and visible bud, with the exception of `Lilo'. Growth room studies conducted using various high temperatures and photoperiods indicated similar trends.
Using Extended Field Trips to Enhance the Undergraduate Experience
Authors: McDuffie Robert F.
Published: February 2019

While the use of field trips is not new to undergraduate education, tailoring a 3- to 4-day field experience to enhance classroom instruction is challenging, but rewarding, for students, faculty, and alumni. Drawing on alumni in the private and public sectors to serve as guides has added significantly to the experience and has strengthened alumni ties to the department. Problems associated with extended field trips, such as those related to behavior and legal liabilities, can often be avoided by proper scheduling and insurance planning. Funding can be augmented by an industry eager to find qualified graduates.
Fumigation of `Flame Seedless' Grape With E-2-Hexenal Reduces Mold during Long-term Cold Storage
Authors: Archbold Douglas D. , Hamilton-Kemp Thomas R. , Clements Ann M. , Collins Randall W.
Published: February 2019

`Flame Seedless' grapes were fumigated with vapor of E-2-hexenal to determine if the compound could reduce mold during long-term cold storage. The compound (100 or 200 μL) was placed in 1-L low-density film-wrapped clamshell containers with 150 g of fruit, and the packages were stored at 2 °C. The packages were vented at 4 and 8 weeks to prevent excessive oxygen depletion or carbon dioxide accumulation. At 2, 4, and 8 weeks, a subset of packages were removed from cold storage and transferred to 20 °C following removal of the over-wrapped film and remaining chemical from the containers. Mold development and quality changes were assessed for the subsequent 13 days. The vapor phase concentration of E-2-hexenal was at a maximum within 1 day and declined to less than 25% of initial levels by 2 weeks of 2 °C storage. The higher volume of chemical resulted in a higher headspace concentration, and the fruit removed a proportion of the chemical from the headspace. There were no significant effects of E-2-hexenal on fruit weight loss, firmness, or total soluble solids concentration. After 2 weeks of cold storage, fumigation with E-2-hexenal had no effect on incidence of mold. However, after 4 and 8 weeks of cold storage, mold was significantly reduced by both rates of E-2-hexenal.
Rate of Fertilizer Application and Pot-in-Pot Production Increase Growth of Heritage River Birch
Authors: Ruter John M.
Published: February 2019

A study was conducted to compare the effects of three rates of fertilizer (High N–Southern Formula, 23N–1.7P–6.6K at 1.3, 1.7, and 2.0 kg N/m3) and two production systems [pot-in-pot (PIP) or conventional above-ground (CAG)] on the growth of Heritage river birch (Betula nigra L. `Cully') in 26 L (#7) containers. Plants grown PIP had higher shoot dry weight (20%), root dry weight (31%), total biomass (27%) and root:shoot ratios (12%). Fertilizer rate increased shoot dry weights but decreased root:shoot ratios. Rate of fertilizer application influenced foliar Mg, Zn, and Fe while production system had no effect. The foliar P:Zn ratio increased linearly as rate of fertilizer increased. Soluble salts and NO3-N in the leachate increased linearly as rate of fertilizer increased at 15 and 60 days after application (DAA), whereas the response was curvilinear at 120 DAA. When different, nutrient concentrations in the leachate were greater for plants grown CAG. Fertilizer longevity was greater when the PIP system was used, presumably due to lower substrate temperatures during the experiment period.
Response of Dehydrins to Drought, Low Temperature, and ABA Treatment in Whole Plants and Cell Suspension Cultures of Blueberry
Authors: Panta G.R. , Parmentier C.M. , Rowland L.J.
Published: February 2019

Previously, three dehydrins of 65, 60, and 14 kDa were identified as the predominant proteins present in cold-acclimated blueberry floral buds. Levels were shown to increase with cold acclimation and decrease with deacclimation and resumption of growth. Recently, a dehydrin cDNA clone was isolated and sequenced, and shown to hybridize to messages likely to encode all three dehydrins. In the present study, expression of dehydrins was examined in blueberry cultivars in response to drought and low-temperature treatment and in cell suspension cultures in response to low temperature and ABA treatment. During 32 days of drought stress, relative shoot water content dropped to 51% to 90%, depending upon cultivars. For cold stress experiments, cultivars with different chilling requirements and levels of cold hardiness were kept at 4 °C for 5 weeks. Cell suspension cultures were held at 4 °C for up to 2 weeks. For ABA experiment, ABA concentrations ranging from 10-3 to 10-7 M were used. Dehydrins were monitored in response to various treatments at RNA and proteins levels using the cDNA clone and antisera raised against the dehydrins. Interestingly, a previously uncharacterized 30 kDa dehydrin was found to be the major low temperature and ABA-responsive protein in cell suspension cultures.
Changes in Responsiveness to Ethylene at the Molecular Level during Carnation Petal Development
Authors: Verlinden Sven , Woodson William R.
Published: February 2019

Differences in responsiveness and sensitivity to plant hormones between tissues and in specific tissues during development have been observed. Increased sensitivity to ethylene during development has been demonstrated in fruits and flowers. In order to study the molecular changes in responsiveness to ethylene during flower development carnation petals of three developmental stages were treated with 0.1, 1, 10, 100, pr 1000 ppm of ethylene for 0, 0.5, 1, 3, 6, 9, 15, or 24 h. Northern blot analysis was performed on total RNA extracted from these treatments. Hybridizations were carried out with the senescence related cDNAs SR5, SR8, SR12, DCACO1, DCACS1, and DCCP. The respective transcripts showed distinct patterns of accumulation in response to ethylene. SR5 transcripts, encoding for a putative β-glucosidase, accumulated significantly faster and at lower ethylene concentrations than all the other transcripts. DCACS1, an ACC synthase, on the other hand showed a delay in the accumulation of its mRNA when compared to the other genes. As the petals develop each mRNA also showed a unique pattern of increased responsiveness to ethylene. This increase in responsiveness is expressed as a decrease in the ethylene-time constant. The ethylene-time concept, similar to degree-days, states that it takes a certain time for a given ethylene concentration to induce a response, 50% maximum transcript level in this study. This allows for a quantitative assessment of changes in ethylene responsiveness during petal development.
The Effect of a pH Gene on the Color of Petunia Flowers
Authors: Griesbach R.J.
Published: February 2019

An in vivo system was developed to determine the effects of pH on naturally occurring, pigment complexes within cells. The in vivo system was based upon a controlling element inserted into the Ph6 gene. The controlling element mutation was crossed into a genetically marked Petunia line expressing known flavonoid pigments. Flowers expressing the controlling element were variegated with the mutant background lighter in color than the revertant sectors. In the progeny, several individuals were found that had sectors that were a different flower color than the background. In these flowers, the background had a higher pH than the sectors. An increase in pH less than 0.5 unit changed the color from red to blue.
Navel Orange Pitting Stimulated by Waxing and High Storage Temperature
Authors: Dou Huating , Petracek Peter D. , Davis Craig
Published: February 2019

Navel oranges are reportedly susceptible to postharvest peel disorders, including chilling injury and aging/stem end rind breakdown. These and other physiological disorders are sometimes given the common term “navel rind breakdown.” California citrus industry reports on recent incidences of navel rind breakdown suggested that some instances of this disorder were similar to “postharvest pitting,” a disorder that we have observed in a number of Florida citrus varieties. Thus, we decided to define the morphology and etiology of pitting of `Washington' navel orange (Citrus sinensis L.) peel. The disorder was characterized by the collapse of clusters of oil glands and was stimulated by wax application and high temperature (≥13 °C) storage. Internal ethanol levels of waxed fruit stored at high temperature (13 or 21 °C) were significantly higher among fruit that developed pitting than those that did not. The pitting observed in these studies is comparable to previously observed navel orange disorders that have occurred without known cause. Navel orange pitting is morphologically and etiologically distinct from chilling injury and aging/stem end rind breakdown, but is similar to postharvest pitting of Florida citrus fruit.
Postharvest Quality of `Valencia' and Navel Oranges after High Temperature Forced-air Treatments
Authors: Patil B.S. , Sievert J.R. , Williamson M.R. , Winkelman P.M. , Arpaia M.L.
Published: February 2019

`Valencia' and navel orange (C. sinensis L. Osbeck) fruit quality was evaluated following exposure to either a cold treatment (21 days below 2.2 °C) or a high-temperature forced-air (HTFA) treatment (ramped: fruit center end point, 47.2 °C; and constant: 46 °C for 310 min). These treatments are approved as disinfestation measures against selected fruit flies (APHIS, 1996). Fruits were stored at either 5 or 1 °C (cold treatment) for 14 days followed by 10 days at 11 °C and 7 days at 20 °C. Fruits were obtained six times during the commercial `Valencia' and navel orange season (three grower lots/time). Fruits exposed to HTFA (ramped and constant) treatments had significantly lower appearance ratings, total soluble solids, titratable acidity as compared to control or cold treated fruits. Cold treated fruits had significantly higher L* values. Fruits were also presented to an untrained sensory evaluation panel. Both ramped and constant temperature treated fruits were rated significantly inferior in taste. Although statistically significant, these differences were slight. This research demonstrates the potential deleterious quality attributes of `Valencia' and navel oranges due to HTFA; however, we believe that cold treatment may be the efficacious quarantine treatment method for distant export market. The potential for HTFA treatments for CA citrus, in light of these results is discussed.
Irrigation Management Practices in Ohio
Authors: Sheaffer Cassandra C. , Rose Mary Ann
Published: February 2019

Expanding urbanization in Ohio has made the availability of quality water an emerging issue of great importance to the state's nursery industry. This development necessitates an examination of nurseries' use and management of water. This study surveyed 600 Ohio nursery growers with a mail questionnaire to determine the frequency of irrigation and water-saving techniques across the state. The 21-question questionnaire covered topics including water sources, irrigation practices, water testing and information needs. The mailing list used was the Ohio Dept. of Agriculture's licensed nursery operators list. Nonrespondents received a postcard reminder and a second copy of the survey within 3 months of the initial mailing, yielding a 45% response rate. Data was analyzed using SPSS software. Responses indicate approximately 57% of Ohio nurseries used irrigation in the 1997 growing season. For field production, 64%of nurseries used overhead irrigation for at least half of their irrigated production; for container production, 91%. Nearly 41% of respondents using irrigation reported capturing runoff for reuse this past year. The most common irrigation sources for Ohio nurseries were wells (79%) and ponds (62%). Additional goals for the project include raising awareness of water management and water quality issues, identify common water quality problems, and to obtain direction for future research and extension efforts.
Effects of Plant Growth Retardants and Application Timing after Shearing on Growth and Flowering of Coreopsis verticillata `Moonbeam'
Authors: Kessler J. Raymond , Keever Gary J.
Published: February 2019

Coreopsis verticillata `Moonbeam' is a herbaceous perennial that may grow too tall in small containers under greenhouse conditions for market acceptance, and therefore may benefit from plant growth retardants. Rooted terminal cuttings produced under short days were given a terminal pinch and transplanted to 10 cm pots. Cuttings were sheared to 6 cm above the pot rim 4 weeks later. Growth retardant treatments consisting of ancymidol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; paclobutrazol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; daminozide spray at 0, 2550, 5100, or 7650 mg·L–1; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 mg·L–1; or flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 mg·L–1 were applied 10 days after shearing. Night-breaking lighting using incandescent bulbs was started the same day. The highest rate of ancymidol, paclobutrazol drench, daminozide, and flurprimidol decreased plant height compared to controls by 36, 30, 21, and 36%, respectively. Paclobutrazol sprays were not effective. A market quality rating of four or higher (good, salable) was given to plants treated with daminozide at 5100 or 7650 mg·L–1 or flurprimidol at 150 or 200 mg·L–1. A second experiment was conduced to determine application timing. A daminozide spray at 0, 2550, 5100, or 7650 mg·L–1 was applied 0, 3, 6, 9, 12, or 15 days after shearing. Plant height, growth index and lateral shoot length were least and market quality rating highest when 5100 or 7650 mg·L–1 of daminozide was applied between 6 and 9 days after shearing.
Impact of Narrow Row Production on Yield Recovery, Nitrogen Use Efficiency, and Weed Competition in Sweet Corn
Authors: Fritz Vincent A. , Rosen Carl J. , Becker Roger L.
Published: February 2019

The processing industry is beginning to adopt narrow row configurations for sweet corn production thinking that plants spaced more equidistant will compete less with each other and weeds, improving yield potential and production efficiency. However, empirical knowledge relating to whether these proposed benefits change with hybrid, N fertility, and planting date is lacking. Narrow row (56 cm apart) sweet corn production was evaluated for improved production efficiency over the “traditional” row configuration (76 cm apart) at identical plant populations (60,000/ha). Yield from seed planted in narrow rows on 1 May was significantly higher than traditional row configuration. Increasing N fertilizer rate (0, 68, 136 kg N/ha) also yielded a positive linear response in yield across the three hybrids. As planting date progressed later into the season (27 May and 19 June), narrow row configuration benefits observed earlier began to diminish. Although increased N fertilizer rates continued to show a positive yield response across all planting dates, the degree of the slope decreased as planting date was progressively delayed suggesting a greater rate of N mineralization from the soil. Plant leaf samples were collected from each plot at silking for N analysis and determination of N use efficiency. Degree of canopy closure was dependent on plant architecture of the hybrid and N fertilizer rate; and may be related to postemergence weed competition and yield potential. The decision to convert to narrow row production would require a significant capital investment in new equipment. An economic assessment of the equipment required in addition to more detailed information on yield response to the narrow row configuration will help the processor make an informed choice when considering conversion.
Effect of Poultry Compost on Productivity and Quality of Beets
Authors: Rangarajan Anusuya , Stivers Lydia , Reiners Steve
Published: February 2019

One characteristic of compost that might provide greater incentive for use by vegetable growers is suppression of soil-borne diseases in crops grown on compost-amended soils. The mode of action of low rates of compost on vegetable growth may include stimulation of microbial activity for suppression of soil-borne diseases, enhanced plant resistance, and improved nutrient availability. Preliminary research on beets demonstrated that higher stands and decreased loss to root rot diseases in poultry compost-amended plots contributed to marketable yields which were twice that of the control plots. This presentation will summarize research results from studies to determine if compost reduced disease severity by changing in soil microbial activity or if these products primarily improved plant growth as a result of increased nutrient availability. Three field experiments explored impact of two commercially available poultry compost products (2 to 5 T/A) and two rates of chemical fertilizer, on growth and disease incidence on beets. Soil microbial activity was estimated using an enzyme assay, and soil nitrate-N and ammonium-N concentrations were also measured, three times over the season. Results indicated that these composts act primarily through a nutrient affect to enhance beet yield. Neither compost affected microbial activity in the top 8 inches of soil. Both products had significant, opposite effects on available soil nitrogen. One product significantly increased the amount of available soil nitrogen over the season and beet yields. The different methods of production of the two poultry composts tested in this research had significant implications for potential use in either greenhouse or field systems. The effects of these composts on crop fertility and composition will be discussed.
Inheritance of Pod Calcium Concentration in Snap Beans (Phaseolus vulgaris L.)
Authors: Quintana J.M. , Harrison H.C. , Nienhuis J. , Palta J.P. , Kmiecik K. , Miglioranza E.
Published: February 2019

Significant variation for pod Ca concentration among snap bean genotypes was previously observed. To evaluate and better understand the genetics that control calcium concentration of pods in snap bean, two populations of snap beans were evaluated during the summers of 1995 and 1996 at Hancock, Wis. These populations were Ca2 (`Top Crop' × `Evergreen') and Ca3 (`Slimgreen' × `Evergreen'), therefore forming a half-sib structure. The experimental design used in this experiment was an 8 × 8 double lattice repeated each year. No calcium was added to the plants, which were grown in a sandy loam soil with 1% organic matter and 600 ppm Ca. To ensure proper comparison for pod calcium concentration among cultivars, only commercial sieve size number 4 pods (a premium grade, 8.3 to 9.5 mm in diameter) were sampled and used for calcium extractions. After calcium was extracted, readings for calcium concentration of extracts were made using an atomic absorption spectrophotometer. Statistical analyses resulted in distinct differences among genotypes and between years for pod calcium concentration (P = 0.01) in both populations. No significant year × genotype interactions were observed. To assess the power of selection for pod calcium concentration in snap beans, variance components and heritabilities are estimated and discussed.