bluuebunny/crossref_metadata_2025 huggingface dataset:
Greenhouse Pesticide Application Safety Training
Authors: Panter Karen L.
Published: December 2018

Between Dec. 1992 and July 1993, 13 greenhouse operations took part in on-site training programs concerning pesticide application safety. Each program involved a pre-quiz, post-quiz, presentation of two videotapes, discussion, session evaluation, and follow-up evaluation 1 month after each session. A total of 253 Colorado greenhouse employees participated in the programs, which fulfilled the employee training requirements for the Occupational Safety and Health Administration's Hazard Communication standard concerning hazardous materials in the workplace. Quiz scores increased from the pre- to the post-program quiz, from 17.3 to 22.1 points out of a possible 27. Post-program evaluations indicated that the vast majority of respondents either “agreed” or “strongly agreed” that (percentages in parentheses): “the training program will be helpful” (85%), “I understand hazardous materials better” (81%), “the training videos helped understanding” (84%), and “I would like the training done regularly” (79%). Follow-up evaluations showed that most “agreed” or “strongly agreed” that (percentages in parentheses): “I have used at least one new safe handling practice” since the program (55%), and “I plan to use more” safe handling practices (82%). This method of instructing employees about hazardous materials would be applicable to others interested in safety issues.
A Classroom Laboratory Exercise to Demonstrate Seed Priming
Authors: Duray Sharon A. , Davies Fred T.
Published: December 2018

A laboratory exercise is outlined and discussed for seed priming, or osmoconditioning. The exercise was developed using an easily constructed and inexpensive seed-priming system. A variety of horticultural seeds can be used to give students experience and exposure to some of the benefits of seed priming. Seed germination data usually can be obtained within 6 to 8 days, depending on the species used. The laboratory may be modified to stress various features of seed priming, including priming agents, optimal concentrations, and ranges of germination temperatures.
A Laboratory Exercise for Axillary Shoot Proliferation using Ajuga reptans
Authors: Preece John E. , Huetteman Carl A.
Published: December 2018

This exercise was developed for a plant propagation course to demonstrate, in a short time, the four stages of micropropagation, the effects of cytokinin concentrations, and the differences between adventitious and axillary shoots. Greenhouse-grown stock plants were brought into the laboratory, and 4- to 5-cm-long tips of runners were surface-dis-infested for 15 min in 0.5% NaClO with 1 ml of Tween 20/liter, followed by two 5-min rinses in sterile water. Working in the open laboratory near the bases of pairs of lit Bunsen burners, students placed either single-node or shoot tip explants (2 cm long, five replications) onto MS medium with 0, 1, or 10 μM BA. Cultures were in-cubated in parafilm-sealed culture tubes on open laboratory benches. Axillary shoots grew regardless of concentration of BA, and explants on medium with 10 μM BA produced the most callus and adventitious shoots. Microshoots were rooted and ac-climatized under mist in the greenhouse. This exercise can be performed in an open laboratory without the use of laminar flow hoods, specialized sterilizing equipment, or supplemental lighting.
A Laboratory Exercise to Demonstrate Direct and Indirect Shoot Organogenesis from Leaves of Torenia fournieri
Authors: Bridgen Mark P. , Hadi Masood Z. , Spencer-Barreto Madeleine
Published: December 2018

A laboratory exercise on direct and indirect organogenesis from leaf explants is presented for students of plant tissue culture or plant propagation. Torenia fournieri, the wishbone flower, is used for this laboratory exercise because the in vitro production of adventitious shoots from Torenia is easy to control, seeds are easy to obtain, and plants are easy to grow. Direct shoot organogenesis results from leaf explants without an intervening callus phase, and indirect shoot organogenesis is possible after 4 to 6 weeks of callus production from leaf explants. The basal medium for all forms of organogenesis contains Murashige and Skoog (MS) salts and vitamins, 30 g sucrose/liter, and 7 g agar/liter at pH 5.7. To obtain direct shoot organogenesis, leaf explants should be placed on the MS basal medium with 1.1 μM (0.25 mg·liter-1) 6-benzylaminopurine (BAP) and 0.25 μM (0.05 mg·liter-1) indole-3-butyric acid (IBA). If leaf explants are placed on MS medium with 2.3 μM (0.5 mg·liter-1) 2,4-dichlorophenoxyacetic acid (2,4-D), callus formation will occur. Callus can be subcultured onto a MS medium with 8.88 μM BAP (2.0 mg·liter-1) plus 2.5 μM IBA (0.5 mg·liter-1) for indirect shoot organogenesis to occur.
Foliar Elemental Analysis of Southern Highbush, Rabbiteye, and Highbush Blueberries in the Southern United States
Authors: Clark John R. , Creech David , Austin Max E. , Ferree M.E. “Butch” , Lyrene Paul , Mainland Mike , Makus Don , Neuendorff Liz , Patten Kim , Spiers James M.
Published: December 2018

Highbush (Vaccinium corymbosum L.), rabbiteye (V. ashei Reade), and southern highbush (Vaccinium spp.) blueberries grown at seven locations in six southern states were sampled in 1988 and 1989 to determine foliar elemental levels among blueberry cultivars and types. Across locations, elemental levels of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, and Al were similar for highbush and southern highbush types. Rabbiteye elemental levels were different from highbush and southern highbush for N, P, K, Ca, S, Mn, Cu, and Al. Rabbiteye blueberries appear to have different foliar levels, and may require species-specific standards for nutritional monitoring of plantings.
The Kearney Agricultural Center Perpendicular “V” (KAC-V) Orchard System for Peaches and Nectarines
Authors: DeJong Theodore M. , Day Kevin R. , Doyle James F. , Johnson R.S.
Published: December 2018

This paper describes a moderately high-density orchard training system (1000 trees/ha) developed at the Univ. of California's Kearney Agricultural Center for peach and nectarine trees grown on standard rootstocks. This two-leader system was developed to increase production during the early years of the orchard while minimizing specialized management operations during orchard maturity. Early selection of two primary scaffolds oriented perpendicular to the tree row is recommended during the first season of growth. During subsequent years, summer and dormant pruning requirements are similar to the standard open-vase system grown in California. Because of the uniform and relatively simple tree structure, individual scaffolds, rather than whole trees, can be used as functional units for crop load management.
A Window Into Below-ground Growth of Landscape Trees: Implications for Transplant Success
Authors: Harris Roger , Bassuk Nina L. , Whitlow Thomas H.
Published: December 2018

Root and shoot phenology were observed, and root length within rootballs were calculated for Fraxinus pennsylvanica Marsh. (green ash), Quecus coccinea Muenchh. (scarlet oak), Corylus colurna L. (Turkish hazelnut), and Syringa reticulata (Blume) Hara `Ivory Silk' (tree lilac) trees established in a rhizotron. Easy-to-transplant species (green ash and tree lilac) had more root length within rootballs than difficult-to-transplant species (Turkish hazelnut and scarlet oak). Shoot growth began before root growth on all species except scarlet oak, which began root and shoot growth simultaneously. Fall root growth ceased for all species just after leaf drop. Implications for tree transplanting are discussed.
Taxus Populations and Clippings Yields at Commercial Nurseries
Authors: Hansen Robert C. , Cochran Kenneth D. , Keener Harold M. , Croom Edward M.
Published: December 2018

A natural product known as taxol has been approved by the FDA for treatment of ovarian and breast cancers. In addition, preliminary clinical studies have shown encouraging results when using taxol to treat melanomas, lung, head, and neck cancers. Ornamental yews have been identified as a potential renewable source of taxol and related taxanes. Commercial nurseries were surveyed during Summer and Fall 1991 as a basis for estimating populations of Taxus cultivars currently growing in the United States. Clippings of selected cultivars were sampled from nursery fields in Ohio and Michigan to estimate expected clippings yields as a function of cultivar and cultivar age. More than 30 million Taxus plants were reported to be grown by the 19 major nurseries that responded to the survey. About 88% of all Taxus plants reported in the survey were grown in the three-state area of Ohio, Michigan, and Pennsylvania. Taxus × media `Densiformis', `Hicksii', and `Brownii' were found to be grown by nearly all nurseries in the survey; more than half grew T. × media `Wardii' and T. cuspidata `Capitata', while other well-known cultivars seem to have been specialties of one or two nurseries. Annual clippings yields on a dry-weight basis (db) ranged from ≈20 g/plant to 140 g/plant. Expected yields were found to be very dependent upon plant age and cultivar. Taxus × media `Hicksii' appeared to be the most ideal ornamental yew that could provide a renewable source of taxol because of immediate availability and potential for mechanical harvesting of upright clippings. An estimated 3000 to 4000 ovarian cancer patients could be treated annually with the taxol currently available for extraction from T. × media `Hicksii' clippings.
The Effect of Orchard Design on Almond Fruit Set
Authors: _ _ , Espada J.L. , Felipe A.J.
Published: December 2018

Low levels of fruit set were measured in a commercial almond [Prunus amygdalus Batsch, syn. Prunus dulcis (Mill.) D.A. Webb] orchard during 3 years. Low sets may be attributed mostly to orchard design, as cultivars are distributed in contiguous rows where pollen interchange among different cultivars is not facilitated. An appropriate orchard design and proper bee management are essential for commercial yields in self-incompatible almond cultivars.
Planting-date Effects on Early maturing Pigeonpea in a Short-season Environment
Authors: Marsh Lurline
Published: December 2018

Determinate, photoperiod-insensitive genotypes of pigeonpea [Cajanus cajan (L.) Millsp.] have production potential for the short growing seasons of the temperate region. A 3-year field study was conducted to determine the effect of three planting dates on the growth and development of pigeonpea in Missouri. Seeds of four genotypes, ICPL 87 Isolation (85k), ICPL 85010, ICPL 85024, and ICPL 8304 were planted 1 May (PD1), 15 May (PD2), and 1 June (PD3). Germination of the earliest-planted seeds was <32%, but increased to an average of 57% for PD3. Earliest-planted seeds generally took the longest time to first flowering and harvest. The initial fresh pod harvest of plants from PD1 and PD2 overlapped. The earliest harvest was produced by ICPL 85024 from PD2 at 91 days (1300 degree-days C) after planting. Over the 3 years, the genotypes in PD1 produced the highest fresh pod weights (205-357 g/plant) and longest pods. Those of PD3 produced the lowest pod weight. The seed number per pod (three to four) and weight of 100 seeds (16-22 g) were generally unaffected by planting dates.
Description of a Crop Growth Model for the Management of Supplemental Lighting in Greenhouses
Authors: Carrier Michel , Gosselin André , Gauthier Laurent
Published: December 2018

A dynamic management strategy for supplemental lighting in greenhouses was developed. It makes use of a plant growth model and of a rule-based decisionmaking protocol within the framework of a generic greenhouse climate management software system. The model, an adapted version of SUCROS87, tracks plant growth and predicts dry weight production based on measured or estimated values of light intensity, temperature, and CO2 concentration. A set of logical predicates (rules) implements the strategy's behavior. Optimization of lamp use was conducted as a function of economic criteria that enable a comparison between the additional income associated with yield increases due to supplemental lighting and incurred cost increases. Although the model is not perfectly reliable in its predictions, the system can be used to simulate the effect of changes to economic parameters on the decisions of the management strategy. The dynamic strategy described here differs from conventional supplemental lighting scenarios in the sense that it increases the length of the period of supplemental lighting when the daily solar light integral is low, and reduces or eliminates the use of supplemental lighting when the weather forecast predicts that the daily solar light integral will exceed plant requirements.
Herbicides Available for Commercial Cabbage Producers during 1965-94
Authors: Hopen Herbert J.
Published: December 2018

Through cooperation of state agricultural research stations, U.S. Dept. of Agriculture-Cooperative States Research Service (USDA-CSRS) Interregional Project Four (IR-4), manufacturers and grower organizations, new herbicide labels for cabbage have been granted recently. Labels for the herbicides consist of national, regional, and state need and state emergency use labels. These herbicides provide adequate choices of labels for cabbage producers in the major commercial production areas. Starting with only three herbicides available in 1965 to a choice of 10 herbicides in 1994, growers can be more effective in control of weeds in cabbage.
A Model for Dry Bean Yield Loss Due to Rust
Authors: Lindgren Dale T. , Eskridge Kent M. , Steadman James R. , Schaaf Daniel M.
Published: December 2018

Severity of rust (Uromyces appendiculatus) and yield of dry edible beans (Phaseolus vulgaris L.) were recorded for 9 years in west-central Nebraska in fungicidal efficacy trials. A weighted analysis of covariance was used to estimate yield loss due to rust. The model fit the data well (R2=0.94), and the slope over all years had a 19 kg.ha−1 decrease in yield for each 1% increase in severity of rust. Yield response within years occurred only through reduction of rust for most fungicide treatments.
Copper Hydroxide Affects Root Distribution of Ilex cassine in Plastic Containers
Authors: Gilman E.F. , Beeson R.J.
Published: December 2018

The root : shoot ratio for Ilex cassine L. grown 7 months in copper-treated containers was less than in nontreated containers. There was less dry weight for roots <5 mm in diameter in copper-treated containers than in nontreated containers in the outer 1 cm of the rootball. Dry weight of roots >5 mm in diameter within the rootball were not affected by copper hydroxide treatment. Coating the interior of a plastic container with cupric hydroxide eliminated coarse roots (> 5 mm in diameter) and significantly reduced fine root weight from the outer 1 cm of the rootball. Fine roots inside the rootball did not replace fine roots lacking in the outer 1 cm.
Comparing Productivity in Greenhouse Tasks of Individuals with and without Mental Disabilities
Authors: Eddy Robert T. , Belfiore Phillip J.
Published: December 2018

Many studies have described the ability of individuals with mental disabilities to learn vocational tasks commonly performed in greenhouses, and a survey of horticulture employers reports a favorable perception toward the work habits of these individuals. Productivity data are not available from these studies, however. We sought to quantify productivity of individuals with and without mental disabilities performing entry-level greenhouse tasks. Information on ten tasks was compiled from surveys of four vocational centers with greenhouse production and six commercial greenhouses. Individuals with mental disabilities produced at rates of 46% to 192% of corresponding commercial rates, with seven often skills performed. above 75% of the commercial rate. The results from this pilot study suggest that individuals with mental disabilities can achieve satisfactory productivity in real work settings. While significance was not achieved due to limitations of the study, the results provide a baseline for further study by other researchers. The practical significance of these findings can be judged by trainers and employers.
Influences of Foliage Plants on Human Stress during Thermal Biofeedback Training
Authors: Coleman Cammie K. , Mattson Richard K.
Published: December 2018

Twelve 20-minute thermal biofeedback sessions were conducted with 26 university students. Visual stimuli were provided by a living foliage plant, a life-sized color photograph of that plant, or a metal stool (control). Of the participants, 38% responded positively to the presence of a live plant or plant photograph, while 23% showed lower stress in the control room. Stress reduction, as indicated by higher skin temperatures, occurred within the first 5 to 8 minutes of a 20-minute thermal-biofeedback session. A nonplant visual stimulus was not part of the experiment. The results are not intended as comparative, nor do they attribute unique or superior effects to plants. Due to the small number of participants, no significant results were obtained, but the trends were important and are being reported to help further research in this area.
High Relative Humidity after Ethylene Gassing is Important to Banana Fruit Quality
Authors: Blankenship Sylvia M. , Herdeman Robert W.
Published: December 2018

Bananas were held at 18C in all possible combinations of 65%, 75%, or 95% relative humidity (RH) before and after gassing with ethylene. Peel color, fruit firmness, starch loss, compression injury to peel and pulp, and overall peel scarring were measured. Peels were greener and the fruit were slightly firmer when fruit were held in the higher humidity combinations, particularly when the humidity was high after gassing with ethylene. Starch loss was not different among humidity treatments. Overall peel scarring was about twice as severe with 65% RH compared to 95% RH during the ripening phase. Low humidity before ethylene gassing had little effect on overall scarring. There were some instances where humidity had a significant effect on compression injury; high humidity caused less injury, but the effect was inconsistent.
A Climatic Approach to Pecan Scab Control
Authors: Sparks Darrell
Published: December 2018

Pecan (Carya illinoinensis) scab was evaluated following unusually extended rains in 1994. Strengths and weaknesses of a variety of scab management practices were studied in five orchards, Scab control was more effective on trees with adequate sunlight exposure than in dense orchards or with fungicide applied after rain than by preset intervals. Triphenyl tin hydroxide, a nonsystemic fungicide, was most effective when applied within 24 h after rain; but, the systemic fungicide, propiconazole, was effective when applied within 6 days after rain. Fungicides must be applied consistently after rain for maximum scab control.
Medium and Fertilization Affect Performance of Potted Dendrobium and Phalaenopsis
Authors: Wang Yin-Tung
Published: December 2018

Dendrobium Linnapa `No. 3' plants were potted one per 1.75-liter pot with large or small fir bark with or without 30% peatmoss (by volume before mixing). Plants in each medium were fertilized at each or every third irrigation with 1 g·liter−1 of 20N-8.6P-16.6K fertilizer. Neither medium nor fertilization frequency affected flowering date of the first pseudobulb. Adding peatmoss to both types of bark resulted in taller first pseudobulbs. Peatmoss in the large bark promoted the production of more inflorescences and flowers (20) compared to the bark alone (11). Constant fertilization promoted the early emergence and development of the second pseudobulb and resulted in more inflorescences and flowers (21) than intermittent fertilization (12). Vegetatively propagated Phalaenopsis Taisuco Kochdian were planted in 0.5-liter pots with 1) equal volumes of no. 3 perlite, Metro Mix 700, and charcoal (PMC); 2) 100% large fir bark; or 3) 40% medium fir bark, 20% peatmoss, 10% each of no. 3 and no. 2 perlite, 10% vermiculite, and 10% ParGro rockwool (RM). Plants in PMC produced twice the number of new leaves and 1.5 -fold more leaf area than those in the large bark. PMC and RM resulted in similar shoot weights, but the latter enhanced flower count due to more lateral inflorescences. Most (80%) of the roots on plants in the bark were hanging out of the pots, whereas nearly all the roots remained in the pots with PMC. Although medium had no effect on flowering date, flowers on plants produced in PMC and RM were 10% larger than in those on plants produced in bark.
Composition of Four Potato Cultivars in Relation to Cold Storage and Reconditioning
Authors: Okeyo James A. , Kushad Mosbah M.
Published: December 2018

`Atlantic', `BelRus', `Kennebec', and `Superior' potatoes (Solarium tuberosum L.) were evaluated for ascorbic acid, soluble protein, and sugar content (reducing and nonreducing) at harvest, after 6 weeks of storage at 3C, and after 2 weeks of reconditioning at 25C. At harvest, ascorbic acid and soluble protein contents varied among the cultivars, with `Superior' containing the highest ascorbic acid (154 mg/100 g dry weight) and soluble protein content (46.4 mg·g−1 dry weight). Cold storage resulted in a drastic reduction (±50%) in ascorbic acid content in all four cultivars. Ascorbic acid also decreased during reconditioning of tubers, but the reduction was less than during cold storage. In contrast, soluble protein contents were not influenced significantly by cold storage or reconditioning, except for `BelRus' and `Kennebec', which had less protein after reconditioning. At harvest, glucose, fructose, and sucrose contents were at similar levels in all cultivars, except for fructose in `Kennebec', which was more than 2-fold higher. `Kennebec' also had a significantly lower specific gravity than the other cultivars. However, unlike the other cultivars, reconditioning of `Kennebec' tubers did not affect its specific gravity or total sugar content. Data suggest that `Kennebec's' poor processing quality may have resulted from a combination of low specific gravity and high total sugar content.
Consumers' Preference for Insecticide-free Pumpkins in Eastern Kansas
Authors: Olson Denise L. , Nechols James. R. , Marr Charles W.
Published: December 2018

A survey conducted at farmers' markets in eastern Kansas showed that more consumers purchased pumpkins for jack-o-lanterns than for cooking. One to four jack-o-lantern pumpkins are purchased annually per consumer. Whether or not the pumpkins are treated with insecticides to control squash bugs and regardless of their intended use, consumers preferred U.S. no. 1 grade, which sell at the higher retail price of $0.33/kg. At least 90% of the consumers surveyed would pay 20% more than the retail price for insecticide-free pumpkins. About two-thirds of those polled would pay 30% more. Cost-benefit data indicate that the higher prices consumers would pay may not be sufficient for growers to produce insecticide-free pumpkins economically using only biological control. However, if biological control is integrated with host-plant resistance, the higher prices may be sufficient for growers to produce insecticide-free pumpkins.
The Effectiveness of Using Workshops to Change Audience Perception of and Attitudes about Xeriscaping
Authors: McKenney Cynthia , Terry Robert
Published: December 2018

Current estimates indicate that half of the water consumed in the urban environment is used to maintain landscapes. With this volume of water expended each year in landscape care, competition for the limited water exists. Xeriscaping reduces water demands while retaining an attractive landscape; however, the image of xeriscaping is frequently poor. In this project, workshops were conducted to measure audience perception, attitude, and knowledge of xeriscaping as a result of this type of activity. The effectiveness of the workshops was determined using pre- and postworkshop surveys. The audience's perception and attitude” toward xeriscaping improved in every area. The audience's general knowledge about the principles of xeriscaping increased significantly for almost every concept. Promotional aspects of attracting a large and diverse audience was the area needing further enhancement.
Horticulture Information on the Internet: Cyberhorticulture on the Information Super Highway
Authors: Burger David W. , Katcher J.B. , Lange Nathan E. , Saenz Jose L. , Sherman Scott P. , Stoutemyer Mark R.
Published: December 2018

Graduate students in horticulture at the Univ. of California, Davis, spent an academic quarter learning how to use the Internet and World-Wide Web (WWW) to access and collect information. The collected information was organized and placed on the WWW where it is available to anyone with access to the Internet.
Plants and CO2: A Quick and Easy Laboratory Exercise
Authors: Marler Thomas E. , Discekici Haluk M.
Published: December 2018

A laboratory exercise is outlined in which breath is used as the source for elevating CO2. Single-plant enclosures are constructed by placing containers with stem cuttings within clear bags for maintaining high humidity during root initiation. These enclosures provide a restricted atmosphere in which elevated CO2 is adequately confined. The materials are inexpensive and readily available. The procedure is rapid, with results obtained in as few as 7 days. The increase in canopy and/or root growth as a result of elevated CO2 may be observed visually by younger audiences, or may be measured and analyzed in a manner dependent on the age group. The exercise generates an abundance of discussion and may be used to lead into many lectures on plant physiology, horticultural crop production, or global concepts of CO2 and the plant kingdom.
A Heat Unit Accumulation Method for Predicting Cucumber Harvest Date
Authors: Perry Katharine B. , Wehner Todd C.
Published: December 2018

The use of a previously developed model for predicting harvest date in cucumber production systems is described. In previous research we developed a new method using daily maximum temperatures in heat units to predict cucumber harvest dates. This method sums, from planting to harvest, the daily maximum minus a base temperature of 60F (15.5 C), but if the maximum is >90F (32C) it is replaced by 90F minus the difference between the maximum and 90F. This method was more accurate than counting days to harvest in predicting cucumber harvest in North Carolina, even when harvest was predicted using 5 years of experience for a particular location and planting date.
Field Assessment of a Fiber Optic Spectral Reflectance System
Authors: Blazquez C.H. , Nigg H.N. , Hedley L.E. , Ramos L.E. , Simpson S.E.
Published: December 2018

Spectral reflectance measurements were taken from immature and mature leaves of `Rio Red' grapefruit `McCarty' grapefruit `Minneola' tangelo, `Satsuma' mandarin, `Dancy' tangerine, `Nagami' oval kumquat, and `Valencia' orange from 1330 to 1530 hr 1 day at the Florida Citrus Arboretum, Division of Plant Industry, Winter Haven, Fla. A PS-1000 spectrometer was used with fiber optic cables and a lens source (visible range of the spectrum 400-800 sun) coupled with a tungsten halogen light source. A data acquisition card was connected to a notebook computer with a SpectraScope computer program for processing and data storage. Immature and mature leaves of `Minneola' tangelo had greater percentage reflectance in the 500-800 sun range than the other cultivars and leaf ages measured. More detailed information was obtained with the PS-1000 than with conventional spectrometers. The slope of the citrus spectral curves in the 800 nm range was not as sharp as conventional spectrometers, but had a much higher reflectance value than those obtained with a different spectrometer. The system used here was convenient to transport and use in the field and produced clear, interpretable data.
Somatic Embryogenesis versus Organogenesis in Cucumber: Developing a Laboratory Exercise
Authors: Reichert Nancy A. , Zimmerman Nancy J.
Published: December 2018

Fourteen commercial cucumber (Cucumis sativus L.) cultivars were screened on media designed to induce somatic embryogenesis and shoot organogenesis. Cotyledon explants from mature dry seeds and 7-day-old seedlings also were compared for responses. Seven cultivars (Burpless F1Hybrid, Burpee Hybrid II, Cross Country, Picklebush. Sweet Delight, Tasty Green, and Yard Long) responded best for individual regeneration ability. Within the somatic embryogeneais regeneration protocol, `Picklebush' responded better than most other cultivars, while `Burpless F1 Hybrid' responded best in shoot organogenesis. Also, within each type of regeneration, the developmental stage of the cotyledon explants appeared to influence regeneration ability.
Release Rates of Soluble and Controlled-release Potassium Fertilizers
Authors: Broschat Timothy K.
Published: December 2018

Release rates for 13 commercially available soluble and controlled-release K fertilizers were determined in sand columns at 21C. Potassium chloride, KMgSO4, and K2CO3 were leached completely from the columns within 3 or 4 weeks. Osmocote 0N-0P-38.3K, Multicote 9N-0P-26.7K, the two S-coated K2SO4 products, and Nutricote 2N-0P-30.8K Ty 180 all had similar release curves, with fairly rapid release during the first 20 to 24 weeks, slower release for the next 10 to 12 weeks, and virtually no K release thereafter.
New Insights in Plant Breeding Efforts for Improved Salt Tolerance
Authors: Shannon Michael C.
Published: December 2018

The lack of improvement for salt tolerance has been attributed to insufficient genetic variation, a need for rapid and reliable genetic markers for screening, and the complexities of salinity × environment interactions. Salt tolerance is a quantitative characteristic that has been defined in many ways subject to changes with plant development and differentiation; thus, assessing salt tolerance among genotypes that differ in growth or development rate is difficult. Salt tolerance also varies based on concentrations of major and minor nutrients in the root zone. Plant growth models may provide a method to integrate the complexities of plant responses to salinity stress with the relevant environmental variables that interact with the measurement of tolerance. Mechanistic models have been developed over the last few years that are responsive to nitrogen or drought stress but not to salinity stress. Models responsive to salinity stress would provide insights for breeders and aid in developing more practical research on the physiological mechanisms of plant salt tolerance.
Injecting Chemicals into Drip Irrigation Systems
Authors: Clark Gary A. , Smajstrla Allen G.
Published: December 2018

The injection of chemicals into irrigation systems is discussed in terms of injection systems, concentration injections, bulk injections, quantity of chemicals to be injected, injection system calibration, and injection periods. Sufficient clean-water flush time should be scheduled to purge irrigation lines of injected chemicals unless it is desired to leave that particular chemical in the irrigation system for maintenance purposes. Chemical injection rates vary with desired chemical concentration in the irrigation water, concentration of the stock solution, volume of chemical to be injected, and duration of each injection. All injection systems should be calibrated and maintained in proper working order. This information is presented to assist irrigation system designers and operators with chemigation system design, scheduling, and management.
Pest Management in the United States Greenhouse and Nursery Industry: IV. Weed Control
Authors: Norcini Jeffrey G. , Garber Melvin P. , Hudson William G. , Jones Ronald. K. , Chase Ann. R. , Bondari Kane
Published: December 2018

Members of the American Association of Nurserymen and the Society of American Florists were surveyed as to their use of herbicides and nonchemical alternative weed control practices for 1993. Glyphosate was the top-ranking herbicide among the total of 37 reported, in terms of number of respondents and estimated total amounts of active ingredients applied. It was used by all but two of the respondents that used herbicides in their operations. Oryzalin was the top-ranked preemergent herbicide, and was second only to glyphosate in number of respondents and amount of active ingredient applied. The highest estimated use in amounts of active ingredient applied was in the southeastern (43% of total) and north-central (27% of total) regions, nearly two to three times the estimated use in the northeastern or western regions. However, there were only about 50% more respondents in the southeastern or north-central regions compared to the other regions. About 56% of herbicide active ingredients used were in field sites, 22% in container sites, 19% in perimeter areas, and 3% in green-houses. Large firms (annual sales more than $2,000,000) used the greatest estimated total amount of active ingredients, while small firms (annual sales more than or equal to $500,000) tended to use nonchemical alternatives the most. Nearly all respondents used handweeding or hoeing as part of their weed control program. Mowing was used by 84% of the respondents, 71% used tractor cultivation, and 66% used mulches (includes gravel and black plastic). Alternative methods were rated as somewhat effective to very effective by 65% or more of the respondents who used them.
Sustainable Agriculture on the Internet: Practical Uses
Authors: Auburn Jill Shore
Published: December 2018

The Internet has experienced tremendous growth recently. The number of users, the amount and diversity of information available, and exposure in the mass media have all grown rapidly. Several authors recently have asserted that the media reports are overblown and that Internet is not as useful as most reports portray. Agricultural professionals need to assess whether or not the cost of using the Internet (in learning time as well as money) will benefit them in terms of increased knowledge and productivity. This paper describes current use of the Internet to answer practical questions from research and education, using a survey and practical examples from sustainable agriculture.
AGNPS: A Software Program for Assessing Nonpoint Source Pesticide Pollution
Authors: Pantone Dan J. , Young Robert A.
Published: December 2018

Nonpoint-source pesticide pollution from horticultural and other agricultural activities is a primary factor determining the quality of surface water. A menu-driven, interactive pesticide transport submodel has been developed for the agricultural nonpoint-source (AGNPS) pollution model. AGNPS simulates the surface transport of pesticides, sediment, and water from the headwaters to the outlet in a stepwise manner so that an assessment can be made at any point within a watershed boundary. The model can be used by farmers, agricultural extension agents, agrichemical industry workers, or researchers to develop agricultural activities that minimize the surface transport of pesticides. This user-friendly pesticide transport model is available at no cost to users through the Internet.
Integrated Decision Support System: Potential for Horticulture
Authors: Ikerd John E.
Published: December 2018

Farming operations must be environmentally sound and economically viable if they are to be sustainable over time. Thus, farmers of the future must balance environmental and economic concerns in making management decisions. An integrated farm decision support system, PLANETOR, has been developed to help farmers balance soil loss, water-quality risks, production efficiency, and profitability in the farm planning process.
Practical Use of Time Domain Reflectrometry for Monitoring Soil Water Content in Microirrigated Orchards
Authors: Parchomchuk P. , Berard R.G. , Tan C.S.
Published: December 2018

We have found time domain reflectrometry (TDR) to be a rapid and effective method of measuring soil water content (SWC) in microirrigated orchards, particularly in applications where many sites are monitored frequently. With simple modifications to commercially available systems, it has been possible to measure up to 100 sites per hour. TDR SWC measurements have been successfully applied for scheduling irrigation and for in situ determination of SWC characteristics. The determination of plant water use from changes in SWC of microirrigated trees, however, requires that a sufficient number of probes be used to detect the spatial distribution of water within the root zone. Due to water redistribution in the soil following an irrigation, measurements made near drip emitters depend highly on the time after irrigation that the measurement is made. It is therefore important to be consistent in the timing of SWC measurements relative to irrigation events if the effects on SWC of different irrigation management practices are to be compared.
Nitrogen and Phosphorus Requirements for Rockwool-grown Cucumbers Trained with a Double-stem Method
Authors: Schon M.K. , Compton M. Peggy
Published: December 2018

Four experiments were conducted from 1992 to 1994 to determine the concentrations of N and P required to maximize yields of rockwool-grown cucumbers (Cucumis sativus `Vetomil') trained with a double-stem method. Concentrations of N and P in rockwool slabs were monitored throughout growth of greenhouse-grown cucumbers. The onset and duration of nutrient depletion in the slabs were related to cucumber yield. In Expt. 1, treatment-1 plants received a two-step solution containing N at 90 and 175 mg·L−1 during successive growth phases, while treatment-2 and -3 plants were grown with N at a constant 175 or 225 mg·L−1. Phosphorus was provided at 50 mg·L−1 in all treatments. Treatment 1 was excluded from Expt. 2. In Expts. 3 and 4, plants were grown with N at 225 or 275 mg·L−1 and P at 75 mg·L−1. Onset of N and P depletion (to <10 mg·L−1) in the growing slabs occurred during the early fruiting stage of cucumber, 1 to 8 days before first harvest. The duration of N and P depletion decreased, and cucumber yields increased with increasing N and P concentrations. When plants were grown with N and P at 275 and 75 mg·L1, respectively, N was depleted in the growing slabs during only one experiment and then for only 4 days, and slab P concentration remained >10 mg·L1. Therefore, under Florida conditions, when growing cucumbers in rockwool using a double-stem training technique, N and P should be provided at 275 and 75 mg·L−1, respectively, to minimize depletion of these nutrients from the growing medium.
Writing in Horticulture: A Course to Help Graduate Students Write More Effectively
Authors: Decoteau Dennis R.
Published: December 2018

A one-credit course, Writing in Horticulture, was developed and taught to graduate students in the Dept. of Horticulture at Clemson Univ. The course focused on discussion and explanation of the philosophies and methods of writing in the horticulture field. Discussions included a review of writing mechanics, types of writing and audiences, examples of exemplary writings, editing and reviewing, and examples and methods of professional correspondence. Real-life writing experiences were emphasized. Hands-on activities included writing and reviewing peer manuscripts and grant proposals. Three original written works were completed by the end of the semester: 1) a popular press article, 2) a grant proposal (maximum three pages long), and 3) an abstract for a manuscript published previously in a scientific journal.
Teaching Horticulture and Native American Agricultural Traditions: An Annotated Bibliography
Authors: Meyer Mary Hockenberry , Barker Anna F.G.
Published: December 2018

A bibliography of references on Native American agricultural traditions is proposed to integrate horticulture into classroom teaching with a multidisciplinary approach. Five teaching themes are given as examples of using the references to incorporate horticultural activities across diverse disciplines such as mathematics, history, language arts, economics, and social sciences.
Forcing Method and Time of Rootstock Shoot Removal Affect Growth of Containerized Citrus Nursery Trees
Authors: Williamson J.G.
Published: December 2018

I conducted an experiment to determine the effects of time of rootstock shoot removal on growth of citrus nursery plants forced by bending and lopping. `Hamlin' orange [Citrus sinensis (L.) Osb.] budded on Carrizo citrange [C. sinensis (L.) × Poncirus trifoliata (L.) Raf.] and Cleopatra mandarin (C. reticulata Blanco) seedlings were grown in 2.8-L plastic pots and forced by bending or lopping the rootstock shoots. For Carrizo plants, rootstock shoots were removed 0, 21, 36, 170, or 235 days after forcing. For Cleopatra plants, rootstock shoots were removed 0, 11, 21, 36, 170, and 235 days after forcing. Bending and lopping with rootstock shoots remaining attached for 36 days after forcing resulted in greater nursery tree growth (scion, root, and wholeplant dry masses; scion length; and leaf area) than when rootstock shoots were removed the day of forcing. Growth of scion leaves (both rootstocks) and stems (Cleopatra) was greatest at a rootstock shoot removal time (RSRT) of 36 days after forcing. However, root and whole plant dry masses increased as RSRT increased up to 235 days after forcing. These results suggest that roots continue to be a major sink for rootstock photosynthates of bent or lopped plants during periods after the first scion growth flush. Proportionally greater root growth occurred on plants forced by bending or lopping when rootstock shoots were left attached for more than the usual 4 to 5 weeks after forcing.
Potential Use of Sucrose as a Feeding Deterrent for Frugivorous Birds
Authors: Socci Anne M. , Pritts Marvin P. , Kelly Mary Jo
Published: December 2018

A mixed cultivar blueberry planting was treated with a concentrated sucrose solution before fruit ripening and after episodes of rain during the harvest season. Fruit losses due to birds were monitored throughout the season in this planting and in the same cultivar in a separate nontreated planting ≈200 m (650 ft.) away. Fruit loss to birds was ≈50% greater in the nontreated planting over the first 3 weeks of harvest. In addition, bird activity was monitored between 0600 and 0700 hr on two occasions in each planting during the early harvest season. Bird activity was many times higher in the nontreated planting. These observations suggest that sucrose should be tested more widely for potential activity on bird feeding behavior.
Using Ultra-high Carbon Dioxide Levels Enhances Plantlet Growth In Vitro
Authors: Tisserat Brent , Herman Christopher , Silman Robert , Bothast Rodney J.
Published: December 2018

A continuous CO2 flow system was used to study the growth of carrot (Daucus carota L.), citrus (Citrus macrophylla L.), kale (Brassica oleracea L.), lettuce (Lactuca sativa L.), radish (Raphanus sativus L.), and tomato (Lycopersicum esculentum L.) cultures in vitro under photoautotrophic, photomixotrophic, and heterotrophic conditions. Lettuce plantlets were grown on Murashige and Skoog medium with 0%, 0.3%, 1%, and 3% sucrose within flow chambers containing 350, 750, 1500, 3000, 10,000, 30,000, and 50,000 μL·L−1 CO2. Increasing the levels of CO2, especially at the ultra-high levels (i.e., ≥3,000 μL·L−1 CO2), increased fresh weight, shoot length, leaf number, leaf length, leaf width, root number, and root length for plantlets grown regardless of sucrose levels tested compared to plantlets grown at normal atmospheric CO2 levels, i.e., 350 μL·L-1. For example, fresh weights of lettuce plantlets grown on medium containing 0% or 3% sucrose increased 11- and 13-fold, respectively, when supplemented with 30,000 μL·L-1 CO2 compared to growth of lettuce plantlets grown on the same media without CO2 enrichment. Similar fold increases in growth responses were obtained with carrot, citrus, kale, radish, and tomato plantlets grown in atmospheres enriched with high CO2 levels, elevated from 3000 to 30,000 μL·L-1. Optimum CO2 concentration varied among species, suggesting a species-related response. Varying the rate of CO2 application between 250, 500, 1500, or 2000 mL·min-1 did not effect the rate of growth of lettuce plantlets. The passive diffusion continuous flow-through system presented in this paper is inexpensive, easily constructed, and allows for testing ultra-high CO2 levels on plant culture growth in vitro.
Effect of Natural Organic Nitrogen Fertilizers on Hybrid Bermudagrass Growth
Authors: Elliott M.L. , Prevatte M.
Published: December 2018

Eco, Milorganite, Ringer, and Sustane natural organic fertilizers, alone or combined with the synthetic organic fertilizer isobutylidene diurea (IBDU), were compared with IBDU alone for their effect on a `Tifdwarf' hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] golf course putting green. Over the 2-year study period, no consistent differences were observed among the fertilizer treatments on the turfgrass growth parameters of quality, clipping weights, or root weights.
Profile of an Active Master Gardener Chapter
Authors: Finch Calvin R.
Published: December 2018

The Bexar County (Texas) Master Gardeners (BCMGs) performed >33,000 hours of volunteer service in 1995 and again in 1996. In 1996 they raised $218,094 and spent $260,112 to operate ≈100 projects. MGs in partnership with the extension service can address priority issues within a community. They can provide the volunteer time, horticulture knowledge, and other skills such as problem solving and organizing abilities that attract partners, funds, and media coverage. Candidates for MG service in Bexar County heard about the BCMGs primarily from newspapers and word of mouth. MGs who stay active do so for the same reasons that they seek MG status: they want access to good horticultural information, they want to use their knowledge time on meaningful, fun projects, and they want to perform service with other gardeners.
Weed Management Effects on Insects and Diseases of Cabbage and Snapbean
Authors: Bottenberg Harry , Masiunas John , Eastman Catherine , Eastburn Darin
Published: December 2018

Field studies were conducted to determine insect and plant pathogen management effects on weed competitiveness and crop yield and to evaluate weed management impacts on insect pests, diseases, and crop yield. At similar densities, redroot pigweed (Amaranthus retroflexus L.) reduced snapbean (Phaseolus vulgaris L.) and cabbage (Brassica oleracea L. var capitata) yield more than that of common purslane (Portulaca oleracea L.), a low growing weed. In 1995, diamondback moth [Plutella xylostella (L.)] was greater on cabbage growing in plots with purslane than in plots of cabbage growing without weeds. Imported cabbageworm [Pieris rapae (L.)] was greater on cabbage growing in plots with either purslane or pigweed than when growing alone. However, the amount of feeding damage to cabbage was similar across treatments. Disease incidence was low, but fungicide treatments made redroot pigweed more competitive with snapbean, reducing yield in 1995.
Evaluating Rhizon Soil Solution Samplers as a Method for Extracting Nutrient Solution and Analyzing Media for Container-grown Crops
Authors: Argo William R. , Weesies Brian J. , Bergman Erica M. , Marshal Michelle , Biernbaum John A.
Published: December 2018

The rhizon soil solution sampler (RSSS) currently is being used for in situ extraction of the soil solution for nutrient analysis of mineral soils used to produce field-grown crops. In this study, laboratory and greenhouse experiments were conducted to test the effectiveness of the RSSS for in situ solution extraction from soilless container root media and to compare an RSSS extraction method for measuring root-medium pH, electrical conductivity (EC), and NO3-N and K concentrations with that measured with the saturated media extract (SME) method. A near 1:1 correlation was found between the pH, EC, and NO3-N and K concentrations measured in the extracted solution of the RSSS and SME method in media without plants and in media from ten species grown using three water-soluble fertilizer concentrations applied by subirrigation. More testing is needed with the RSSS, perhaps using composite samples form several pots for analysis. The RSSS shows promise for nutrient extraction in container-grown crops because it is fast, nondestructive, simple, economical, and has minimal effect on the nutritional status of the medium in the pot.