bluuebunny/crossref_metadata_2025 huggingface dataset:
Injury to Landscape and Vegetable Plants by Volatile Turf Herbicides
Authors: Busey Philip , Broschat Timothy K. , Johnston Diane L.
Published: December 2018

Phenoxy and related herbicides used in turfgrass have the potential for volatilization and movement from treated areas. Three studies assessed potential injury to subtropical landscape plants caused by volatile turf herbicides in polyethylene enclosures. Phenoxy herbicide mixtures were emphasized. There were significant differences among the seven landscape species tested. The most sensitive species were african marigold (Tagetes erecta), joseph's coat (Alternanthera ficoidea), and tomato (Lycopersicon esculentum). Severe injury was caused by exposure to herbicides containing 2,4-D isooctyl ester and MCPA isooctyl ester. Exposure to individual active ingredients 2,4-D dimethylamine, dicamba acid, atrazine, and metsulfuron resulted in no injury to the species tested.
Variety, Shading, and Growth Stage Effects on Pigment Concentrations in Lettuce Grown under Contrasting Temperature Regimens
Authors: Kleinhenz Matthew D. , Gazula Aparna , Scheerens Joseph C. , French Darla G.
Published: December 2018

Shading effects on chlorophyll a (ChlA), chlorophyll b (ChlB) and anthocyanin (Antho) concentrations were examined at three developmental stages in four varieties of lettuce (Lactuca sativa) grown under contrasting temperature regimens in the greenhouse. Seedlings were transplanted to pots and grown at 30 °C (86.0 °F) day/night (D/N) (Study 1) or 30/18 °C (86.0/64.4 °F) D/N (Study 2). One-half of all plants in each study were positioned under bottomless shade boxes which reduced incoming light intensity by 50%. Pigment concentrations were measured in leaf tissue 9, 16, and 23 days after transplanting. Each study was repeated twice. Regardless of temperature regimen, variety influenced all pigment concentrations, while shading affected, primarily, Antho concentrations. ChlA and ChlB concentrations were influenced by growth stage. In Study 1, chlorophyll concentrations were significantly greater in `Green Vision' than `New Red Fire' or `Rolina', but not `Galactic'. Also, Antho concentrations were significantly greater in `Galactic' than the other varieties. In Study 2, chlorophyll concentrations were greatest in `Green Vision', with similar concentrations among the remaining varieties. Antho concentrations were greatest in `Galactic', intermediate in `New Red Fire' and `Rolina', and lowest in `Green Vision'. Shading significantly reduced Antho concentrations in `Galactic' and `Rolina' under both temperature regimens and `New Red Fire' at 30/18 °C D/N, but increased Antho concentrations in `Green Vision'. Chlorophyll concentrations tended to decrease with plant age. Pigment concentration data clarified what was apparent to the unaided eye—namely, that the amount and intensity of green and red color varied among plants subjected to different shading and temperature treatments. Therefore, these data may aid in developing strategies to achieve targeted levels of pigmentation (especially red) in lettuce, an important criterion of crop quality and potential market value.
Sweet Corn Variety Trials in Ohio: Recent Top Performers and Suggestions for Future Evaluations
Authors: Kleinhenz Matthew D.
Published: December 2018

A total of 21 and 28 standard and experimental varieties of yellow and white se- and sh2-type sweet corn (Zea mays) were planted in 1999 and 2000 in Fremont and Wooster, Ohio, which are separated by 193.1 km (120 miles) and contain different soil types. Data are reported here for a subset of these varieties (eight yellow, two white) showing a consistently high level of use in Ohio and planted in both years. Endosperm types were planted in distinct, parallel experiments separated by a minimum of 79.9 m (262 ft) at each site. A randomized complete block design with four replications per variety (V) per location (L) was used, with measures of 13 production- and market-based variables taken from emergence to 48 hours after harvest. Soluble solids 48 hours after harvest were greater at Wooster than Fremont in the sh2 study. Variety had a significant, independent effect on mean plant and ear height in the se and sh2 study, respectively, although further analysis of year × variety (Y × V) and location × variety (L × V) interactions suggested that V affected additional traits. On average, `Tuxedo' (se) and `HMX6383S' (sh2) had superior com-binations of grower- and consumer-oriented traits. However, varieties with the highest levels of percent emergence and marketable yield tended to have lower levels of soluble solids, regardless of endosperm type. Y × V interactions were primarily due to changes in the magnitude of values for individual varieties in each year, not from changes in their relative ranking. The Y × L × V interaction was significant (P ≤ 0.05) for marketable yield, plant and ear height, and the ratio of ear length to diameter in the se study, but zero variables in the sh2 study. Coefficients of determination (R2) for selected plant and ear traits were unaffected by location. Overall, R2 values ranged from 0.04 (number of rows of kernels × ear diameter, sh2 study) to 0.83 (shank length × total ear length, sh2 study). These data reinforce that genetics strongly affect key traits in sweet corn and identify two potential top performers. The data also suggest that independent L or L × V effects may be minor relative to V effects, even when locations are separated by moderate distances and contain different soil types. Therefore, including more varieties but fewer sites may be warranted in future variety trials. The data also suggest that 1) ratings of variety performance should be based on objective measures of grower- and market-oriented traits and 2) shank length × total ear length and ear height × plant height relationships may be used to improve the efficiency of future evaluations.
Pretesting Public Garden Exhibits Enhances Their Educational Value for People with Diverse Abilities
Authors: Larson Jean M. , Hoover Emily
Published: December 2018

Formative evaluation (pretesting) can lead to better working exhibits in public gardens. While many botanical gardens and arboreta will attest to the importance of using formative evaluation, it has not been used to develop exhibits for consumers with diverse disabilities. At the Clotilde Irvine Sensory Garden of the University of Minnesota Landscape Arboretum (Chanhassen, Minn.) we are interested in developing exhibits that meet the needs of audiences with disabilities. To that end in 2000, four comprehensive interpretive exhibits were pretested before the final exhibits were installed within the Clotilde Irvine Sensory Garden to determine the exhibits ability to teach concepts to all regardless of disability. The evaluation indicated these exhibits were physically accessible, but needed attention in specific areas to enhance their inclusiveness.
Factors Associated with Decay in Table Beets Identified by a Statistical Analysis of Grower and Processor Records
Authors: Shah Denis A. , Stivers-Young Lydia
Published: December 2018

Data collected on 181 fields from 1998 to 2000 were analyzed for associations among cultural practices in table beet (Beta vulgaris) and levels of decay in the harvested beet roots. Increased risk of decay was associated with short rotations between beet crops, certain crop rotations in the four years before beets, the frequency of row cultivation, and narrow row spacing. Shielding during cultivation was associated with increased risk of decay, but the effect may be an indirect one. Decay levels were not associated with beet variety, the use of manure or preplant fertilizer. Decay did increase with higher rates of nitrogen side dressing. Mean decay differed significantly among growers, and could be explained in part by the set of cultural practices used by a grower. The results suggest that the risk of decay is determined by interacting biological and cultural factors. Manipulation of cultural practices and cropping sequence may be useful in managing levels of beet decay.
Growth and Development Responses of Ornamental Gingers to Photoperiod
Authors: Sarmiento Mauricio J. , Kuehny Jeff S.
Published: December 2018

Rhizomes of Curcuma alismatifolia `Chiang Mai Pink' and tissue cultured plants of C. cordata, C. petiolata `Emperor', C. thorelii, Kaempferia sp. `Grande', Siphonichilus decora and S. kirkii were grown in a greenhouse under 8-, 12-, 16-, and 20-hour photoperiods. All plants grown under the 8-hour photoperiod became dormant over a 15 week time period. After 90 days, most ginger species grown under the 16- and 20-hour photoperiods were taller than those grown under 8 and 12 hours. A larger number of unfolded leaves was indicated for all ginger species grown under 16- and 20-hour photoperiods compared to those grown under 8- and 12-hour photoperiods except for C. thorelli. The percentage of unfolded leaves as determined by quartile indicated similar results. The number of underground rhizomes of C. alismatifolia, C. cordata, and C. petiolata increased when plants were grown at 16 and 20-hour photoperiods. The number of tuberous-roots (t-roots) increased as photoperiod decreased below 16 hours for C. alismatifolia, C. cordata, C. petiolata, Kaempferia sp. and S. kirkii. Siphonichilus decora produced no t-roots while C. thorelii produced the most t-roots at 16 hours. Vegetative growth of gingers grown in this study, except for C. thorelii, was maintained and increased at photoperiods of 16 and 20 hours.

Photoperiods of 8 and 12 hours induced dormancy and t-root production of most of these gingers.
Evaluating Airborne Normalized Difference Vegetation Index Imagery for Citrus Orchard Surveys
Authors: Fletcher Reginald S. , Escobar David E. , Skaria Mani
Published: December 2018

The normalized difference vegetation index (NDVI) provides relative estimates of vegetation vigor, density, and health. Little information is available on the application of NDVI imagery for citriculture. The objective of this study was to evaluate airborne NDVI imagery for assessing tree conditions in citrus (Citrus spp.) orchards. Images of two south Texas citrus groves with stressed and nonstressed trees were qualitatively evaluated. Stressed trees were easily detected from nonstressed trees in the images. The images were also helpful for developing survey plans of the citrus groves. Our results indicated that airborne NDVI images could be used as a tool to assess tree conditions in citrus orchards. Findings should be of interest to citrus growers, extension agents, agricultural consultants, and private surveying companies.
Mechanical Shearing Device for Potted Rosemary Christmas Tree Topiaries
Authors: Warnock Daniel F.
Published: December 2018

Greenhouse production of rosemary (Rosemarinus officinalis) as small potted Christmas-tree topiaries for holiday sales have become necessary for many companies marketing to large retail outlets. Topiaries must be sheared multiple times to obtain an acceptable Christmas-tree shape. Most production greenhouses use hand pruning shears or hand-held cordless grass shears to shape topiaries free hand or with the aid of a template. Crop size and uniformity can vary with these shearing methods. To create a more uniform rosemary Christmastree topiary for cultivar evaluations, a mechanical shearing device constructed from over-the-counter parts was developed at the University of Illinois. A detailed description of the design and construction of this mechanical shearing device is presented in this report.
The Pennsylvania State University Medieval Garden: Using a Specialized Garden as an Alternative Teaching and Learning Environment
Authors: McGann Martin R. , Berghage Robert D.
Published: December 2018

The Pennsylvania State University Medieval Garden (PSMG) showcases varieties of medieval plants used as ornamentals, food crops, medicinal ingredients, and for household purposes in a stylized setting representing a medieval garden. Since its installation, various colleges within the university as well as community groups have used the garden as an alternative classroom for learning activities, educational demonstrations, and events related to the medieval period. This article focuses on the initial development of the garden design and how the installation and continued use as a classroom has contributed to meeting educational goals for students in the landscape contracting program at the Pennsylvania State University and the Pennsylvania Governor's School for Agricultural Sciences.
Processed Poultry Feather Fiber as an Alternative to Peat in Greenhouse Crops Substrates
Authors: Evans Michael R.
Published: December 2018

Plant growth was evaluated in substrates containing varying proportions of processed poultry feather fiber (feather fiber). `Cooler Blush' vinca (Catharanthus roseus) and `Orbit Cardinal' geranium (Pelargonium × hortorum) dry shoot and dry root weights were not significantly different among plants grown in sphagnum-peat-based and perlite-based substrates containing 0% to 30% feather fiber. `Pineapple Queen' coleus (Coleus blumei) dry shoot weights were not significantly different among plants grown in substrates containing 0% to 50% feather fiber. Coleus dry root weights were not significantly different among the substrates containing 0% to 40% feather fiber. `Better Boy' tomato (Lycopersicon esculentum) dry shoot weights were not significantly different among the substrates containing 0% to 30% feather fiber. Tomato dry root weights were not significantly different among the substrates containing 0% to 30% feather fiber, but tomato grown in substrates containing 40% to 60% feather fiber had significantly lower dry root weights than tomato grown in substrates containing 0% to 30% feather fiber. `Salad Bush' cucumber (Cucumis sativus) dry shoot and dry root weights were not significantly different between plants grown in 0% to 50% feather fiber, but those gown in substrates containing 60% feather fiber had significantly lower dry shoot weights than those grown in substrates containing 0% feather fiber. Dry shoot and root weights of coleus and tomato grown in SB-300 substrate amended with 20% or 30% feather fiber were not significantly different from coleus and tomato grown in SB-300 without feather fiber. Dry shoot and dry root weights of coleus and tomato were significantly lower for plants grown in SB-300 amended with 40% feather fiber than for plants grown in SB-300 without feather fiber. For all species tested, plants grown in substrates containing up to 30% feather fiber were not significantly different from those grown in substrates containing 0% feather fiber and were of marketable qualities.
Recementation of Crushed Ortstein by Leaf Extracts, Selected Organic Acids, and a Soil Amendment
Authors: Bronick C.J. , Mokma D.L. , Hanson E.J.
Published: December 2018

Ortstein (a soil layer cemented by organic carbon, aluminum, and iron; commonly referred to as hardpan) inhibits blueberry (Vaccinum corymbosum) growth. Growers have used deep tillage to break up ortstein, however, the benefits appear to have only been temporary. This study was conducted to determine if 1) crushed ortstein will recement, 2) depodzolizing species will reduce recementation, and 3) a commercially available soil amendment, Super Symbex 4X, will reduce recementation of crushed ortstein. Ortstein from Saugatuck sand (sandy, mixed, mesic Typic Durorthod) was crushed and passed through a 2-mm (0.079-inch) sieve and used in column experiments to assess recementation. Pieces of uncrushed ortstein were added to some columns to evaluate changes in cementation. Aqueous blueberry leaf extracts were added daily to columns for 1.5, 3, 6, and 12 weeks. Duplicate columns were treated with Super Symbex 4X and distilled water. Aqueous leaf extracts from bent grass (Agrostis perennans) and fescue (Festuca rubra) were added for 12 weeks. Solutions of protocatechuic acid (PCA), ρ-hydroxybenzoic acid (ρHBA), catechol and vanillic acid (VA) were added to crushed ortstein and allowed to stand for 5 weeks. Super Symbex 4X was added to the crushed ortstein and mixed with the organic acids at the recommended rate. Extensive recementation (96% aggregation) of crushed ortstein occurred after only 1.5 weeks of treatment with green blueberry leaf extract in the column experiments. Bent grass and fescue leaf extracts caused less and weaker recementation than blueberry. Addition of Super Symbex 4X to ortstein pieces did not produce an increase in size as did blueberry, bent grass and fescue leaf extracts. PCA, ρHBA and VA had high levels of recementation. The water control and catechol did not show high levels of recementation. Addition of Super Symbex 4X to the organic acid and crushed ortstein decreased recementation with the strongly recementing organic acids, PCA, ρHBA and VA. Super Symbex 4X appears to have potential to retard recementing of crushed or broken ortstein. Bent grass and fescue cover crops may not retard recementation of crushed ortstein.
Organic Fertilization of Fresh Market Sweet Basil in a Greenhouse
Authors: Succop C. Elizabeth , Newman Steven E.
Published: December 2018

Fresh-market sweet basil (Ocimum basilicum) is in high demand from specialty produce markets and commercial restauranteurs. Many consumers are also demanding produce that has been organically grown. Three hydroponic media systems were evaluated twice over two years, rockwool slabs, perlite frames, and commercial sphagnum peat/perlite/compost medium, where the bag was laid flat on the bench. Plants grown in these systems were fertilized with nutrient solutions derived from either organic or conventional, saltbased fertilizer sources. Few differences in yield were detected between basil plants grown in the commercial medium with either fertilizer source. Total yield from plants grown in perlite with the organic fertilizer was 22% greater in the first study and 100% greater in the second study than those for plants grown with the conventional fertilizer. Plants grown in rockwool with the conventional fertilizer were 17% more productive in the first study and 46% more productive in the second study than those grown with the organic fertilizer. Taste test panelists (69%) could discern differences between samples from organically and conventionally grown basil plants, yet no preferences were shown.
Economic Comparison of Initial Vine Density, Nitrogen Rate, and Weed Management Strategy in Commercial Cranberry
Authors: Sandler Hilary A. , DeMoranville Carolyn J. , Autio Wesley R.
Published: December 2018

A 2-year field trial examined the interaction of nitrogen rate, vine density, and weed management options for establishing new cranberry (Vaccinium macrocarpon) plantings. Utilizing the vigorous hybrid, `Stevens', the cost-efficiency of the treatment combinations was evaluated by combining cranberry and weed biomass data with various economic estimates. The most cost-effective production scheme for establishing new cranberry beds is to plant vines at a low density, use moderate rates of nitrogen, and apply an annual application of a preemergence herbicide. This combination produced substantial vine coverage at very low cost, reduced weed biomass by 85% compared to untreated plots, and gave the best weed control per dollar spent. Growers may opt for other reasonably successful combinations that involve higher labor costs if they can produce their own cuttings (reducing initial costs) or if they are farming with the intent to reduce overall synthetic inputs.
Optimum Timing of an Application of Corn Oil and Bacillus thuringiensis to Control Lepidopteran Pests in Sweet Corn
Authors: Cook Rosalind , Carter Anne , Westgate Pamela , Hazzard Ruth
Published: December 2018

Corn oil and Bacillus thuringiensis ssp. kurstaki (Bt) applied directly into the silk channel of a corn ear has been shown to be an effective pesticide against corn earworm, Helicoverpa zea (CEW), and european corn borer, Ostrinia nubilalis (ECB). Field studies were conducted in 2000 and 2001 to determine the influence of application timing on ear quality at harvest. Two blocks of corn were planted during each year to observe treatment effects under varying populations of the two insect species. The treatment consisted of 0.5 mL (0.017 floz) of food grade corn oil containing a suspension of Bt at 0.08 g (0.003 oz) a.i. per ear applied directly into the silk channel at the husk opening. One treatment application was made on each silk day 3 through 11 from first silk; silk day 1 was the first day that 50% or more of ears had 2.5 cm (1 inch) of silk protruding from the husk. One treatment did not receive the oil + Bt suspension. All ears were harvested at milk stage, on silk day 25. The number of CEW larvae in treated ears increased with later application days in 2000, but not in 2001. Damage from larval feeding was mainly found near the tip of the ear, and damage ratings were lower compared to untreated ears for all treatment days for both plantings in 2000, and through application day 8 in the late planting of 2001. ECB larvae were reduced for all treatment days in both plantings in 2000 and the late planting of 2001. The percentage of ears rated as marketable (i.e., free of feeding damage) ranged from 71% to 100% in treated plots compared to 30% to 77% in the untreated plots. There was a linear decrease in marketability with later application days in two of the four plantings. The greatest decrease in marketability was after application day 7. Because the oil application affects kernel development at the tip, the length of ear with under-developed kernels, or cone tip, was measured. The number of ears with cone tip decreased linearly with the later application days in all plantings. There was 10% conetip or less after day 7 in 2000 and day 6 in 2001. The best combination of effective insect control resulting in the highest rates of marketable ears with the least degree of cone tip was achieved in this experiment by application of oil + Bt suspension on day 7. Year to year variation in the environment would suggest a range from day 6 to 8.
Enhanced Rooting of Kinnikinnick Cuttings using Mycorrhizal Fungi in Rooting Substrate
Authors: Scagel C.F.
Published: December 2018

Hardwood cuttings of kinnikinnick (Arctostaphylos uva-ursi `Massachusetts') were inoculated with three different types of inoculum of mycorrhizal fungi to determine whether addition of mycorrhizal inoculum into the rooting substrate during cutting propagation increases rooting or root growth, or alters the time for rooting. Cuttings, treated or untreated with rooting hormone prior to sticking into the rooting substrate, were inoculated with either inoculum of an arbuscular mycorrhizal fungus (AMF), hyphal inoculum of an arbutoid mycorrhizal fungus (E), or inoculum consisting of colonized root fragments of kinnikinnick (R). Cuttings were placed under mist in a greenhouse with no bottom heat and harvested 35, 56, and 84 days after sticking. Using AMF inoculum in the rooting substrate did not enhance rooting of cuttings, while adding the R or E inoculum to the rooting substrate increased root initiation compared to non-inoculated cuttings. Cuttings inoculated with either the R or E inoculum had greater root initiation than non-inoculated cuttings 56 and 84 days after sticking. When treated with rooting hormone, cuttings inoculated with the E or R inoculum had longer roots and a greater root biomass than non-inoculated cuttings. Mycorrhizal colonization of roots was similar or greater when cuttings were inoculated with the E inoculum than with the R inoculum and application of rooting hormone generally increased root colonization. The use of inoculum composed of root fragments from kinnikinnick during cutting propagation does not appear to be more beneficial than use of hyphal inoculum from a known arbutoid mycorrhizal fungus.
Effect of Forward Speed on Hill Dropping Uniformity of a Precision Vacuum Seeder
Authors: Karayel Davut , Özmerzi Aziz
Published: December 2018

The purpose of this research was to examine the effects of different forward speeds of hill dropping melon (Cucumis melo) and watermelon (Citrullus lanatus) seeds with reference to hill dropping uniformity. For this purpose, melon and watermelon seeds were hill dropped with three different seed plates at the forward speeds of 0.5, 1.0, 1.5, and 2.0 m·s–1 (1.64, 3.28, 4.92, and 6.56 ft/s). A precision vacuum seeder unit was used in laboratory tests involving a grease belt test stand. Mean hill distance was not affected by forward speed and seed plates, but mean seed number in hill was affected. In terms of the coefficients of variation of hill distance and seed number in hill, the most suitable forward speed was 0.5 m·s–1. The scattering distance ratios of forward speed of 0.5 and 1.0 m·s–1 were about 20% to 30%, indicating an acceptable level for hill dropping of melon and watermelon.
Short-term Pulsing Improves Postharvest Leaf Quality of Cut Oriental Lilies
Authors: Leonard Ria T. , Nell Terril A.
Published: December 2018

Several pulse solutions were tested for their effectiveness in preventing leaf senescence on four cut oriental lily cultivars (Lilium sp. `Acapulco', `Kissproof', `Noblesse' and `Star Gazer'). Stems were pulsed 24 hours after harvest for 1 hour, stored in boxes in the dark for 5 days at 3 °C (37.4 °F) then evaluated in postharvest conditions. A new commercial product called Chrysal BVB, a proprietary mixture manufactured by Pokon & Chrysal (Miami) containing cytokinine and gibberellic acids, was the most effective product tested. Chrysal BVB [1 mL·L–1 (0.1%)] prevented leaf chlorosis and abscission on `Acapulco' and `Noblesse' and significantly reduced it by 82% on `Star Gazer' and by 69% on `Kissproof'. Stems pulsed in Fascination, a commercial mixture containing 1.8% gibberellins (GA4+7) and 1.8% benzyladenine [5.4 mg·L–1 (ppm) each], virtually prevented leaf chlorosis on `Noblesse', reduced it by 50% or more on `Acapulco' and `Star Gazer', and significantly delayed it 8 days on `Kissproof'. A 10 μm (2 ppm) pulse in thidiazuron, a substituted phenylurea with cytokinin-like properties, delayed leaf chlorosis on `Star Gazer' but to a lesser extent compared to BVB and Fascination. Chrysal SVB, a propri-etary mixture manufactured by Pokon & Chrysal containing gibberellic acid, had no effect on reducing leaf chlorosis on `Star Gazer'. None of the pulse solutions had adverse effects on bud opening, flower quality or vase life. Maintaining stems in a bulb flower preservative significantly reduced leaf chlorosis and abscission in all cultivars when stems were not pretreated with a pulse solution or when a pulse solution was ineffective.
Why Master Gardeners Stop Volunteering: Lack of Time
Authors: Meyer Mary Hockenberry
Published: December 2018

Nearly 300 Master Gardeners (MGs) who stopped volunteering were surveyed as to why they did not continue in the program. The fivequestion survey was mailed to people who had not turned in volunteer hours for the previous two years. Forty-seven percent or 131 useable surveys were returned and tabulated. A majority of the respondents, 73 (56%), indicated “no time” as the primary reason for not volunteering. Illness or personal reasons accounted for 30 responses (23%), and 20 people (15%) indicated they were disappointed in the program. Eighty-one percent rated the program as excellent or good; 79% indicated they would recommend the program to others.
Using a Pot-sized Demonstration to Teach the Effects of Season Extension Materials on the Early Growth of Winter Squash
Authors: Carter Anne K.
Published: December 2018

In the northeastern United States, vegetable crop classes and growers' meetings are often held during winter months when field demonstrations are impossible. A pot-sized demonstration was set up in the greenhouse in May and Nov. 2002 as a student laboratory to show the effects of season extension materials on the early growth of winter squash. The treatments were black plastic mulch and rowcover, alone and in combination. The treatments were also placed on either a heated [18.3 °C (65 °F)] or unheated germination mat to simulate warmer and cooler spring soils. Butternut squash (Cucurbita moschata) was sown in 10.2 × 10.2 × 11.43-cm (4 × 4 × 4.5 inches) pots in soilless medium. The plants were grown and observed for 30 days, then harvested and weighed. The plants in the greenhouse grew as expected of plants grown under similar conditions in the field. Bottom heat, mulch, and rowcover had an increasingly greater effect on the growth of subsequent leaves as shown by comparisons of leaves 1, 2, and 3. Warmer soils tended to have the greatest effect on all measured parameters, but this was not as obvious in the May experiment as it was in the November experiment. Thus, this pot demonstration can be used in a student laboratory. The pots and plants are small enough to transport to and set up at winter growers' meetings as well.
Group-based On-site Active Learning (GOAL): Technique for Investigating Nitrogen Management in Container Nurseries
Authors: Sandrock David R. , William Ray D. , Azarenko Anita N.
Published: December 2018

Nitrogen (N) management in container nurseries is part of a complex system. Working within this system, nursery owners, managers and employees routinely make N management decisions that have consequences for the immediate nursery environment (e.g., plant growth, yield, disease susceptibility, water quality) as well as areas beyond nursery boundaries (e.g., surface and groundwater quality, public perception). Research approaches often address parts of the system associated with the immediate nursery environment and purpose. As a result, best management practices that contribute to greater N use efficiency have been developed. Research approaches that consider the whole system reveal novel relationships and patterns that identify areas for future research and may direct future management decisions. To investigate N management from a whole system perspective, a group of nursery managers from Oregon and scientists from Oregon State University met three times between 2001 and 2003. Growers drew their N management systems and identified components, relationships and feedback loops using an ActionGram technique. From this information, researchers developed Group-based On-site Active Learning (GOAL). GOAL combines Action-Grams and the Adaptive Cycle at container nursery sites. In this case, N flow and management in container production systems served as the topic of active learning. Managers and employees from four wholesale container nurseries evaluated the GOAL exercise. After completing GOAL, 94% of participants indicated that they learned a new idea or concept about N cycling in their container nursery. Of those, 100% gained new ideas and concepts from peers and colleagues present at the meeting. In addition, 60% gained new ideas and concepts from researchers and 60% developed their own ideas and concepts. GOAL is a learning tool that provides a simple, convenient, interactive format for investigating complex systems.
Germinating Seeds of Wildflowers, an Ecological Perspective
Authors: Baskin Carol C. , Baskin Jerry M.
Published: December 2018

Five kinds (classes) of seed dormancy are known: physiological (PD), morphological (MD), morphophysiological (MPD), physical (PY), and combinational (PY+PD). PD is the most common class in the major vegetation zones of the world followed by PY, MPD, MD, and (PY+PD). Each class is described, and a dichotomous key to identify them is presented. The environmental conditions required to break PD, MD, MPD, PY, and (PY + PD) and promote germination are discussed. To help determine which treatments to use for breaking dormancy in seeds with water-permeable seedcoats (PD, MD, MPD), a “move-along experiment” is recommended. Little or no convincing evidence for the role of microbes or mechanical abrasion by soil particles in breaking PY can be found in the literature. However, there is good evidence that the water plug or gap in the seed or fruit coat of seeds with PY responds to environmental cues that permit timing of imbibition and germination to be well controlled in nature. Seeds of many species remain viable after passing through the digestive tracts of animals, with varying effects on germination.
Growth of Bedding Plants in Substrates Amended with Compost and Fertilized with Three Different Release Rates of a Controlled-release Fertilizer Product
Authors: Moore Kimberly K.
Published: December 2018

Growth of `Aladdin Peach Morn' petunia (Petunia × hybrida) and `Accent White' impatiens (Impatiens wallerana) was compared in substrates containing 0%, 30%, 60%, or 100% compost made from biosolids and yard trimmings and fertilized with Nutricote Total 13-13-13 (13N-5.7P-10.8K) Types 70, 100, and 140 incorporated at rates of 0.5x, 1x, 2x, or 3x (x = standard application rate for a medium-feeding crop). Petunia shoot dry weight of plants fertilized with Type 70 incorporated at 0.5x increased as the percentage of compost in the substrate increased from 0% to 60% and then decreased, while shoot dry weight of plants fertilized with Type 70 incorporated at 1x, 2x, or 3x increased as the percentage of compost increased from 0% to 30% and then decreased. Impatiens shoot dry weight of plants fertilized with Type 70 incorporated at 0.5x and 1x also increased as the percentage of compost increased from 0% to 30% and then decreased, while shoot dry weight of plants fertilized at 2x and 3x decreased as the percentage of compost increased from 0% to 100%. Both petunia and impatiens shoot dry weight of plants fertilized with Type 100 and Type 140 incorporated at 0.5x, 1x, 2x, or 3x increased as the percentage of compost increased from 0% to 60% and then decreased.
Rooting of Rose Cuttings in Response to Foliar Applications of Auxin and Surfactant
Authors: Blythe Eugene K. , Sibley Jeff L. , Tilt Ken M. , Ruter John M.
Published: December 2018

In five experiments, singlenode cuttings of `Red Cascade' miniature rose (Rosa) were treated with a basal quick-dip (prior to insertion into the rooting substrate) or sprayed to the drip point with a single foliar application (after insertion) of Dip `N Grow [indole-3-butyric acid (IBA) + 1-naphthaleneacetic acid (NAA)], the potassium salt of indole-3-butyric acid (K-IBA), or the potassium salt of 1-naphthaleneacetic acid (K-NAA); a single foliar spray application of Dip `N Grow with and without Kinetic surfactant; or multiple foliar spray applications of Dip `N Grow. Spray treatments were compared with their respective basal quick-dip controls {4920.4 μm [1000 mg·L-1 (ppm)] IBA + 2685.2 μm (500 mg·L-1) NAA, 4144.2 μm (1000 mg·L-1) K-IBA, or 4458.3 μm (1000 mg·L-1) K-NAA}. Cuttings sprayed with 0 to 246.0 μm (50 mg·L-1) IBA + 134.3 μm (25 mg·L-1) NAA, 0 to 207.2 μm (50 mg·L-1) K-IBA, or 0 to 222.9 μm (50 mg·L-1) K-NAA resulted in rooting percentages, total root length, percent rooted cuttings with shoots, and shoot length similar to or less than control cuttings. Exceptions were cuttings sprayed with 0 to 2.23 μm

(0.5 mg·L-1) K-NAA, which exhibited shoot length greater than the control cuttings. Addition of 1.0 mL·L-1 (1000 ppm) Kinetic organosilicone surfactant to spray treatments resulted in greater total root length and shoot length. Repeated sprays (daily up to seven consecutive days) had no or negative effects on root and shoot development.
Influence of Silicon on Drought and Shade Tolerance of St. Augustinegrass
Authors: Trenholm Laurie E. , Datnoff Lawrence E. , Nagata Russell T.
Published: December 2018

The objectives of these studies were to evaluate the effects of silicon on drought and shade tolerance of st. augustinegrass (Stenotaphrum secundatum). Studies were conducted during 2001 in a glasshouse at the University of Florida Turfgrass Research Envirotron in Gainesville. For both drought and shade evaluations, calcium silicate slag (CaSiO3) was pre-incorporated into pots with commercial potting soil at the rate of 3.36 kg·ha-1 (0.069 lb/1000 ft2). `FX-10' and `FHSA-115' st. augustinegrass were planted into 15.2-cm-diameter × 30.5-cm-deep (6 × 12 inches) plastic pots for the drought study and subjected to minimal irrigation. Under severe drought stress, silicon-amended plants had better responses than non-amended plants. Little improvement was seen under moderate drought stress. `Floratam' and genotype 1997-6 were placed under full sunlight or 50% to 70% shade. There was no benefit from use of silicon under shaded conditions. These findings suggest that silicon might provide improved tolerance to st. augustinegrass under severe drought stress.
Fruit Yield and Quality of Greenhouse-grown Bell Pepper as Influenced by Density, Container, and Trellis System
Authors: Jovicich Elio , Cantliffe Daniel J. , Stoffella Peter J.
Published: December 2018

Production and quality of bell pepper (Capsicum annuum) fruit were evaluated in a passively ventilated greenhouse, in soilless media trellised to a “V” system (two-stempruned plants) or the “Spanish” system (nonpruned plants) in flat bags or nursery pot containers; and densities of 1.5, 1.9, 3.0, and 3.8 plants/m2 (0.14, 0.18, 0.28, and 0.35 plants/ft2), in a winter-to-summer-crop in Gainesville, Fla. The trellis systems did not affect total marketable fruit yields but production of extra-large fruit was higher (38%) in non-pruned than in pruned plants. Marketable fruit yields were similar in plants grown in bags and pots, and had positive linear responses to increased plant density. Not pruning reduced by half the percentage of fruit with blossom-end rot. Pruned plants produced 50% fewer flower bud supporting nodes than non-pruned plants but had a greater percentage of fruit set. Regardless of trellis systems, fruit set per plant decreased linearly as plant density increased. Overall, the “Spanish” trellis system at a density of 3.8 plants/m2 resulted in greater yields of extra-large fruit and required 75% less labor than the “V” system to prune and support the plant canopy.
Rind Thickness of Watermelon Cultivars for Use in Pickle Production
Authors: Gusmini Gabriele , Schultheis Jonathan R. , Wehner Todd C.
Published: December 2018

Salted and sweet watermelon rind pickles are commonly produced in North America, Europe, and Asia using traditional recipes. Homeowners and small industries use the leftover watermelon crop, especially from cultivars having thick and crisp rind, to produce pickles. Recently, we classified rind thickness for a set of obsolete and heirloom cultivars used by home gardeners and heirloom collectors in the United States. In this study, we used elite cultivars for growers interested in high yield, fruit quality, adaptability, and disease resistance. The objective of this study was to classify modern cultivars (nine inbreds and 103 F1 hybrids) of watermelons available to growers for use in production of watermelon rind pickles. Based on the data, cultivars were divided into three groups of rind thickness and categorized according to pedigree (inbred or F1 hybrid), fruit type (seeded or seedless), and flesh color (red, orange, or yellow). Most of the cultivars tested (109 of 112) had rind thicker than 10 mm and could be used for pickle production.
Minimizing Direct Deposition of Pesticides into Waterways Associated with Indian River Citrus Production
Authors: Wilson Chris , Stover Ed , Boman Brian
Published: December 2018

Off-target deposition of pesticidal spray material is both an economic loss to the grower and a potential environmental problem in southern Florida. This study evaluated the reduction in non-target deposition of copper resulting from different approaches to spraying row-ends in typical Indian River citrus (Citrus) production systems. Using copper as a model pesticide, applications were made in a commercial citrus grove in June and July 2001. Non-target deposition on the water surface within an adjacent drainage canal, as well as on surrounding ground surfaces, was measured using Teflon spray targets. Specific row-end spraying scenarios included: 1) leaving both banks of nozzles on while turning; 2) turning the outside-facing nozzles off (leaving tree-facing nozzles on); 3) turning both banks of nozzles off at the tree trunk; and 4) turning all nozzles off at the end of the foliage of the last tree within the row. Deposition directly onto surface water contained within drainage canals was reduced significantly when nozzles were turned off at the last tree within a row, or when the outside-facing nozzles-only were turned off through the turn. Likewise, deposition was reduced on ground surfaces adjacent to the sprayer under the same scenarios. No differences were observed on ground surfaces on the opposite side of the canal. Significant reductions in direct application of agrichemicals to surface waters within Indian River citrus production groves can be achieved by turning nozzles off when turning from one tree row into the next.
The Horhizotron™: A New Instrument for Measuring Root Growth
Authors: Wright Amy N. , Wright Robert D.
Published: December 2018

Root growth following transplanting allows a plant to exploit water and nutrient resources in the soil backfill (landscape) or container substrate and thus is a critical factor for transplant survival. The Horhizotron, a horizontal root growth measurement instrument, has been developed and evaluated for use in measuring root growth under a variety of root environments. The design of the Horhizotron includes four wedge-shaped glass quadrants that extend away from a plant's root ball allowing measurement of roots as they grow out from the original root ball. The substrate in each quadrant can be modified in order to evaluate the effect of substrate or root environment on root growth. Materials used for construction were lightweight, durable, easy to assemble, and readily available from full service building supply stores. Units were suitable for use on a greenhouse bench or outdoors in contact with the ground. Horhizotrons provided a simple, nondestructive method to measure root growth over time under a wide range of rhizosphere conditions.
Evaluation of 14 Butterfly Bush Taxa Grown in Western and Southern Florida: II. Seed Production and Germination
Authors: Wilson Sandra B. , Mecca Laurie K. , Gersony Judith A. , Thetford Mack , Raymer Josiah S.
Published: December 2018

Because of its weedy nature, extensive use in the landscape, numerous cultivars, and history as an invasive plant in other countries, butterfly bush (Buddleja) was an appropriate candidate to evaluate for seed production and germination in Florida. Seed production was quantified for 14 butterfly bush taxa planted in western Florida (Milton) and central southern Florida (Fort Pierce). Each of the 14 taxa evaluated produced seed. In Fort Pierce, japanese butterfly bush (B. japonica) had the greatest capsule weight and `Gloster' butterfly bush (B. lindleyana) had the second greatest capsule weight as compared to other taxa. In Milton, `Gloster' had the greatest capsule weight and japanese butterfly bush and `Nanho Alba' butterfly bush (B. davidii var.nanhoensis) had the second greatest capsule weights as compared to other taxa. The shape and number of seed capsules per infructescence varied with cultivar. Seeds were cleaned and germinated in germination boxes with and without light at 20/10, 25/15, 30/20 and 35/25 °C (68.0/50.0, 77.0/59.0, 86.0/68.0 and 95.0/77.0 °F). Regardless of temperature or cultivar, light was required for germination. At each temperature, `Nanho Blue' butterfly bush (B. davidii var. nanhoensis) and `Moonlight' butterfly bush (B. × weyeriana) had highest germination rates (63-74%) as compared to other taxa.
Is an Instructional Video Better than a Face-to-face Demo to Teach T-budding in an Intro Plant Propagation Course?
Authors: Gómez Nadilia
Published: December 2018

Teaching grafting techniques like T-budding is challenging because learners must pay close attention to detail, observing closeups of plant structures and following specific sequences, and such attention to detail is difficult to achieve in large enrollment classes. The objective of this study was to compare the effectiveness of an instructional video vs. traditional face-to-face demonstrations to teach T-budding. A 10-minute instructional video demonstrating the steps necessary for T-budding was developed in 2001. For three consecutive years (2001, 2002, and 2003) the two methods were compared by having students see a video or receive a face-to-face demonstration, asking them to graft three buds to a root-stock and then complete a survey. Ninety students were taught T-budding with the aid of the video, and 80 students received traditional, face-to-face demos. In the survey, students were asked to evaluate the clarity of the T-budding instructions, rate the amount of help they needed from the instructor, assess the level of difficulty of T-budding, and answer two questions that tested their conceptual knowledge of T-budding. There was no difference between the two groups in the amount of time it took for students to complete the assignment and in terms of the perceived level of difficulty of the assignment. Students reported that the clarity of the face-to-face demonstrations was better than that of the video presentation, but students who saw the video obtained higher scores in the quiz than those who received a face-to-face demonstration.
Fertilizer Use for Horticultural Crops in the U.S. during the 20th Century
Authors: Mikkelsen Robert L. , Bruulsema Thomas W.
Published: December 2018

Tremendous changes have occurred during the past century in the sources and methods for supplying nutrients for horticultural crops. Reliance on animal manure, cover crops, and animal tankage was insufficient to meet the crop nutrient demand for a rapidly expanding population. The Haber-Bosch process for ammonia synthesis (1910s) revolutionized the availability and affordability of nitrogen (N) fertilizer. Discovery of large-scale deposits of rock phosphate in South Carolina (1860s) and Florida (1880s) alleviated widespread nutrient deficiencies. Acidification of rock phosphate and bone material significantly improved phosphorus (P) availability for plants. Discovery of potassium (K)-bearing minerals in New Mexico (1920s) and later in Canada (1960s) now provide a long-term nutrient source. Modern fertilizer technology allows nutrients to be applied in the correct ratio and amount to meet crop needs. Advances in understanding plant nutrition, coupled with slow-release fertilizers, foliar fertilization, soluble nutrients, and the development of soil and tissue testing have all improved the yield and quality of horticultural crops. Future developments will likely focus on fertilization in an increasingly competitive global economy, while requiring sophisticated management to minimize environmental impacts.
New Mechanical Harvesters for the Florida Citrus Juice Industry
Authors: Brown Galen K.
Published: December 2018

Hand picking, by snapping each fruit from its stem, has been the traditional method of harvesting Florida oranges (Citrus sinensis) and grapefruit (C. paradisi) for processing. A harvest mechanization program was active from about 1960 to 1985, but mechanical methods were not adopted. In July 1994, a new harvesting research and development program was initiated by the Florida Department of Citrus. The growers are taxed about $0.01/field box of production to fund the program. An industry Advisory Council oversees the program, and recommends projects and funding. The new program has provided training videos to improve hand harvest management/productivity, developed several methods for mechanical harvesting, and discovered/evaluated several fruit abscission agents. Mechanical harvesting use is increasing, and about 6880 of the 237,498 ha (17,000 of the 586,859 acres) of oranges were mechanically harvested during the 2002-03 season. Two mechanical systems can increase labor productivity by 5 to 15 times and reduce unit harvesting cost by 50% or more. Such savings are essential for effective competition in free-trade markets and for operation with resident labor. Many old-style plantings will need to be replaced over the next 10 years. The harvesting program accomplishments are discussed.