bluuebunny/crossref_metadata_2025 huggingface dataset:
(279) Morphological Investigation of Astilbe
Authors: Trader Brian W. , Scoggins Holly L. , Veilleux Richard E.
Published: February 2019

The genus Astilbe (Saxifragaceae) is comprised of approximately 20 species and is ranked consistently among the top ten landscape perennials. Through extensive hybridization, selection, and marketing, the lineage of many Astilbe has been lost. Subdioecious Astilbe biternata is the only species in the genus native to North America, while other members of the genus are endemic to Asia and monoecious. Due to the unusual geographic distribution of the species and the variation in floral development among them, investigation of morphological characters may help establish lineage within the genus. Herbarium material representing described species and varieties of Astilbe was acquired from several herbaria nationwide. Twenty-seven character states were selected to help distinguish members among the genus. Morphological character states chosen for inferring differences among species in Astilbe varied from degree of pubescence to leaf branching with an emphasis on floral characteristics such as sepal and petal variation. Character state matrix was assimilated for 20 taxa of Astilbe and analyzed using maximum parsimony. The monotypic genus Saxifragopsis was utilized as the outgroup taxa. Resulting phylogenetic trees show Astilbe simplicifolia as the species from which all members of the genus were derived. The American species, Astilbe biternata, separated away from other members within the genus. There is evidence from the phylogeny based on the morphological character states that some described species may actually represent variation within populations of species. Combination of this morphological data with molecular sequence information may be informative for further description of the Astilbe genus.
(56) Salt Spray Tolerance of Miscanthus sinensis `Gracillimus' and Pennisetum setaceum `Hamelin'
Authors: Alvarez Erin E. , Sandrock David R.
Published: February 2019

Salt tolerance of landscape plants is important to ornamental growers as well as residents and landscapers in coastal communities. Damage to ornamental plants from salt spray can be prevented by evaluating and selecting plants that exhibit tolerance to aerosol salts. Ornamental grasses are frequently recommended for low-maintenance landscape situations and may be candidates for coastal plantings once they are evaluated for their salt spray tolerance. The objective of this study was to determine the salt spray tolerance of Miscanthus sinensis `Gracillimus' and Pennisetum setaceum `Hamelin'. The experiment was conducted for 90 days from 7 July to 5 Oct. 2005 in a polyethylene greenhouse in Gainesville, Fla. Plants were subjected to four treatments (100% seawater, 50% seawater, 25% seawater, or 100% deionized water) applied by spraying each plant to runoff three times per week. Plant heights, flower number, and aesthetic ratings were recorded biweekly for the duration of the experiment. Root and shoot dry weights were determined at the initiation and completion of the study. Significant growth rate differences were found between treatments. Growth rates of plants treated with 100% seawater were significantly lower than the control and other seawater concentrations. Root and shoot dry weights of the plants treated with 100% seawater were significantly lower than the other treatments. In addition, significant differences were found between the 100% seawater treatment, the 25% seawater treatment, and the control in the aesthetic ratings of plants at the end of the study.
(239) Evaluation of Self-compatibility in Clethra alnifolia
Authors: Reed Sandra M.
Published: February 2019

Clethra alnifolia, which is commonly known as summersweet, is an attractive deciduous shrub that produces fragrant flower in mid-summer. Breeding efforts are hampered by a lack of information on the reproductive behavior of this native species. The objective of this study was to evaluate self-compatibility in C. alnifolia. Pollen germination and pollen tube growth in styles were examined following self- and cross-pollinations using fluorescence microscopy. Seed set and germination were compared following self- and cross-pollinations. While self-pollen tubes appeared to grow slightly slower than cross-pollen tubes, there was no indication of a self-incompatibility system acting at the stigmatic or stylar level in C. alnifolia. Self-pollinations of `Hummingbird' and `Ruby Spice' produced fewer seeds than did cross-pollinations of these cultivars. Germination of all seed obtained from this study was too poor to allow a comparison of germination rates of the self- and cross-pollinated seed. However, because a few self-progeny were obtained, emasculation is recommended when making controlled pollinations. The presence of a late-acting self-incompatibility system or early acting inbreeding depression was proposed as being responsible for the lower seed set following self-pollination.
(241) Susceptibility of Catalpa, Chilopsis, and Hybrids to Powdery Mildew and Catalpa Sphinx Larvae
Authors: Olsen Richard T. , Ranney Thomas G.
Published: February 2019

A diverse collection of germplasm representing 24 taxa from Catalpa sect. Catalpa Paclt and sect. Macrocatalpa Grisebach, Chilopsis D. Don, and ×Chitalpa Elias & Wisura were screened for susceptibility to powdery mildew (PM), Erysiphe elevata (Burr.) U. Braun & S. Takam, and Catalpa sphinx larvae (CSL), Ceratomia catalpae (Boisduval), feeding. The PM screening was conducted in 2004–05, with plants grown in a lathhouse (50% shade) in 2004, and a gravel pad (100% full sun) in 2005. The PM causal organism was identified as Erysiphe elevata both years. Disease incidence and severity were recorded at 2-week intervals for 6 weeks and used to calculate area under the disease progress curves (AUDPC) for each taxon for each year. North American Catalpa in sect. Catalpa, Chilopsis, and ×Chitalpa taxa were all moderate to highly susceptible to PM. Chinese Catalpa in sect. Catalpa and West Indian species in sect. Macrocatalpa were resistant to PM. Hybrids between North American and Chinese Catalpa in sect. Catalpa varied in susceptibility, indicating inheritance of partial resistance to PM. A no-choice feeding study conducted with CSL in 2005 found no differences in survival or growth of larvae reared on taxa from Chilopsis, ×Chitalpa, or either section of Catalpa. Future breeding of ×Chitalpa can utilize two different sources of PM resistance, but a source for resistance to CSL was not identified.
(58) Evaluation of Select Perennial Ornamental Cultivars for Potential Roadside Beautification Application
Authors: Pacumbaba Rodulfo O. , Sabota Catherine , Britton Rhonda
Published: February 2019

Sixty-six perennial ornamental cultivars were established and then grown under low maintenance, intensive weed competition, and severe mowing conditions. These cultivars were evaluated for their potential application for roadside/median beautification. Experimental plots were cleared with Roundup® prior to planting. During the first 3 weeks of establishment, plants were irrigated as needed. Plants were grown for one season, then pruned back to simulate bush-hog mowing. Plants were grown under low maintenance and no weed control conditions for two growing seasons. Plants were evaluated each season for simulated bush-hog damage recovery potential, survivability under severe weed competition, height, and spread. Two-way analysis of variance with repeated measurements showed that height and spread variation had a significant interaction between plant cultivar and time of evaluation. Several Zephyranthes sp. cultivars performed poorly under severe weed competition and mowing damage resulting in a high mortality rate. Cultivars that did perform well for the 2-year evaluation period include Lagerstroemia indica ×fauriei `Natchez,' Lagerstroemia indica ×fauriei `Muskogee,' Vitex agnus-castus `Shoal Creek,' and Myrica cerifera. Rosa × `Chuckles' and Rosa × `Knock Out' cultivars, with their popular showy appearance, performed moderately well and showed high potential for roadside/median beautification applications.
(192) Effect of Controlled Atmosphere in Postharvest Life of `Elliot' Blueberry
Authors: Luchsinger Luis , Villalobos Alvaro , Lizana Antonio
Published: February 2019

Postharvest response to high CO2 controlled atmosphere (CA) was studied in the blueberry (Vaccinium corymbosum L.) cultivar Elliot. Fruit was stored at 0 °C, 90% relative humidity and 15%, 18%, and 21% of CO2 and 5% of O2 and in air (0.03% CO2 and 21% O2). Evaluations were performed after 30 and 60 days of storage and an aditional period of 3 and 6 days at 10 °C (ripening period). Parameters meassured were: color (lightness, hue, and chroma), firmness, soluble solids (SS), titrable acidity (TA), SS/TA ratio, pH, weight loss, decay, physiological disorders, and appearance. The CA caused a positive effect, preserving the quality of the fruit in storage, by decreasing the respiratory rate and decay incidence. The 15% CO2 controlled atmosphere presented the best firmness and lowest decay. Acceptable conditions of quality were kept for 60 days of storage.
(321) Development of a GIS-based Model for Predicting Sweetpotato Weevil Infestation Risk in Louisiana: Progress, Problems, and Prospects
Authors: Villordon Arthur , Roussel Craig , Hardy Tad
Published: February 2019

The sweetpotato weevil [SPW, Cylas formicarius (Fabricius)] is an important economic pest in “pink-tagged” or SPW-infested areas of Louisiana. From time to time, sweetpotato weevils are detected in “green-tagged” or SPW-free locations. When sweetpotato weevils are detected in “green'tagged” areas, the produce is quarantined and may not be shipped to locations that do not allow “pink-tagged” sweetpotatoes. As part of the statewide SPW monitoring program, the Louisiana Department of Agriculture and Forestry (LDAF) conducts a statewide pheromone-based trapping program to monitor SPW presence in beds and fields. We used SPW presence-absence data with a GIS-based logistic regression modeling tool to assess the feasibility of developing a model for predicting SPW risk in sweetpotato beds. Using pheromone trap data from 2001–03, we performed stepwise logistic regression experiments to assess the role of various weather variables (daily mean maximum and minimum temperature, rainfall) in the occurrence of SPW in beds. Our modeling experiments showed a strong relationship of mean daily minimum temperature during the winter months with SPW occurrence in beds. In particular, a logistic regression equation developed from 2003 trap data and mean April daily minimum temperature created a spatially accurate map of SPW risk for 2002. However, the same model did not accurately predict the 2001 SPW risk. These results indicate that additional variables are needed to improve the predictive ability of the model. Spatial risk mapping can be a potentially useful tool for decision makers in choosing between risk-averse and -prone decisions.
(113) Winter-hardy Strawberries Produce without a Straw Mulch in a Severe Winter Environment
Authors: Hughes Becky R. , Dale Adam
Published: February 2019

Four winter-hardy strawberry selections and three cultivars where planted in northern Ontario in 2003 in a split-split plot trial where half the rows were mulched and half were left uncovered for the winter. Within each split plot, half the rows were sprayed for tarnished plant bugs and half were not. Yield and tarnish plant bug damage data was collected for two picking years. Two selections maintained their yields in the unmulched plots compared to the mulched plots. Yield for one of these selections was higher in the unmulched plots the first picking year and equal to the mulched plots in the second year. The remaining cultivars and selections produced less when not mulched for the winter. Except for the two selections that maintained their yields in the unmulched plots, plots where straw was applied for the winter had less tarnish plant bug damage. When the plots were sprayed for tarnish plant bugs, damage was reduced for most but not all selections and cultivars.
(116) Floral Competence of Primocane-fruiting Blackberries Prime-Jan™ and Prime-Jim™ Grown at Three Temperature Regimes
Authors: Stanton Michele A. , Scheerens Joseph C. , Funt Richard C. , Clark John R.
Published: February 2019

We investigated the response of staminate and pistillate floral components of Prime-Jan™ and Prime-Jim™ primocane-fruiting blackberry (Rubus L. subgenus Rubus Watson) to three different growth chamber temperature regimes, 35.0/23.9 °C (HT), 29.4/18.3 °C (MT), and 23.9/12.8 °C (LT). Temperature was negatively related to flower size and morphological abnormalities in floral structures were evident in 41% and 98% of the MT- and HT-grown plants, respectively. The viability (stainability) of pollen from LT- and MT-grown Prime-Jan™ flowers exceeded 70%; that of Prime-Jim™ pollen was significantly reduced (<40%) by the MT regime. Pollen in-vitro germinability was negatively influenced by temperature but was unaffected by cultivar. LT-grown pollen held at 23.9 °C retained 63% of its original germinability over a 32-hour period; the germinability of LT-grown pollen held at 35.0 °C was decreased by 97% from its original level after 16 hours. Virtually all flowers cultured under HT conditions were male-sterile, exhibiting structural and/or sporogenous class abnormalities including petaloidy, malformation of tapetal cells, and microspores or failure of dehiscence. The duration of stigma receptivity, pistil density, and drupelet set were also negatively influenced by increasing temperature; values for these parameters of floral competency among control plants were reduced by 51%, 39%, and 76%, respectively, in flowers cultured under HT conditions. Herein, flowering and fruiting parameters and presumably the yield potential of Prime-Jan™ and Prime-Jim™ were adversely affected by increased temperature. However, assessment of their adaptative response to heat stress under field conditions awaits experimentation.
(262) Screening Citrus Germplasm for Resistance to Xanthomonas axonopodis pv. Citri
Authors: McCollum Greg , Bowman Kim , Gottwald Tim
Published: February 2019

Citrus bacterial canker [causal agent Xanthomonas axonopodis pv. citri (Xac)] is a serious threat to the citrus industry. Currently, there are no effective means to control citrus canker. Our objective was to determine the resistance of selected citrus species, citrus hybrids, and citrus relatives to Xac. Our first experiment focused on determining if differences in resistance exist among 20 C. reticulata genotypes and included three other citrus species and citrus relatives (Glycosmis pentaphylla and Clausena hardimandiana). Plants were inoculated with Xac strain A either by injection infiltration or needle-prick. Our second experiment included 10 members of the genus Citrus and Poncirus trifoliata, representing a total of 31 different selections. Plants were needle-prick inoculated with both Xac strain A and Xac strain A Wellington (AW). All inoculations were done using suspensions of Xac at a concentration of 104 cfu/mL. In both experiments, there were highly significant differences among genotypes in response to inoculation with Xac. In the first experiment, regardless of inoculation method, G. pentaphylla and C. hardimandiana were found to be highly resistant to Xac, whereas C. paradisi was least resistant. In the second experiment for both Xac strain A and AW, Chinotto sour orange, Carrizo citrange, Eustis limequat, and P. trifoliata were the most resistant. Thornless key lime × Meiwa kumquat hybrids showed a range of resistance from among the most susceptible to among the most resistant. Our results expand on previous studies on resistance of citrus and citrus relatives to Xac and indicate that there may be potential for increasing resistance by breeding using selected parents.
(201) Internal Ethylene Concentration and Harvest Date Effects on Responses of Apple Fruit to 1-MCP
Authors: Jung Seok-Kyu , Nock Jacqueline F. , Watkins Chris B.
Published: February 2019

Late-harvested apple fruit generally are less responsive to 1-MCP than early harvested fruit, but the effect of harvest date on these responses can vary greatly by cultivar. Little is known about the relationships between internal ethylene concentration (IEC) and responses of fruit to 1-MCP. We have investigated the effects of 1-MCP on `McIntosh', `Cortland', and `Empire' apples in two experiments. In the first, fruit of each cultivar were picked three to five times during the normal harvest season, untreated or treated with 1 μL·L-1 1-MCP, and stored in air. Fruit IEC and firmness were then measured at monthly intervals for 4 months. In the second experiment, fruit were harvested several times during maturation, and, at each harvest, fruit were categorized into groups based on their IEC (<0.5, 0.5–1.0, 1–10, 10–50, 50–100; and >100 μL·L-1), treated with 1 μL·L-1 1-MCP for 24 hours at room temperature, and stored in air. The IEC and firmness of each fruit was then measured at set intervals during storage. Increasing IECs were associated with declining effectiveness of 1-MCP, but the individual fruit study showed that, even in high-IEC fruit, there was an initial inhibition of IEC values during storage before the IECs increased. A Lower IEC at harvest indicated a longer delay before the IEC ultimately increased. Collectively, the data show that it should be possible to determine the response of fruit to 1-MCP based on their IEC.
(42) Effects of Photoselective Shadecloths on Potted Dracaena and Anthurium Plants
Authors: Kobayashi Kent D. , Kawabata Andrew F. , Lichty Joanne S
Published: February 2019

Photoselective shadecloths that manipulate light quality may enable nursery growers to achieve desired plant growth. This ability to manage plant habit could give growers an additional nonchemical tool to improve potted plant quality. The objective of this study was to determine growth and flowering responses of potted Dracaena and Anthurium plants to four shadecloths. Dracaena deremensis `Janet Craig' and Dracaena marginata `Colorama' cane top-cuttings were placed in 70% black cinder: 30% peat moss media. Anthurium `Lola' liners were transplanted into 100% black cinder medium. Plants were grown in a greenhouse under 70% shadecloths: black, gray, red, and blue. Four months after planting, Dracaena `Janet Craig' had more new leaves under red shadecloth (10.4) compared to other shadecloths (8.9–9.3). Leaf area was less with red shadecloth (340 cm2) than other treatments (380-388 cm2). Plants under the red shadecloth had the lowest grower evaluation scores (5.4; 1 = poor, 10 = excellent) than those under other shadecloths (7.2–8.2), but all plants were considered marketable. Dracaena `Colorama' plants under red shadecloth had the greater plant height increase (20.1 cm) than those under other shadecloths (10.1–13.2 cm). Red shadecloth resulted in more new leaves (26.2) compared to other treatments (18.0–21.4). Anthurium `Lola' flower height 9 months after transplanting was less under red shadecloth (23.0 cm) than under black (33.0 cm). The number of flowers/pot was greater under red shadecloth (3.17) compared to those under other shadecloths (0.50–1.33). Flower size was greater (35.2 cm2) under red shadecloth than under black (20.0 cm2). Photoselective shadecloths may be used to nonchemically manipulate plant growth and improve the quality of potted Dracaena and Anthurium plants.
(46) Response of Container-grown Cotoneaster dammeri to Rates of Dibbled and Pre-incorporated Controlled-release Fertilizer in Three Different Media
Authors: Chong C. , Purvis P. , Lumis G. , Alam M.Z. , Roesler E.
Published: February 2019

Plug-rooted liners of cotoneaster (Cotoneaster dammeri C.K. Schneid. `Coral Beauty') were grown in 6-L nursery containers filled with three different media: 73 pine bark: 22 peat: 5 pea gravel (Medium 1); 60 pine bark: 25 peat: 15 compost (Medium 2); and 50 pine bark: 50 compost (Medium 3). Plants were fertilized with Polyon (Nutryon) 17–5–12 (17N–2P–5K) 6-month controlled-release fertilizer at various rates (0, 2.5, 4.5, 6.5, and 8.5 kg·m-3 incorporated or dibbled (placed under the liner at potting). Shoot dry weight of cotoneaster increased with increasing fertilizer rates in all three media, and was consistently higher with dibble (calculated maximum ranges, 269-362 g/plant at 6.1–7.5 kg·m-3) than with pre-incorporated (127-263 g/plant at 6.4-8.5 kg·m-3) fertilizer. Trends for root dry weight were similar with dibbled fertilizer but nonsignificant with incorporation, while those for shoot: root ratio were reversed to those for shoot dry weight. Positive correlations were observed between foliar contents of N, P, and K and shoot dry weight from both dibbled and incorporated treatments, as well as root dry weight from dibbled treatments. With incorporation, however, only foliar K was correlated with root dry weight.
(48) Substrate Media and Fertilizer Source Affect Nitrogen and Phosphorus Levels in Leachate from Container-grown Shasta Daisy
Authors: Zinati Gladis
Published: February 2019

Plugs of Leucanthemum × superbum `Becky' (Chrysanthemum `Becky', shasta daisy) were grown in #2 containers using pine bark–peat–sand or vermiculite–peat–sand (40:40:20 by volume). Containers were top dressed with either Osmocote Plus 15N–3.9P–9.9K (15–9–12) or Nutricote Plus (18N–2.6P–6.6K (18–6–8) at five rates (0, 0.5×, 1.0×, 1.5×, and 2.0×) to supply 3.9 g N per container at the recommended level (1.0×). Plants were irrigated twice a week using a cyclic irrigation regime consisting of two irrigation applications. Leachates from these containers were collected and evaluated for nitrate and orthophosphate concentrations. Irrespective of the substrate media, Osmocote Plus exhibited a higher rate of nitrogen release at the beginning of the season than Nutricote Plus. Nitrate nitrogen concentration was at least 2.5 times higher in leachates collected from media amended with Osmocote Plus than those with Nutricote Plus. Higher levels of nitrate were found in leachates collected from vermiculite-based media when compared to those from bark-based ones. Phosphate levels in leachates increased as rate of fertilizer increased and were higher in vermiculite-based media than those collected from bark-based media. Plants fertilized with Osmocote Plus were 1.7-fold greater in dry weight than plants fertilized with Nutricote Plus and were 1.2 times greater in vermiculite-based media than those in bark-based media.
(311) Teaching Assistants as a Source of Continuity and Improvement in the Classroom
Authors: Rohwer Charles L. , Wong Lynette Y. , Zlesak David C. , Cohen Jerry D.
Published: February 2019

It may seem paradoxical that a teaching assistant (TA), whose involvement in a particular class may be limited to a single semester, can provide continuity in the classroom from year to year. Improvement in TA performance from one year to the next also seems difficult to achieve under such circumstances. However, when TAs are encouraged to document classroom activities, specific TA responsibilities, and student concerns, this documentation may be useful in achieving continuity, improved TA performance, and result in a better classroom experience for the students. In addition to the benefit of documentation, TAs, in conjunction with faculty, can together reflect upon how well the objectives of specific laboratories were met. TAs can contribute to generating and documenting ideas that may be implemented to help improve student learning in the future. Each TA comes to the course with a unique collection of horticultural and teaching experiences and has the potential to aid faculty in course refinement and improvement. We explain how TA-directed documentation can provide continuity and year-to-year improvement in horticulture classrooms using our experience with HORT 3005, a required plant physiology laboratory course specifically targeted to horticulture students at the University of Minnesota.
(312) Implementing and Assesing a Bilingual Educational Program for Hispanic Nursery Workers in Ohio
Authors: Acuna Alejandra , Mathers Hannah , Case Luke
Published: February 2019

Hispanics are becoming the main source of labor in many productive- and service-oriented businesses in the United States, and the nursery industry is one example. Employers invest much time and money into employees, making the employees their biggest investment. However, the educational needs of Hispanic employees have not been adequately addressed, and no formal educational program for Hispanic workers in the nursery industry has been implemented and tested in Ohio. This project has two objectives: 1) measure the impact of a bilingual educational program containing instruction in horticulture and instruction in life skills to a Hispanic workforce, and 2) investigate which type of training is more essential to the stabilization of the Hispanic family unit, technical horticultural training, or training in life-skills. Eight nurseries throughout Ohio were selected to participate in this project. At each of the nurseries, an average group size of 15 employees was trained. Only half of this number participated in the social skills lessons to determine differences between the group who received social skills lessons and the group who did not. Three horticultural topics were selected: basic plant structure and development, pruning, and nutrition. Forty-minute lessons in Spanish with key concepts in English were prepared with the topics mentioned. Three social skills topics were selected: meeting your and your family's needs in the United States, social support in your community, and communication. In order to measure the impact of a bilingual educational program, two tests (The Rosenberg Selfeteem and Index of Family Relationship) were applied before and after the program was performed. A course evaluation was completed by each of the participants after the program was completed.
(314) Creating Videos to Enhance Student and Public Educational Opportunities in Landscape Management
Authors: Scheiber Sloane M. , Hitchcock Jennifer , Vyapari Sudeep , Osborne Lance
Published: February 2019

A series of video clips and narrated PowerPoints were developed to aid in the presentation of common horticultural techniques. To determine the most effective format for delivery of horticultural subject matter, video clips and PowerPoints were developed for three topic areas and presented to two target audience groups. Target audiences consisted of Master Gardeners (Orange and Osceola County, Fla.) and future horticulture professionals (UF Environmental Horticulture students enrolled in Landscape Plant Establishment). Upon completion of viewing both media formats, participants were asked to complete a survey. Eighty-six percent of participants completed and returned surveys. Data were sorted and analyzed for calculation of mean percent for each response sought. Results of the survey indicated that, depending upon the topic, a higher proportion (66% to 93%) of Master Gardeners preferred narrated PowerPoints in comparison to video clips. However, 60% to 70% of students preferred video clips to narrated PowerPoints. In reference to the informative nature of both videos and PowerPoints, >67% of all respondents rated both media formats between good and excellent; however, most respondents indicated new information gained was less than 40%. Factoring the costs associated with production (about $1000 per video vs. essentially no cost for narrated PowerPoints) and participant responses, narrated PowerPoints appear the best option for conveying common horticultural practices.
(309) Consumer Survey Reveals Poinsettia Cultivar Preferences for 2005
Authors: Catanzaro C. , Bhatti S.
Published: February 2019

Twenty-one cultivars of poinsettia [Euphorbia pulcherrima Willd. Ex Klotzsch] were evaluated by respondents who voluntarily completed a paper survey (n=293) at TSU. Rooted cuttings from five major U.S. suppliers were potted and grown during the preceding 4 months according to standard industry practices. Cultivars were displayed without their names for the survey, and respondents were asked to rate each cultivar on a Likert-type scale, where 1=strongly dislike and 5=strongly like. The top eight rated cultivars (mean > 3.9) were all traditional red forms, which included the new cultivar `Red Dragon', followed in descending preference by `Christmas Spirit', `Freedom Red', `Cortez Electric Fire', `Prestige Red', `Premium Red', `Novia Red', and `Candlelight'. For each cultivar, the price respondents indicated they would be willing to pay was highly correlated with the Likert-type scale score. When asked about purchases in the prior year, 89% of respondents bought at least one red poinsettia. Retail outlets and prices paid varied among respondents. Color was by far the most popular criterion respondents used to determine whether they like or dislike a cultivar, followed by foliage and price. Consistent with recent trends for value-added products, consumers indicated that they would be willing to pay significantly more for a purple-painted plant with glitter than for a white-flowered plant that was otherwise of comparable quality. These results suggest that, while red poinsettias continue to dominate the poinsettia market, niche markets exist for unique flower and foliage traits created through breeding and through enhancements such as paint and glitter.
(125) Effect of Organic Residues on Shoot and Root Growth of Apple Tree
Authors: Neri Davide , Mascanzoni Gianpaolo , Sabbatini Paolo , Zucconi Franco , Flore James
Published: February 2019

To simulate soil sickness, 1-year-old trees of `Golden Delicious' (grafted on M9 and M106) were grown in rhizotrons (1 × 1-m and 0.5-m depth) with different plant residues content, at Ravenna, Italy. Sandy loam soil was used as a substrate. Fine-grounded wood from apple and peach residues (6 kg per rhizotron) was mixed to the substrate and considered as main treatment. Mature compost (1% and 2.5% in volume) was added or not to the substrate with the organic residues and considered as subtreatment. The application of residues was localized either near the soil surface (0–25 cm) or deeper in the soil profile (25–50 cm). In each rhizotron, four trees on the same rootstock were planted and each soil treatment was replicated twice. After 2 years, the roots were accurately excavated (washing off the soil with water), and growth was measured. The presence of apple residues near the soil surface induced a 5% to 20% reduction of shoot growth. The reduction per plant dry weight was higher when trees were grafted on M106. At root level, the presence of residues increased the root migration in the search for fresh niches, enhancing root crossing and anastomosis. Both these shoot and root conditions are typical of replant diseases symptoms. The localization of apple residues in the lower part of the profile reduced the symptoms and so did the addition of compost. The peach residues did not affect shoot growth when compared to the control, but the shoot-to-root ratio was reduced, indicating a tendency to increase root migration.
(127) Use of Bioregulators to Manipulate Flowering in Apple
Authors: Schmidt Tory , Elfving Don , McFerson Jim
Published: February 2019

In three trials, 2004 crop loads were adjusted at the balloon stage of blossom development on heavily cropped whole apple trees by clipping all flower pedicels within a cluster while leaving the spur intact. Trees were adjusted to 0% crop (all flowers removed), 50% crop (half of all clusters removed), or left as 100% crop (no flowers removed). On `Cameo'/Bud.9, 400 ppm GA4+7 were applied to trees of each crop level at petal fall, 10 mm, 20 mm, or left unsprayed. At each crop load, GA4+7 marginally diminished the 2005 return bloom regardless of application timing, but the 2004 crop level was far more influential in 2005 flowering. In a second `Cameo'/Bud.9 trial, 0, 300, 600, or 900 ppm ethephon were applied to whole trees of each crop level at 45 DAFB. Ethephon generally demonstrated a rate response in improving the 2005 return bloom, but the 2005 flowering was more dramatically influenced by 2004 crop levels. On `Honeycrisp'/M.9, 300 ppm GA4+7 were applied to whole trees of each crop level at 10 mm. GA4+7 diminished 2005 return bloom at the 50% crop load, but spray effects were not as clear at the extreme 2004 crop levels. These results suggest that commercial floral inhibitors and promoters have difficulty overcoming endogenous effects of heavy or light bloom and crop in severely alternating apple trees. In a fourth trial, lightly cropped organic `Fuji'/MM.106 trees were sprayed with 0, 150, 300, or 450 ppm GA4 at petal fall, 10 mm, or 20 mm timings in 2004. The 2005 return bloom was inversely correlated with spray rates, with 10 mm showing more floral inhibition than other timings. Overall, `Cameo' was less sensitive to GA and ethephon than `Honeycrisp' or `Fuji'.
(129) Determining Maturity Indices for Eastern Black Walnut (Juglans nigra L.)
Authors: Brawner Scott A. , Warmund Michele R. , Coggeshall Mark V.
Published: February 2019

A study was conducted to: 1) evaluate the use of a durometer for determining husk softening and the date of black walnut harvest and 2) elucidate the relationship between husk hardness, kernel color and weight, and date of harvest. Thirty nuts were randomly collected weekly from mature `Sparrow', `Emma K', `Kwik Krop', and `Football' trees from 1 Sept. to 13 Oct. 2004. Husk denting, hardness, and color measurements were recorded immediately after harvest. Husk denting is the method commonly used by growers to determine the optimum time of harvest. Nuts were then hulled within 48 hours and the in-shell fresh weights were recorded. After drying under natural conditions for 5 weeks, kernel color and weights were assessed. On 15 Sept., 99% of `Sparrow' husks dented with a mean durometer value of 54. On 29 Sept., ≥99% of `Emma K' and `Kwik Krop' husks dented with mean durometer values of 63 and 68, respectively. By 13 Oct., 80% of `Football' husks dented with a mean durometer value of 74. From the first harvest date to the time of maximum denting, kernel weight and color (L*, hue values) of `Sparrow' and `Emma K' generally increased. The L* and hue values of `Kwik Krop' were inversely related to increased kernel weight over time. Kernel color of `Football' remained relatively constant as kernel weight increased over time.
(120) Comparison of Techniques for Whole Plant Sampling in Grape
Authors: Pradubsuk Suphasuk , Davenport Joan R. , Stevens Robert G. , Perry Eileen M.
Published: February 2019

Collection and estimation of root material are likely some of the greatest challenges of whole-plant sampling. As with other perennial crops, season of sample collection is also a challenge in grape whole-plant sampling. Our interest is in collecting grape whole-plant samples from an established (>25-year-old) vineyard to study plant nutrient partitioning. Before launching into routine sampling, two techniques were compared for very fine, fine, and coarse root distribution. For very fine and fine root sampling, soil cores were collected in a radial pattern around the vine trunk at eight sample points, each either 20, 60, 120 cm from the trunk or 50, 100, and 150 cm from the trunk. Roots were washed from the soil material, separated into fractions and weighed. For evaluation of techniques for sampling fine and coarse roots, roots were either excavated by tracing them from the trunk in about a 1-m3 soil volume or by extracting about the same soil volume using a backhoe and shaking the soil free of the roots. Overall, the more narrow soil core sampling gave a greater total root mass and both the tracing and backhoe methods gave similar results. In addition, pruning weight measurement is also frequently measured in grape research. We compared using the NDVI (Normalized Difference Vegetation Index) device, the “Greenseeker”™, with pruning mass to determine if this device could be used as a non-destructive measurement for grape pruning weight.
(207) Sensitivity of Two Lettuce Genotypes to Abscisic Acid during Germination
Authors: Hong Jiyoung , Cantliffe Daniel
Published: February 2019

In many lettuce (Lactuca sativa L.) cultivars, temperatures above 30 °C can inhibit germination completely. Lettuce seeds imbibed at supraoptimal temperature for 72 hours or more will not germinate even when the temperature is returned to the optimal range. Sung et al. (1998) reported that thermosensitive `Dark Green Boston' and thermotolerant `Everglades' responded to temperature at seed maturation by being able to show greatly enhanced germination at 36 °C when seeds were matured at 30/20 °C. Abscisic acid (ABA) plays an important role relative to both dormancy and germination of many seeds and may contribute to lettuce seed thermodormancy. Therefore, sensitivity of `Everglades' and `Dark Green Boston' to ABA of seeds maturated at 30/20 °C and 20/10 °C in light and dark was determined. Seeds were germinated at 20 °C and 36 °C in light and dark. All seeds of `Dark Green Boston'and `Everglades' matured at 30/20 °C and 20/10 °C germinated similarly regardless of maturation temperature and light/dark condition at 20 °C. At 36 °C in dark, both genotypes matured at 30/20 °C germinated more than those matured at 20/10 °C. `Dark Green Boston' genotypes were more sensitive to ABA (0.5, 1, 10, 50, 100 μM) during germination at 36°C in dark. When ABA was added, seeds matured at 30/20 °C germinated better than those matured at 20/10 °C, regardless of genotype. At 36 °C in light, 40% of both genotypes were inhibited at 0.5 μM ABA. At 36 °C in dark, germination of all seeds but `Everglades' matured at 30/20 °C were completely inhibited at all ABA concentrations. Thus, seed maturation temperature has an influence on lettuce seed germination at high temperature and sensitivity to ABA.
(253) `TAM Ben Villalon' and `TAM Valley Hot': Two New Pepper Cultivars from the Texas Agricultural Experiment Station at Weslaco
Authors: Crosby Kevin , Leskovar Daniel , Jifon John , Yoo Kilsun
Published: February 2019

The Texas Agricultural Experiment Station/Texas A&M University announces the release of two new open-pollinated cultivars of long chile. The first, `TAM Ben Villalon,'(TBV) is a long green chile/Anaheim type, while the second, `TAM Valley Hot,' (TVH) is a large cayenne type. Both cultivars have complex pedigrees involving TAES potyvirus resistant germplasm developed by Ben Villalon. Consequently, they exhibit resistance to some strains of tobacco etch virus when mechanically inoculated. In addition, TBV exhibits resistance to several strains of pepper mottle virus. These new cultivars out-yielded their comparable commercial cultivars, `Sonora,' and `Mesilla', when grown with drip irrigation at Weslaco and Uvalde, Texas. TBV yielded 16,632 kg/ha of green pods, compared to 14,228 kg/ha for `Sonora.' Both cultivars had similar capsaicin concentrations of 30–40 ppm on a fresh-weight basis. TBV pods are significantly heavier than those of `Sonora' due to thicker flesh. It should be useful for the green chile processing and fresh market industries. TBV may also be dried at the red stage to produce chile powder, which is very similar in quality to that of `NM 6-4.' TVH pods are not significantly different from `Mesilla' for size or weight, but contain significantly more capsaicin (670 vs. 320 ppm) when grown at Weslaco. TVH should be well-suited to the cayenne mash industry for hot sauce production due to its high heat level. Both cultivars will be distributed through commercial seed companies after receiving approval for Plant Variety Protection Patents.
(257) Evaluation and Selection of Squash Types and Cultivars for Production of Edible Squash Blossoms
Authors: Parmenter Darrin , Nagata Russell , Cushman Kent , Roe Nancy
Published: February 2019

Recently, an increasing number of restaurants in Palm Beach County, Florida, have been requesting squash (Cucurbita pepo) flowers from local vegetable growers. Typically, current field-grown squash cultivars produce a higher ratio of female to male flowers, with the emphasis on fruit production. However, a market for squash blossoms indicates a need for cultivars that produce higher numbers of consistently developing male flowers throughout the growing season. In order to evaluate male squash blossom production, 10 squash cultivars, including yellow-summer, zucchini, round, and scallop-types, and one compact-type pumpkin, were field-grown during the 2005–06 growing season. The average number of male flowers per plant by week was recorded for 7 weeks, starting when the first male flowers were identified within the entire trial. In addition to blossom counts, flower traits, such as bell height, depth, volume, and weight were also recorded. Preliminary results from the 2005 season indicate that the commercial yellow-summer squash cultivars, Mulitpik and Early Prolific Straightneck, and the zucchini cultivars, Jaguar and Raven, produced fewer male flowers on a week-by-week and total basis. The cultivar, White Bush Scallop, produced significantly more male flowers then any other entry, with an average of 9.8 male flowers per plant per week. Little or no difference was seen in bell height and depth among the 11 cultivars; however, two cultivars, Costa Romanesque and Hybrid Pam (compact pumpkin type) had significantly greater bell volumes and weights, indicating a much larger blossom size.
(21) Using Compost Sources as an Alternative to Methyl Bromide in Vegetable Production
Authors: Sanders Douglas C. , Reyes Luz M. , Monks David W. , Jennings Katie M. , Louws Frank J. , Driver Jim G.
Published: February 2019

Compost sources were used to determine long-term influence on common vegetable cropping systems (tomato, pepper, and cucumber). Three sources of Controlled Microbial Compost (CMC) (20 yd3/A) amended with fumigant Telone-C35 (35 gal/A) and Trichoderma-382 [2.5 oz/yd.3 (T-382)] were used during 3 consecutive years. Tomato showed statistic differences (1%) among compost treatments with higher total yields when CMC was combined with Telone-C35 (21%) and T-382 (8.2%). All treatments but Bio-Compost and control presented al least 25% more marketable yield per acre. No differences in fruit size were found for tomato, except for medium-size fruit when Telone C-35 was added. The CMC alone or combined with Telone C-35 and T-382 increased the total plant dry weight at least 18.6%. Pepper crop showed statistic differences with higher number of No. 1 fruit size when CMC was combined with Telone C-35 and T-382. Number of culls per acre decreased for all three compost sources, with no differences from the control. Cucumber yields differed among treatments for total and marketable yields and No.1 size fruit per acre. Best yields were achieved with CMC and when mixed with Telone C-35 and T-382. The lower numbers of culls per acre were found with Bio-Compost and Lexington sources and CMC+T-382. Total plant dry weight was increased in at least 24% when Bio-Compost or CMC compost were used alone or combined with Telone-C35 or T-382. CMC increased root knot nematode soil counts and percentage of root galling, but tended to improve root vigor in cucumbers. It seems that compost sources combined with Telone C-35 or T-382 could improve the cropping management as alternative to methyl bromide. Weed responses will also be discussed.
(23) High Tunnels for High Latitude Snap Bean Production
Authors: Rader Heidi , Karlsson Meriam
Published: February 2019

Two snap bean (Phaseolus vulgaris L.) cultivars, `Provider' and `Concesa', were planted successionally in a high tunnel in Fairbanks, Alaska (64°49'N and 147°52'W), from late May to late July. For the entire growing season, air/soil temperatures averaged 1.7 °C/1.1 °C higher in the tunnel than the field. The temperature differential was, however, largely dependent on amount of high tunnel ventilation. With tunnel ends not yet erected in May, the air temperature difference averaged 0.5 °C while in September the difference was 2.5 °C in the enclosed tunnel. On average, both cultivars flowered 4 days earlier in the tunnel compared to the contiguous open field. `Provider' had high overall yields with no significant difference between the tunnel and the field, although the tunnel did offer protection from an early frost. `Provider' produced an average of 3454 g·m-2 in the tunnel and 2860 g·m-2 in the field. Average yields of `Concesa' inside the tunnel were significantly greater (P < 0.01), with 1719 g·m-2 compared to 756 g·m-2 in the open field. `Provider' pods were larger in diameter and more fibrous than `Concesa' pods, which we concluded were of improved quality with higher soluble solids content (°Brix refractometer readings). High tunnels could be an important way to provide an advantageous production environment for high quality cultivars without sacrificing the reliability of cold-tolerant cultivars. To consistently produce high quality snap beans to meet local Alaska fresh market demands, cultivars suited for high tunnel production need to be identified.
(26) Selecting Highly Colored Bell Peppers for Fresh-market Specialty Growers
Authors: Evans William B. , Coker Christine E. , Cushman Kent E. , Horgan Thomas E. , Paridon Keri L.
Published: February 2019

Three years of trials in Mississippi have led to the naming of a Mississippi Medallion vegetable award winner for 2007, the fourth vegetable winner in the program's history. The Medallion program looks for garden crops that will perform throughout the state of Mississippi and help improve sales of plant materials to gardeners at retail. The Medallion selection process illustrates how growers and marketers, not just gardeners, can select specialty vegetables and cultivars for production and sale. Between 2003 and 2005, the Mississippi Medallion trials evaluated 11 sweet peppers with no green fruit stage for ornamental and yield value. Each site had three or four replications of all cultivars under evaluation annually with four plants per plot set out on raised beds with drip irrigation. Objective evaluation included total yield, marketable yield, fruit size, and days to harvest. Subjective evaluation included crop uniformity, pest tolerance, and appearance of the fruit based on color, uniformity, and shape. After nine trials, four cultivars were among the highest-yielding group in most trials: Mavras, Tequilla, Blushing Beauty, and Gypsy. The Medallion winner, to be announced in Fall 2006, was selected in part because it was within or near the top-yielding group, by least significant difference, in most trials. The perceived attractiveness of the mature fruit to the evaluating team and the perceived potential marketability of the cultivar moved it above the others under consideration. The reasons for not selecting other cultivars as the winner are as important as the reasons for selecting the winning cultivar. In the Medallion pepper case, these were mostly marketability concerns with the other cultivars, not yield issues, relative to that of the winner.