bluuebunny/crossref_metadata_2025 huggingface dataset:
CONTROLLED ENVIRONMENT CONSTRUCTED WETLAND TREATMENT OF GREENHOUSE DRAINAGE
Authors: Pickerell Christopher H. , Langhans Robert W.
Published: April 2024

Constructed wetlands have been used to treat many types of aqueous wastes. This innovative plant-based technology is ideally suited for use in the greenhouse horticulture industry given high levels of nutrients in irrigational runoff and drainage and the horticultural experience of greenhouse managers. Use of small-scale systems under controlled environment conditions could provide efficient and reliable year-round drainage remediation at minimal cost. Four identical 0.5m2 recirculating wetland tanks planted with Iris pseudacorus were used to treat simulated greenhouse drainage high in nitrate and other salts. Percent removal for batch-wise treatment was measured by determining concentration changes for ions in a constant volume. Nitrogen removal ranged from 87.3 to 96.7% with 7 day retention times for plant uptake experiments. Greater than 90% removal of phosphorus and potassium was achieved with 1 day and 5 day retention times, respectively. Sodium removal ranged from 13 to 60%. aluminum, boron, calcium, iron, magnesium, manganese, sulfur, and zinc were reduced appreciably within 7 days of recirculation. Treatment efficacy did not decrease over the 10 month study. Denitrification experiments using sucrose to induce anaerobic conditions showed greater than 90% nitrogen removal within 24 hours. Overall, the results were encouraging for the use of this technology in treating horticultural drainage.
EFFECT OF LEACHATE FRACTION AND WETTING AGENT ON THE SOIL NO3-N PROFILE UNDERLYING A GREENHOUSE CROP
Authors: McAvoy Richard J.
Published: April 2024

Chrysanthemums, cultivars Red Grenadine and Buckaroo, were produced in 15 cm pots in the greenhouse and fertilized with a 210 mg/l N solution at a volume of either 550 ml or 1000 ml. The nutrient solution applied to half the pots contained a wetting agent (AquaGro L), the remaining pots received no wetting agent. Soil core samples were removed, at 15 cm increments to a depth of 90 cm, from the soil profile underlying each treatment group. Leachate samples were collected and the volume and NO3-N content determined. Final and mid-term plant dry weight were determined, and the tissues (leaves and flowers) were analyzed for NO3-N and total nitrogen content. The leachate fraction (LF) from pots receiving a wetting agent (WA) was greater (p<0.05) than from pots receiving no WA (29.1% vs 26.4% respectively). However, WA did not greatly affect the amount of NO3-N in container effluent or the total NO3-N deposited on the soil underlying the crop; these were most influenced by LF. NO3-N content in the upper 15cm soil zone under pots irrigated to a high LF was higher than under the low LF pots after two weeks and by week 10 (end of the study) significant differences were measured in the 30-45 cm soil zone. At final harvest, significant differences in plant dry weight, potting medium NO3-N, and plant total N content were observed in response to both LF and WA treatments.
DESIGN AND OPERATION OF A SIMPLE HYDROPONIC SYSTEM AS A TEACHING AID FOR HORTICULTURAL SCIENCE
Authors: Garton Stephen
Published: April 2024

A hydroponic apparatus consisting of a nutrient solution reservoir, inert flotation platform containing perforated thimbles, which project through the platform was used to grow plants. The plants were started from either seeds or vegetative structures (stem cuttings, tissue cultured plantlets, leaf laminae, etc.) The apparatus is self-contained and requires no additional aeration since the design of the platform allows development of roots both in air and water. The apparatus has potential application as a research tool and in teaching plant nutrition, introductory plant science, and plant propagation.
A SURVEY OF RECENT GRADUATES OF LANDSCAPE CONTRACTING
Authors: Stearns Dan T. , Thomas Paige M.
Published: April 2024

In a survey of 42 recent graduates of the Penn State Department of Horticulture's Landscape Contracting major, 29 respondents indicated their present employment, salary range, and the type of work in which they were involved. 25 were employed by landscape contracting firms, 1 by an irrigation design firm, and 3 were attending graduate school. Salaries ranged from a low of $12,000 to $15,000, to a high of $30,000 to $35,000, with average just below $20,000. 19 were involved in landscape installation, while 14 were doing landscape design and 14 maintenance. Work in pest control and irrigation were each identified by 6 respondents. The survey requested identification of four areas important to their employment that were not adequately addressed in the curriculum. Equipment handling and repair and pest control received the greatest response. Also requested was identification of four aspects of the curriculum that were most useful to them in their employment. Design, plant identification, and construction practices received the greatest responses in this category.
WINDBREAK ESTABLISHMENT THROUGH DEMONSTRATION AND EDUCATION
Authors: Quam Vern C.
Published: April 2024

Windbreaks are an essential part of rural and urban living in the northern Great Plains. They provide protection to crops and livestock from wind by modifying windchill factors, lowering soil erosion, and conserving soil moisture. Around farmsteads and cities, benefits include energy conservation, control of snow deposits, and added aesthetic values. In urban centers windbreaks are important as aesthetic screens, living snow fences, noise barriers, and sites of air filtration.

Tree establishment on the prairies can be challenging with low rainfall and cold winter temperatures. A windbreak demonstration program began in 1989 across the state of North Dakota. The demonstration program is a joint effort between local soil conservation districts, extension service, and 275 landowners. The demonstrations were designed to compare new and traditional tree establishment techniques. The program goal is to gather data from various demonstration sites and transfer the information to land owners, thereby increasing tree survival and establishment in windbreak plantings.
ENCLAVE EMPLOYMENT AT VIRGINIA COLLEGE AND UNIVERSITY GROUNDS DEPARTMENTS
Authors: Dobbs Gerald S. , Relf Paula Diane
Published: April 2024

In 1991 and 1992, two surveys were developed and sent to 87 Virginia colleges and universities to ascertain the most effective method of employing individuals with mental disabilities within their grounds departments. There were 62 (71%) responses to the surveys. The surveys show that 21 (34%) colleges and universities have employed or currently employ individuals with mental disabilities within their grounds departments (total of 67 individuals). Currently, 11 (18%) college and university grounds departments employ 27 individuals with mental disabilities. Of these, four colleges and universities employ 20 (74%) as members of enclaves.

There were 25 individuals previously or currently employed as members of an enclave; 20 (80%) were still employed in 1992. There were 42 individuals previously or currently employed as individual employees by the grounds departments; 7 (16%) were still employed in 1992. Based on these surveys, the enclave model of employment appears to be the most successful for continued employment of individuals with mental disabilities within Virginia college and university grounds departments.
POINT OF PURCHASE BROCHURES FOR EXTENSION CONSUMER HORTICULTURE EDUCATION THROUGH RETAIL GARDEN CENTERS
Authors: Relf Paula Diane , Rogers Robin , Shelton Joyce
Published: April 2024

A series of 20 informational brochures has been produced cooperatively by representatives from five departments and the horticulture industry. These brochures focus on environmentally sound, residential landscape practices. The brochures are designed for purchase by retail garden centers, nurseries, and landscape contractors for distribution to their customers, providing educational information and freeing employee time from answering questions. An order blank has been prepared, and the material is being promoted through the Virginia Nurseryman's Association and state and regional trade shows. Topics covered are planting shrubs, planting trees, making compost, using compost, storing pesticides, choosing pesticides, pesticide labels, integrated pest management, pruning trees and shrubs, applying pesticides, healthy soil, water-wise landscaping, diagnosing plant problems, fertilizing trees/shrubs, landscaping for less in the landfill, maintaining lawns, establishing lawns, choosing turfgrass, fertilizing lawns, and selecting hand tools.
PHENOMENOLOGICAL INTERVIEWING: A USEFUL RESEARCH TOOL FOR THE HORTICULTURE INDUSTRY
Authors: Wilson Susan L.
Published: April 2024

Many research methods are available for horticulturists to use in obtaining information about a target audience. Most methods used (eg. surveys and questionnaires) are quantitative in nature in that they provide numerical data on statistical generalizable patterns.

Phenomenological interviewing is a qualitative research method which allows investigators, through open-ended interview questions, to obtain more in-depth data than traditional quantitative techniques. This research method allows investigators to understand and capture the points of view of the participants without predetermining those points of view through prior selection of questionnaire or survey categories. This research approach is used extensively in the social sciences and has implications for those working in horticulture.

To provide an understanding of the phenomenological interviewing approach as it could be used in horticulture, examples from a pilot study done on visitors to the University of Tennessee Research Gardens will be provided.
BIOTECHNOLOGY: SCIENCE AND SOCIO–ECONOMIC ISSUES
Authors: Kitto S.L. , Halbrendt C.K. , Sterling L.G.
Published: April 2024

An introductory, multidisciplinary course entitled “Biotechnology: Science and SocioEconomic Issues”, designed to introduce students to the issues associated with biotechnology, has been taught five times during the past four years. Lectures on the basic science, practical applications, ethics, regulations, and economics of biotechnology were presented by experts from academia, government and industry. In an effort to evaluate the impact of education/knowledge on acceptance of biotechnology as it relates to plants and/or animals, students were surveyed the first and last days of the semester. Survey findings will be discussed.
THE MARYLAND-DELAWARE MASTER GARDENER MANUAL, A NEW TRAINING MANUAL
Authors: Sharp Denise D. , Barton Susan S. , Traunfeld Jon H.
Published: April 2024

The Maryland-Delaware Master Gardener Manual has been printed. Twenty two chapters were written by Maryland and Delaware agents and specialists. Each chapter is designed to stand alone for use in short courses and can be purchased independently of the manual. The entire manual is in a three-ring binder. For states interested in using the Maryland-Delaware format but rewriting sections to reflect their geographic area, disk copies are available. The flexible style and content of the manual will be highlighted and appropriate ordering information will be available. The educational format offers opportunities beyond traditional master gardener classes.
A LABORATORY EXERCISE IN QUANTITATIVE COLOR DETERMINATION
Authors: Singha S. , Bible B. B.
Published: April 2024

Portable tristimulus colorimeters allow precise documentation of color of horticultural commodities and their usage in research is increasing. This laboratory exercise was designed to familiarize students with CIELAB color space coordinates and the relationship between quantitative values and visual color ratings. Students measured L* a* b* coordinates and used these values to compute and comprehend derivatives including hue angle, chroma and color difference. These concepts were demonstrated using readily available materials including bananas at different stages of maturation, apples harvested from different canopy locations, and variations in rate of oxidative browning of the flesh of apples stored at different temperature. To develop an appreciation for both quantitative and qualitative color measurements leaves of varying color were visually rated, matched to Royal Horticultural Society color charts and L* a* b* values measured with a Minolta CR-200b Chroma Meter.
MARKETING CUT-ORCHIDS TO THE TOURIST TRADE
Authors: BROWN John W. , McConnell James
Published: April 2024

Selling cut-flowers to the tourists visiting a vacation location offers an additional outlet to local growers of orchids. Advantages include a shorter marketing channel, higher local prices and the avoidance of airfreight costs and tariffs. Disadvantages include higher direct marketing costs including such items as packaging, promotion and access to the tourists, phytosanitary problems and lack of knowledge about tourists preferences for different flower cultivars and colors. This paper presents the results of a survey of the direct marketing of orchids to tourists in Honolulu, Bangkok, Phuket, Kuala Lumpur and Singapore. Pricing strategies, access to tourists and phytosanitary problems are discussed.
DO PLANTS AFFECT HUMAN BEHAVIOR IN INTERIOR SPACE?
Authors: Hillenbrand-Nowicki Cathy , Bowker Jeanette , Relf Paula Diane
Published: April 2024

Plants traditionally are used by interior designers as complementary natural components of the interior. This study attempts to identify if plants, in addition to providing visual interest, affect the spacial perceptions and behaviors of users in close proximity to them. The study was conducted in a three-level atrium built as part of an in-fill expansion project. Seating on the lowest level was used infrequently, and the total atrium was perceived as relatively unattractive. Changes in user perception and seating choices after the installation of 15-foot Ficus benjamina and 6-inch pots of Chinese evergreen plants on the lower level were measured. Findings could be a useful tool in redefining the use of plants in interior design and a tool for market development for the interior plantscape industry.
SUSCEPTIBILITY OF DRY EDIBLE BEANS TO LEAFHOPPER INJURY
Authors: Lindgren Dale T. , Coyne Dermot P.
Published: April 2024

Twenty-two lines of dry edible beans, Phaseolus vulgaris, were rated for leafhopper (Empoasca fabae) injury in 1991 in field plots near North Platte, NE. Lines were re-evaluated in 1992 in a split-plot design in protected (insecticide applied) and unprotected treatments. There were significant differences for yield, leafhopper counts, and leafhopper injury between 1) protected and unprotected treatments, 2) lines and 3) for protection × lines interaction. There were significant correlation coefficients between insect number (-0.44**) and plant injury (-0.46**) with yield in the unprotected treatments, but no significant correlations in the protected treatments. Average insect counts on three trifoliate leaves on the 22 lines ranged from a low of 2.3 to a high of 32.0 in the unprotected plots. There was a significant difference in seed size and seeds/pod but not for pods/plant for protected versus unprotected treatments. The studies suggest leafhoppers have a much greater preference for some bean lines than others. This should be a consideration when breeding/selecting bean lines for locations where leafhoppers are prevalent.
TENDRILS AS AN ALTERNATE TISSUE SOURCE FOR CHROMOSOME VISUALIZATION
Authors: Yadav R.C. , Grumet R.
Published: April 2024

Cytogenetic analysis of plants is most frequently performed using root tip squashes. However, roots are not always readily available. As an alternative approach to verify the ploidy level of our transgenic melon (Cucumis melo) plants we tested the possibility of using meristematic tissue at the tip of growing, young tendrils. A procedure has been developed to visualize the chromosomes in melon and cucumber. The cytological technique included fixation of young tendrils for 24 hours in acetoalcohol (1:3) or carnoy's fluid followed by hydrolyzing in IN HCl for 10 min at 60°C. The tips were then squashed in 0.5% acetocarmine. The procedure yielded well separated chromosomes of the two species. We are now testing whether this technique can also be utilized for visualizing chromosomes of other tendril bearing plants e.g. peas, grapes.
COMPARISON OF SCREENING METHODS FOR EVALUATING RESISTANCE OF SWEETPOTATO CLONES TO STREPTOMYCES IPOMOEA.
Authors: Wolters Petra J. , Collins Wanda W.
Published: April 2024

Streptomyces ipomoea is the causative agent of a destructive disease of sweetpotato called Streptomyces soil rot or pox. Efforts to incorporate resistance to S. ipomoea into new cultivars have been limited by the need to make evaluations in naturally infested fields, which are seldom large or uniform enough for such evaluations. In this study three different methods for evaluating clones in the greenhouse or laboratory were compared: 1) root slices dipped into a S. ipomoea suspension, 2) terminal vine cuttings planted in a vermiculite-broth carrier containing aerial mycelia and spores of the pathogen, and 3) one internode long, rooted cuttings planted in tissue culture boxes containing the previously mentioned carrier. Preliminary results using five sweetpotato clones indicated that correlations between data from the three methods were moderate to high (r=0.31 to 0.99). Correlations found between data from method 1 and 2 were higher (r=0.65 to 0.99) than between data from either method 1 and 3 (r=0.41) or method 2 and 3 (r=0.31 to 0.68). These results suggest that method 3 may be less reliable for evaluating resistance of sweetpotato clones to infection with S. ipomoea than method 2 or 3.
GENETIC VARIABILITY FOR EATING QUALITY ATTRIBUTES IN SWEET CORN.
Authors: Azanza F. , Juvik J.A.
Published: April 2024

Some of the primary physiological attributes of sweet corn eating quality that have previously been associated with consumer preference are kernel moisture content, pericarp tenderness (the force required to puncture the pericarp), sugar content and the concentration of phytoglycogen, a water soluble starch, and dimethyl sulfide (DMS), a volatile aromatic compound. This experiment was conducted to evaluate a set of 24 sweet corn inbreds with three endosperm mutations (4 sugary1, 7 sugary enhancer, and 13 shrunken2) for variation for these characteristics over two years on fresh ears harvested at 18 and 22 days after pollination (DAP). Significant genotypic variability was observed among inbreds, as well as between harvest stages for all the characteristics. Kernel moisture ranged from 69 to 79%, pericarp tenderness from 49 to 165 g/mm2, sugar content from 125 to 496 mg/g, phytoglycogen from 4 to 212 mg/g and DMS from 4 to 65 μg/g of dry matter at 18 DAP. From 18 to 22 DAP ears, averaged over the inbreds, were found to decrease 7% in kernel moisture, 25% in tenderness, 17% in sugar and 40% in DMS content, and increase 32% in phytoglycogen. Genetic differences among the inbreds accounted for most of the total variability for the attributes analyzed. This suggests that development of genotypes with improved eating quality can be accomplished.
A NEW PURPLE HULL PEA
Authors: Morelock T.E. , Motes P. , Davis D.R.
Published: April 2024

Southernpeas Vigna unguiculata are a popular crop in the southeastern U.S. They are grown in home gardens, as a fresh market vegetable and are an important processing crop to both canners and freezers. While several types of southernpeas are grown, pinkeye purple hull types are by far the most important type for processing. The breeding line Arkansas 87-435 is bush, early maturing, concentrated set pinkeye purple hull type that has been widely tested in the southeastern U.S. It was entered in the southern cooperative trial for 3 yrs. and has been evaluated by major processors in the region. This line is being released to fill the need for an early maturing concentrated set pinkeye purple hull type that is adaptive to machine harvest and narrow row cultivar.
A PROCEDURE FOR OBTAINING ADDITIONAL REPULSION PHASE LINKAGE INFORMATION IN F2 FAMILIES
Authors: Chaparro Jose , Warner Dennis , Crane Barbara , O'Malley Dave , Sederoff Ronald
Published: April 2024

F2 families provide less linkage information than testcross families for markers in repulsion phase orientation. However, generation of testcross families is often more difficult than the generation of F2 families in self-pollinating species. A procedure was developed for determining map position for markers within repulsion phase linkage groups generated in F2 families of peach. A genomic map consisting of homolog specific linkage groups of RAPD markers was generated in an F2 family obtained from NC 174RL × `Pillar'. Numerous markers were identified that mapped to either allele of the Gr (red leaf) locus. The relative position of markers in these homolog specific groups was determined by characterizing the segregation distortion of the repulsion phase RAPD markers in a sample of 96 progeny homozygous recessive grgr. Repulsion phase markers within 20cM of gr deviated from a 3:1 segregation ratio. Individuals homozygous recessive for both gr and repulsion phase markers were then genotyped for coupling phase RAPD markers to facilitate generation of a graphical genotype. This graphical genotype information was used to determine orientation of the homolog specific linkage groups and to determine map order within the repulsion phase linkage group.
BORON AFFECTS LOWBUSH BLUEBERRY FRUIT SET AND YIELD
Authors: Smagula John M.
Published: April 2024

Five lowbush blueberry (Vaccinium Angustifolium Ait.) clones with leaf tissue boron levels below 20 ppm were selected in a commercial lowbush blueberry field in Washington County, Maine. Four 2.4 M2 treatment plots established on each clone received a foliar spray of Solubor at 0, 200, 400 or 600 ppm boron in September. The terminal 3.8 cm of stem, sampled in November, had increased concentrations of boron with increasing rates of boron application. Boron sprays also increased boron leaf tissue concentrations in July of the crop year. Ten stems with four flower buds were tagged in each treatment plot to determine the effect of boron treatments on fruit set and berry size. Fruit set was the same for each bud, but the number of blossoms and fruit per bud was greater on buds below the terminal. Yield increased in response to boron application up to 400 ppm, due to increases in fruit set, berry number and berry size of three of the five clones.
THE COMMON AND DIFFERENT RESPONSES OF DORMANT GRAPEVINE BUDS TO CHEMICALS FROM VARIOUS GROUPS.
Authors: Nir Gil , Lavee Shimon
Published: April 2024

Several groups of chemicals were tested for their effect on grapevine bud dormancy. Single-node cuttings were treated with hydrogen cyanamide and several of its derivatives, the respiratory inhibitors DNOC and azide, the alcohols 2-chloro ethanol and ethanol alone or in combination with cyanamide, the peroxide H2O2, Various sulfhydryls, the heribicides 3-amino triazol and paraquat and two inhibitors of polyamine biosynthesis. Although in each of these groups were active dormancy breaking agents which could be related to defined pathways, it became clear that the activity of these chemicals is specific and only partialy dependent on the common chemical configuration. It seems that in most cases the degree of activity could be related to their relation with peroxide scavenging activity or level of oxidation in the bud tissue.
DEVELOPMENTAL STAGES OF TABLE GRAPES IN NORTHERN MEXICO.
Authors: Gardea Alfonso A. , Mancilla R. , Obando R. , Madero E. , Byerly K.F.
Published: April 2024

An ampelographic collection was introduced to Comarca Lagunera, México in 1968. This work presents seven-year data of phenological evaluations on Cardinal, Queen, and Ribier mature vines, which are representatives of early, mid-, and late harvest seasons, respectively. Variables evaluated were the intervals required for a) budbreak (start to end), b) final budbreak to 50% bloom, c) 50% bloom to 50% vérasion, d) budbreak to vérasion, and e) soluble solids accumulation (SSA) after vérasion during the last two seasons. No significant differences were found for a), with averages around 213 Heat Units (HU, base temperature 10C). No differences were found either for b), with means close to 212 HU. However, differences (p≤0.001) were found for the interval bloom to vérasion with HU values for Cardinal, 720±32; Queen, 989±63; and Ribier, 1012±43. This interval accounted for the differences found in the whole cycle budbreak-vérasion. In the two-year study on SSA no differences in rates were found within genotypes, but among them. Therefore, our results suggest that -mainlythe bloom-vérasion period is responsible for defining the harvest season, along with budbreak timing and ripening rate.
INVERTASE IN FLOWER BUDS AND MATURE FLOWERS OF SNAPDRAGON
Authors: Campos Ricardo , Miller William B.
Published: April 2024

Invertase (EC 3.2.1.26) is an important enzyme in carbohydrate metabolism. This sucrose hydrolyzing enzyme was extracted and partially purified from mature flowers stored at -75° C, and fresh flower buds of snapdragon (Anthirrinum majus L.). Purification steps were precipitation with ammonium sulfate (25% to 80%) and two column chromatography fractionations: DEAE-Sephacel followed by Sephacryl S-200. An acid invertase was found in flowers of `Maryland White' and also in flower buds of `Potomac White'. Maximum enzyme activity was obtained at 55° C and a pH range from 4.2 to 5.0 for both enzymes in flowers and flower buds. Compared to citrate, acetate, citrate phosphate, and succinate buffers at pH 4.6 and 0.1 M increased enzyme activity by two fold.
FLOWER INITIATION AND DEVELOPMENT OF PRIMULA GROWN AT INCREASED ROOT-ZONE TEMPERATURE
Authors: Karlsson Meriam G. , Hanscom Jan T.
Published: April 2024

Plants of Primula malacoides Franch `Prima Carmine Red' and Primula vulgaris Huds. `Danova Lemon Yellow' were grown for 5 weeks after transplant in root growth chambers maintained at 16, 20 or 24C. Germination and seedling development occurred at 16C, 16 hours photoperiod and 5.8 mol· day-1m-2 (100 μmol· s-1m-2). The location for the root growth chambers and the continued plant development after the root temperature treatment was a greenhouse at 15 ± 3C and 16 hours at an average 5.8 mol· day-1m-2. Both flower initiation and flowering were first recorded for P. malacoides plants grown in the root growth chamber at 16C. The observed time from transplant to flower initiation was 28 days and to the first open flower 76 ± 5 days for the plants grown with 16C root zones. The number of leaves and shoots on P. malacoides plants showed an increasing nonsignificant trend with increasing root temperature. P. vulgaris may respond differently than P. malacoides to increased root temperature.
COMPARATIVE STUDY OF TEMPERATURE INTEGRAL AND PFD ON VEGETATIVE GROWTH OF EPIPREMNUM AUREUM AND X FATSHEDERA LIZEI
Authors: Christie C. Bruce , Warrington Ian J. , Stanley C. Jill
Published: April 2024

The relationships between temperature and light on vegetative growth of the foliage house plants Epipremnum aureum (Linden and Andre) Bund, and X Fatshedera lizei (Guillaum) were investigated in a controlled environment study during the exponential growth phase. Responses were examined under conditions with a constant day temperature (30°C) in combination with constant night, split-night or sliding night temperatures with means of either 15° or 20°C. Two PFDs of 150 and 320 μmol·s-1·m-2 were included in each temperature treatment. Growth parameters (including dry matter increase, shoot elongation rate and leaf production rate) were all influenced by species but not by each temperature profile within the same temperature integral (ie all growth responses were directly related to mean night temperature). Growth rates were highest under the high PFD conditions but dry weight accumulation per unit of PFD was markedly higher at low PFD than at high PFD. The optimum temperature for vegetative growth of Epipremnum aureum was higher than that for X Fatshedera lizei and Epipremnum aureum was particularly sensitive to temperatures below 10°C.
THE EFFECTS OF LONG DAYS AND SHORT DAYS ON GROWTH OF SEVERAL SPECIES OF HERBACEOUS PERENNIALS FOLLOWING VERNALIZATION OF PLUG-GROWN SEEDLINGS
Authors: Engle Beth E. , Cameron Arthur C. , Heins Royal D.
Published: April 2024

Achillea filipendulina `Cloth of Gold', Astilbe arendsii, Campanula carpatica `Blue Clips', Echinacea purpurea `Bravado', Gaillardia grandiflora `Goblin', Lavandula angustifolia `Munstead Dwarf', Oenothera missouriensis, Rudbeckia fulgida `Goldstrum' plugs were stored at 5C for 0, 2, 4, 6, 8, and 10 weeks under a 5 μmol· s-1· m-2 PPF. Sample plants were removed and planted in 10 cm pots and placed in a 19C, constant temperature greenhouse under short-day or long-day photoperiods. Long-days were provided with night-break lighting from 10:00 p.m. until 2:00 a.m. by incandescent lamps. In Achillea, Campanula and Gaillardia, only terminal buds grew in the long-day photoperiod while both terminal and lateral buds grew under short-days. Development of Astilbe, Echinacea, Oenothera, Rudbeckia was minimal under short-days compared to that under long-days. Lavandula in the early treatments remained vegetative, short, and compact under short days, whereas plants elongated and flowered while grown under long days. Longer durations of storage shortened the time from potting to flowering for Lavandula.
LEAF, STEM, AND FLOWER CHARACTERISTICS OF ROSA HYBRIDA L. UNDER DIFFERENT CO2 CONCENTRATIONS
Authors: Meinke Troy T. , Hopper Douglas A. , Story Virginia S.
Published: April 2024

Two greenhouses received ambient CO2 and two were enriched between 1000 and 1200 ppm CO2 when vents were closed. Two-year-old Rosa hybrida L. `Royalty', `Emblem', and `Samantha' plants growing in each house were pinched 20 Oct. and 28 Dec. 1992 for Christmas and Valentine's Day crops. All temperature set points were 22C/17C day/night. At flowering, 5 shoots from each bench location were destructively sampled for stem diameter, stem length, and fresh and dry weights of stem, leaves, and flower bud.

At flowering for the Christmas 1992 crop, shoots in the enriched houses tended to have larger stem, leaf, and flower fresh weights, and larger stem diameters. Analysis of variance found stem lengths of combined cultivars to be longer (p < .05) in the CO2 enriched houses. Mean stem lengths were 68.8 cm and 63.9 cm for flower stems in CO2 enriched and ambient houses, respectively. Dry weight data from the Christmas crop, and results from the 1993 Valentine's crop will be presented.
CORRELATION OF POINSETTIA GRAFT UNION DEVELOPMENT WITH TRANSMISSION OF THE FREE-BRANCHING AGENT
Authors: Ruiz-Sifre Gerardo , Dole John M. , Richardson Paul E. , Kahn Brian , Ledford Joanna
Published: April 2024

Euphorbia pulcherrima Willd. ex. Klotzsch `Eckespoint C-1 Red' (C-1) a restricted-branching poinsettia and `CB' a free-branching graft-hybrid were approach grafted. Graft unions were removed from poinsettia grafted pairs at 0, 5, 10, 15, 20, 25 or 30 days after grafting for anatomical study and the portion below the graft union was allowed to regrow. By 10 days after grafting, C-1 receivers showed increased branching and C-1 and CB parenchyma cells were actively dividing, producing new parenchyma cells (callus). Callus connected CB donors and C-1 receivers and may have allowed the transmission of the branching agent by 10 days after grafting. Parenchyma cells differentiated into nodules for the formation of new cambium by 25 days after grafting. CB donors and C-1 receivers were interconnected by new vascular tissue after 25 days of graft formation. CB donors may have controlled the differentiation of vascular tissue of the graft union.
TEMPERATURE, IRRADIANCE, AND COOLING TREATMENT LENGTH AFFECT PELARGONIUM × DOMESTICUM FLOWERING.
Authors: Erwin John E. , Engelen-Eigles Gerard
Published: April 2024

Rooted cuttings of Pelargonium × domesticum B. cv `Vicki' were placed in controlled environment chambers maintained at 2, 6, 10 or l4C. Irradiance levels were 0, 200 or 350 μmol s-1 m-2. Plants were rotated among chambers at 0900 and 2100hr (12hr photoperiod) daily to yield 16 day/night temperature (DT/NT) treatments. Plants were removed from treatment chambers after 3, 4.5 or 6 weeks and were placed in a glasshouse maintained at 12 ± 2C. Data were collected at anthesis on node number from initiation of the cooling treatment to the base of the inflorescence, total flower number per plant and branch number. Node number increased exponentially from 16.1 to 22.3 as the average daily temperature which plants were cooled at increased from 2 to 14C. Total flower number per plant increased from l05 to 127 as NT increased from 2 to 10C. Flower number was unaffected by DT. Flower number per plant increased from 97 to 127 and node number decreased from 17.6 to 16.4 as irradiance levels increased from 0 to 350 μmol s-1 m-2. Flower and branch number increased as the length of the cooling treatment increased from 3 to 6 weeks. Node number was unaffected by the length of the cooling treatment
CELLULASE ACTIVITY IN COLEUS
Authors: Wang Yalai , Craker Lyle E.
Published: April 2024

The cellulase in leaf abscissing abscission zones of coleus was observed to have an isoelectric point of 4.7. Ethylene promoted activity whereas IAA inhibited activity in the abscission zones as compared with untreated controls. The enzyme could be purified 130 fold with a combination of gel filtration, and anion exchange and affinity chromatography. Both silver-stained SDS-PAGE and cellulase activity-stained native PAGE exhibited 2 bands in the finally purified protein, suggesting two isozymes. The 2 protein bands with molecular weights of 56 and 62 kD were apparently monomers. A test of cellulase activity at various pHs indicated high level of activity at pH 5 and pH 7.2. Activity increased with an increase in reaction temperature to 50°C. Both isozymes appeared necessary for abscission in coleus.
INTERACTION BETWEEN IRRADIANCE AND PHOTOPERIOD ON ANTIRRHINUM MAJUS L. FLOWER INITIATION.
Authors: Erwin John E. , Schwarze Debra J.
Published: April 2024

Antirrhinum majus L. cv `Winchester' seedlings (first true leaf stage) were placed in controlled environment chambers maintained at 20C under 8, 10, 12 or 14 hr photoperiods for flower induction. Seedlings were grown at irradiance levels of 240, 315, 380 or 460 μmol s-1 m-2 within each chamber. Plants were removed after 7, 14 or 21 days and were placed in a glasshouse maintained at 20 ± 2C under natural photoperiod and irradiance levels for flower development. Data were collected on flower number and number of nodes below the first flower when all flowers were visible on the inflorescence. Node number decreased from 67 to 43 nodes as photoperiod increased from 8 to 14 hrs. Increasing irradiance hastened flowering on plants grown under 8-12 hr photoperiods only and had no effect on flower number. Flower number increased from 23 to 30 as photoperiod length increased from 8 to 14 hrs. Node number decreased from 57 to 44 nodes and flower number increased from 22 to 31 flowers as the time of treatment increased from 7 to 21 days under the 14 hr photoperiod. Time of treatment had no effect on node number or flower number when plants were grown under 8 or 10 hr photoperiods.
COMPETITIVE EFFECT OF TURFGRASS AISLES ON PRODUCTION AND QUALITY OF FIELD-GROWN ZINNIAS
Authors: Stevens Alan , Gast Karen
Published: April 2024

Field production of specialty cut flowers has become of increasing interest during the last few years. A production system consisting of permanent bed planting as opposed to planting as a single row crop is common. Aisle management is an important component of this system. A vegetative aisle cover affords product quality enhancement and improved labor and equipment utilization throughout the field. This study compared the competitive effect on zinnia yields and flower quality between bare ground and five turfgrass species planted in the aisles. Plots surrounded by bare ground had higher yields and better quality than the turfgrass plots. Annual ryegrass had the greatest competitive effect on flower production and quality of the five turfgrass species studied.
INVERTASE INHIBITOR IN TOMATO FRUIT
Authors: Pressey Russell
Published: April 2024

Tomatoes contain a high level of the enzýme invertase which hydrolyzes sucrose to glucose and fructose. A protein that inhibits invertase has been found in tomatoes, suggesting that it may be involved in the regulation of invertase activity. A procedure was developed for the separation of the inhibitor from invertase based on the higher stability of the inhibitor in acid solutions. Residual invertase in acid extracts of pericarp tissue was removed by anion exchange chromatography. The inhibitor has been purified to homogeneity by subsequent gel filtration and cation exchange chromatography. It is a heat-stable protein with a mol wt of 18,000. The reactivity of the inhibitor with tomato invertase is pH dependent with maximum inhibition at pH 4.7 and no inhibition at pH 3.5 and 6.2. The result is double pH optima for invertase activity in the presence of the inhibitor. The inhibitor is effective on invertase from potatoes and may be similar to the invertase inhibitor found in potatoes.
QUALITY EVALUATIONS OF WATERMELON CULTIVARS
Authors: Collins J. K. , Perkins-Veazie P. , Maness N. , Cartwright B.
Published: April 2024

The postharvest quality of one seedless and four seeded watermelon cultivars was studied. Melons were evaluated for ascorbic acid content, sugar composition, soluble solids concentration, lycopene concentration, color and sensory qualities. Ascorbic acid values were higher for `Allsweet' and `Jubilee' melons compared to the other cultivars. `Black Diamond' had higher fructose levels than `Calhoun Gray', `Jubilee' or `King of Hearts'. Soluble solids concentration was highest for `Allsweet' and lowest for `Black Diamond' melons. `King of Hearts' fruit had the highest lycopene content which was correlated with chroma color values. Untrained taste panelists preferred `Calhoun Gray', `Jubilee', and `Allsweet' for taste compared to `Black Diamond' melons.
INFLUENCE OF CLOMAZONE HERBICIDE ON POSTHARVEST QUALITY OF PROCESSING SQUASH AND PUMPKIN
Authors: Weston L.A. , Barth M.M. , Harmon R. , Zhuang H.
Published: April 2024

Six processing squash and pumpkin cultivars (Marrow, Howden, Butternut, Buttercup, Golden Delicious, and Turk's Turban) were direct-seeded into replicated plots treated with selected pre-emergence herbicides. Treatments included application of varying rates of clomazone, an inhibitor of carotenoid biosynthesis. Problems associated with bleaching and whitening of fruit, and storability have been reported in squash and pumpkins treated with labelled rates of clomazone. Therefore, this study was initiated with FMC to evaluate herbicide treatment effects on cultivars during 6 wk postharvest storage. Replicated samples were stored at 18°C and quality was evaluated at each storage interval (0, 2, 4, 6 wk). Quality was assessed by total carotenoid and reduced ascorbic acid contents, color retention, peroxidase and lipoxygenase activities, % soluble solids, and fatty acid composition. Results indicated differences in levels of tissue bleaching, carotenoid contents, enzyme activities among cultivars over time. Treatment with high rates of clomazone resulted in reduced tissue carotenoid content, with certain cultivars more affected than others.
DIFFUSIVITY OF WATER VAPORS IN POTATO TUBERS.
Authors: Solomos Theophanes , Abdul-Baki Aref A. , Bunce James A.
Published: April 2024

It is known that, in a number of plant tissues, the diffusivity of water vapors is larger than that of CO2. We have measured the water potential of both intact potato (Solomon tuberosum, cv. Russet Burbank) tubers, using a Wescor due point probe, and tissue slices, using the liquid exchange method. The water potential measured by both methods was similar. The results show that the diffusivity of water vapors is larger than that of CO2. The difference in diffusivity between CO2 and water vapors is attributed to a simultaneous loss of water through diffusion and surface evaporation. The results indicate that the contribution of the latter mechanism to water loss is more significant than simple diffusion.
FIELD PERFORMANCE OF TRANSGENIC TOMATOES WITH REDUCED PECTIN METHYLESTERASE ACTIVITY
Authors: Tieman Denise M. , Kausch Kurt D. , Serra Delila M. , Handa Avtar K.
Published: April 2024

We have introduced an antisense pectin methylesterase (PME) gene into Rutgers tomato to elucidate its role in fruit development and ripening. In greenhouse trials tomato fruits from transformant 37-81^ homozygous for the antisense PME gene ripened normally and contained higher levels of soluble solids than wild-type Rutgers fruits (Tieman et al. (1992) Plant Cell 4:667-679). Field trials of transgenic 37-81^ homozygous and azygous for the antisense PME gene and wild-type Rutgers were conducted during the summer of 1992. Field grown fruits from homozygous 37-81^ plants have significantly higher levels of soluble solids and total solids and a higher fruit pH than Rutgers or 37-81^ azygous fruits. Average fruit weight did not differ significantly in the three genotypes, but 37-81^ (homozygous) plants had a higher total fruit yield than Rutgers or 37-81^ azygous plants. Plant fresh and dry weights did not differ significantly among the three plant types.
SIMULATED TRANSPORT AND POSTPRODUCTION OF LILIES
Authors: Nell Terril A. , De Hertogh A. A. , Leonard Ria T. , Barrett James E.
Published: April 2024

Simulated transport (ST) of `Aristocrat', `Polka' and `Horizon' flowering Lilies was conducted at 2, 7 or 13C for 3, 6 or 9 days, then plants were held at 21±2C at 10 μmol ·s-1 ·m-2 for postproduction evaluations. Number of open flowers was reduced for `Polka' at ST of 9 days at 13C, while `Aristocrat' and `Horizon' were unaffected. Differences in individual flower longevity were found between the first and last open flowers. First open flower longevity was reduced by ST of 9 days and last open flower longevity was reduced by ST of 7 and 13C for both `Polka' and `Horizon'. ST for 9 days at 13C increased flower diameter and decreased whole plant longevity.

Exp. 2. Postproduction evaluation of `Stargazer' and `Aristocrat' were conducted using 18, 19.5 or 21C at 8 or 16 μmol ·s-1 ·m-2. Number of open flowers was unaffected by treatments, while flower longevity and whole plant longevity were greatest at 18C.
MACROPHYLLA DECLINE: A NEWLY DESCRIBED DISORDER IN CITRUS
Authors: Taylor Kathryn C. , Meiners Michael
Published: April 2024

Macrophylla decline was observed primarily in lemons on the macrophylla rootstock (Citrus macrophylla, Wester). This disorder is characterized by foliar zinc deficiency symptoms with zinc accumulation in trunk phloem above the bud union. Trees show symptoms of twig dieback and are less thrifty in appearance compared to the same cultivars on other rootstocks. These characteristics are very similar to a citrus disorder of humid citrus production regions, citrus blight. Citrus blight affects the more vigorous rootstocks (a characteristic of Macrophylla) such as the extremely blight susceptible rough lemon rootstock. In the humid regions, macrophylla is considered somewhat susceptible to blight. Experiments are currently underway to assess the water conductivity of xylem in trees on macrophylla and to screen for the presence of citrus blight specific proteins.
FREEZING TOLERANCE OF SALT-AND COLD-ACCLIMATED CITRUS AND PONCIRUS SPECIES
Authors: Tozlu Ilhami , Moore Gloria A. , Guy Charles L.
Published: April 2024

It has been previously established that cold acclimation increases freezing tolerance in Citrus. Because both salt and cold streeses are osmotic stresses, salt application may also increase freezing tolerance. Freezing tolerance of salt treated `Pineapple' orange (C. sinensis [L.] Osb.), large pink pummelo (C. grandis [L.] Osb.), and Pomeroy trifoliate orange (Poncirus trifoliata [L.] Raf.) seedlings is being examined. LT50s for each species under our freezing conditions were established by subjecting nonacclimated and cold acclimated plants to temperatures ranging from 0 to -19°. Seedlings were treated with various concentrations of NaCl (0, 40, 80, and 150 mM) under cold-acclimating and nonacclimating conditions for 2 months, then subjected to freeze stress and examined for ability to recover. In an initial trial, pummelo seedings treated with 40 and 80 mM salt under cold-acclimating conditions displayed an increase in freezing tolerance, while exposure to any level of salt decreased freezing tolerance of sweet orange and trifoliate orange seedlings.
`KEITT' MANGO STORAGE UNDER CONTROLLED AND MODIFIED ATMOSPHERE.
Authors: Gustavo González A. , Báez-Sañudo R. , Siller-Cepeda J. , Gardea A. , Vázquez C.
Published: April 2024

México is an important mango producer. During its marketing is necessary to maintain fruit quality for long periods to access distant markets. Modified (MA) and controlled (CA) atmospheres are used in some tropical fruits to attain these goals. In this work, we evaluated Keitt mangoes quality under CA (low O2 ≤0.3%) and MA with three low density polyethylene (LDP) films (100, 200 and 300 mils) during six days. CA fruit treated and LDP packed were stored for 30 days at 10C. Every three days, samples from CA and MA were evaluated, and every ten days a lot of treated fruits were transferred to 20C to determine fruit quality changes. We found that both, CA and MA (using LDP) delayed weight and firmness losses. Fruits kept a good appearance with a significative delay of the maturity process. However, fruit packed with 200 and 300 mils LDP developed a fermented taste after 10 days at 10C. Our conclusions suggest that these treatments prolong marketing and storage life of “Keitt” mangoes.
ASCORBIC ACID AND QUALITY LOSSES OF `VALENCIA' ORANGE STORED ON THE TREE.
Authors: Siller-Cepeda Jorge , Báez-Sañudo R. , Angulo M. , Durón J. , Nuñez J. , Bringas E. , Báez M.
Published: April 2024

On-tree storage of Citrus has been a common practice to prolong marketing season, even for those fruits reaching legal maturity. Under this situation, fruit quality losses are dependent upon the length of stored period. On this work, we evaluated the effect mat on-tree storage had over the level and form of ascorbic acid, as well as, the quality of fruit harvested at different intervals after legal maturity. Treatments consisted on harvesting fruits at seven different dates beginning on 18 March (legal maturity) and on 6 May, 21 May, 23 June, 17 July, 28 August and 14 September, 1992. Quality variables evaluated were: diameter, ring thickness, weight, color (chroma, hue and value), firmness, pH, soluble solids, tritatable acidity, juice content, and ascorbic acid content and form. Fruit weight fruit and pH increased with harvesting date. Color in its three aspects decreased, indicative of value loss, change from yellow to green, and defined chroma colors. Citric acid drop drastically, and although degree Brix was almost constant, the Citric acid/Brix increased from 15 to 38, representing fruit taste loss. Ascorbic acid decreased, while its oxidized form increased with successive harvesting dates.