bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic Profile of Atlanta Landscape Maintenance and Lawn Care Firms
Authors: Florkowski Wojciech J. , Robacker Carol D. , Latimer Joyce G. , Braman S. Kristine
Published: December 2018

A survey indicated that the landscape maintenance and lawn care industry of the Atlanta metro area was localized in densely populated counties with a high concentration of commercial activity and residential housing. A relatively young age and limited size of most of the firms suggested a lack of barriers to entering the industry, which was supported by gross sales and equipment owned by surveyed companies. Most firms generated no more than $100,000 in sales in 1993 and owned equipment valued at less than $25,000. Most residential accounts were under 10 acres.
Comparison of Cucumbers Grown in Rockwool or Perlite at Two Leaching Fractions
Authors: Schon M.K. , Compton M. Peggy
Published: December 2018

Cucumbers (Cucumis sativus L. `Vetomil') were grown in rockwool or perlite to evaluate these media for efficient hydroponic cucumber production under Florida greenhouse conditions. Plants were grown using a double-stem training method, and the frequency of irrigations was controlled by a weighing lysimeter for each treatment. In Expt. 1, plants were grown in rockwool with 29% or 17% leaching fraction (LF) and in perlite with a 17% LF. Nitrogen, P, and K concentrations in the complete nutrient solution were 175, 50, and 180 mg·L−1, respectively. In Expt. 2, N, P, and K concentrations were increased to 225, 60, and 225 mg·L−1, respectively. Other nutrient concentrations and LFs remained as in Expt. 1. In Expt. 1, yields (fruit count and total fruit mass) were higher from plants grown in rockwool at 29% LF than from plants grown in rockwool or perlite at 17% LF. However, in Expt. 2, when nutrient concentrations were higher, total fruit mass was greater from plants grown at the lower LF, although there was no difference in fruit number. In both experiments, cucumber yield did not differ when grown at the same LF in either rockwool or perlite. Electrical conductivity (EC) and pH of the nutrient solution from the growing bags were not affected when LFs were decreased. In Expt. 1, the pH and EC ranged from 6.1 to 7.0 and from 0.9 to 1.6 mS·cm−1, respectively, across all treatments. In Expt. 2, pH and EC ranged from 5.3 to 6.9 and from 0.6 to 2.5 mS·cm−1, respectively, across all treatments.
Respiratory Rate and Vital Heat of Some Specialty Vegetables at Various Storage Temperatures
Authors: Peiris K.H.S. , Mallon J.L. , Kays S.J.
Published: December 2018

Respiratory rate was measured and vital heat calculated for 18 specialty vegetables {arugula or roquette [Eruca sativa Miller], banana flower bud [Musa ×paradisiaca L. var. paradisiaca], bitter gourd [Momordica charantia L.], cassava [Manihot esculanta Crantz], chayote [Sechium edule (Jacq.) Swartz], Chinese chive [Allium tuberosum Rottler ex Sprengel], Chinese water chestnut [Eleocharis dulcis (Burm. f.) Trin. ex Henschel], drumstick [Moringa oleifera Lam.], giant or elephant garlic [Allium scorodoprasm L.], guar [Cyamopsis tetragonoloba (L.) Taub.], hyacinth bean [Lablab purpurus (L.) Sweet.], Jerusalem artichoke [Helianthus tuberosus L.], jicama [Pachyrhizus erosus (L.) Urban], methi [Trigonella foenum-graecum L.], salsify [Tragopogon porrifolius L.], tindora [Coccinia grandis (L.) Voigt], tomatillo [Physalis ixocarpa Brot. ex Hornem.], and tumeric [Curcuma longa L.]} at 0, 5, 10, and 20 °C. Respiration rates increased more or less exponentially with increasing storage temperature in all the vegetables tested, CO2 varying from 28 to 302 mg·kg−1·h−1 at 20 °C for tumeric and drumstick, respectively. At 0 °C, the same products had the lowest and highest respiration rates of the products measured (i.e., CO2 at 4.5 and 28 mg·kg-1·h−1, respectively). Among the vegetables tested, above-ground plant parts such as leaves, fruit, and flowers generally had higher respiration rates than subterrancan storage organs such as roots, corms, and tubers. Vital heat produced ranged from 49 J·kg-1·h-1 for tumeric at 0 °C to 3272 J·kg-1·h-1 for drumstick at 20 °C.
Preliminary Evaluation of the Effects of Fluridone in Irrigation Water on Container-grown Azaleas
Authors: Kay Stratford H. , Monks David W. , Leidy Ross B.
Published: December 2018

In 1992, we initiated a study to determine the effects of fluridone in irrigation water applied to container-grown azaleas. Azaleas (Rhododendron indicum L. `George Tabor') were grown in containers with a 3 pine bark: 1 sand mixture and were irrigated daily for 5 weeks (except weekends) with solutions containing fluridone concentrations ≤2000 g·L−1. The threshold for appearance of visible injury symptoms (bleaching of new growth) was 250 g·L−1 at 5 and 12 weeks after treatment initiation. Visible symptoms did not appear until at least 35 days after treatments began. No statistically significant injury occurred to azaleas treated with solutions containing fluridone concentrations <250 g·L−1. This treatment rate was well above the maximum fluridone concentration (<90 g·L-1) normally occurring in ponds immediately following fluridone application. It appears unlikely that even long-term irrigation of `George Tabor' azaleas from fluridone-treated ponds would cause any significant injury.
Effect of Bottom Heat, IBA Dipping Duration, and Wounding on Rooting of Stem Cuttings of Milicia excelsa
Authors: Lin Yiqun , Wagner Michael R. , Cobbinah Joseph R.
Published: December 2018

The effect of bottom heat, wounding, and duration of stem basal IBA dip on macropropagation of Milicia excelsa was investigated. Bottom heat enhanced root dry mass and accelerated root initiation. Percentage rooting and root dry mass were not affected by wounding and duration of stem basal treatment. However, wounding interacted with bottom heat to affect dry mass (P < 0.05). Root biomass was 60% higher from wounded cuttings than from nonwounded cuttings under the nonheated condition. Chemical names used: 1H-indole-3-butyric acid (IBA).
Interseeding Legumes into Chile: Legume Benefits to a Following Crop of Forage Sorghum
Authors: Guldan Steven J. , Martin Charles A. , Lindemann William C. , Cueto-Wong Jose , Steiner Robert L.
Published: December 2018

Hairy vetch (Vicia villosa Roth.), barrel medic (Medicago truncatula Gaerth.), and black lentil (Lens culinaris Medik.) were interseeded into `New Mexico 6-4' chile pepper (Capsicum annuum L.) when plants were 8 to 12 inches tall or 12 to 16 inches tall in 1993 and 1994. Hairy vetch overwintered well both years, whereas barrel medic and black lentil did not. Spring aboveground dry mass yields of hairy vetch averaged 2.11 and 2.57 tons per acre in 1994 and 1995, respectively, while N accumulation averaged 138 and 145 pounds per acre in 1994 and 1995, respectively. Forage sorghum [Sorghum bicolor (L.) Moench] dry mass yield and N accumulation were significantly higher following hairy vetch than following the other legumes or no-legume control. There was no significant difference between forage sorghum yields following barrel medic, black lentil, or the no-legume control. Fertilizer replacement values (FRV) for the legumes were calculated from regression equations for forage sorghum dry mass yield as a function of N fertilizer rate. FRV for hairy vetch were at least 7-times higher than for either barrel medic or black lentil. Hairy vetch interseeded into chile pepper and managed as a winter annual can significantly increase the yield of a following crop compared to a nonfertilized control.
Survey of Pythium and Phytophthora spp. in Irrigation Water Used by Colorado Commercial Greenhouses
Authors: Pottorff Laura Pickett , Panter Karen L.
Published: December 2018

The purpose of this study was to determine if irrigation water is a source of Pythium and Phytophthora spp. introduction into Colorado greenhouses. Nine greenhouses took part in the study; three each used municipal, well, or surface water as their irrigation supply. Water samples were collected from each greenhouse three times during Summer 1993. Samples were filtered, filter pads were incubated on selective media, and isolated pathogens were used to inoculate susceptible Cucumis sativus L. and Lupinus polyphyllus Findl. indicator plants. Pythium rostratum Butler and P. dissotocum Drechsler were isolated from surface water supplies. No Phytophthora was found in any water source. No differences were found in stem length or leaf number on inoculated versus control cucumbers or lupines. It was determined that both species of Pythium recovered are weak pathogens. Apparently, pathogenic Pythium and Phytophthora spp. are introduced into greenhouses in three counties in Colorado via means other than water supply.
A New, Inexpensive Scanning Reflectometer and its Potential Use for Fruit Color Measurement
Authors: Reeves Stuart G. , Nock Jacqueline F. , Ludford Pamela M. , Hillman Lydia L. , Wickham Linda , Durst Richard A.
Published: December 2018

The use of a new, inexpensive scanning reflectometer, the Colortron, as a field and laboratory colorimeter is investigated. The results obtained from a series of color swatches and from a variety of fruit samples are compared with those obtained from other commercially available, but more expensive, colorimeters (Hunter and Minolta). The Colortron is shown to be very good for gathering and analyzing data. The results of all three instruments were extremely close when measuring color swatches, but the Colortron gave aberrant results with certain fruit having translucent skin and flesh. Despite this caveat, it still has considerable potential for the measurement of fruit color in the field and laboratory.
Impact of Adjuvants on Pecan Foliage
Authors: Wood Bruce W.
Published: December 2018

Of 18 commonly used adjuvants evaluated on pecan [Carya illinoinensis (Wangenh) K. Koch], a few exhibited potential for substantially suppressing net photosynthesis (A) and the conductance of foliage to water vapor (gsw) when used within their recommended concentration range; however, most provided no evidence of adversely influencing A or gsw. Suppression of gas exchange by certain adjuvants persisted at least 14 days after a single application. The recently developed organosilicone-based surfactants generally exhibited the greatest potential for suppression. These data indicate that orchard managers should consider the potential adverse influence of certain adjuvants when developing orchard management strategies.
Some Misconceptions About Fruit and Vegetables in Human Nutrition
Authors: Magee J.B.
Published: December 2018

The origins, demise and current status of some common misconceptions about the role of fruit and vegetables in human nutrition are discussed. Most, but not all, of the misconceptions were held by the public. The early widespread belief that tomatoes were poisonous was gradually overcome, and today the tomato is one of the most versatile and widely used foods in the diet. Recent reports suggest that consumption of tomatoes and tomato products has the potential to reduce the risk of certain cancers. Our current awareness of the potential of spinach in nutrition and health evolved from an early misconception that its only important nutritive value was as a source of iron. The connection between foods from the nightshade family and arthritis and the connection of cherries and gout relief are discussed briefly. The misconception that a wide variety of fruit and vegetables was not needed in the human diet was rejected long ago. Today fruit and vegetables are considered essential for their intrinsic nutritive value and for their potential health functionality because of the phytochemicals they contain.
Effect of Postharvest Handling and Storage on Apple Nutritional Status Using Antioxidants as a Model
Authors: Curry Eric A.
Published: December 2018

With the development of improved postharvest technology, the shelf life of fruit and vegetables has increased dramatically in many parts of the world. Presently, dietary recommendations for these commodities are based on the bioavailability of essential nutrients at the time of optimum harvest. Few people, however, are fortunate enough to have available freshly harvested produce all year and, therefore, must consume fruit and vegetables that have been stored under the best conditions available. The question, then, is whether nutritional quality changes with storage method and length. Little is known concerning the effects of storage on nutrient content or bioavailability. Furthermore, if levels of these antioxidants do indeed change, perhaps dietary recommendations should reflect this as well. The data in this study indicate that there are significant changes in the levels of natural antioxidants in two apple cultivars at harvest and after an extended period in cold storage.
Oxamyl Is an Effective Apple Fruit Thinner when Used Alone or when Combined with Other Thinners
Authors: Marini Richard
Published: December 2018

In five experiments with `Redchief Delicious' and one with `Braeburn', oxamyl (Vydate 2L) was used alone or combined with other chemicals to thin apples. The thinning response to oxamyl depended on dose. In most cases, oxamyl at 600 mg·L−1 and carbaryl at 900 mg·L−1 thinned trees similarly, but the combination of oxamyl plus carbaryl was no more effective than either chemical alone. The combination of oxamyl plus NAA (2.5 to 5 mL·L−1) was slightly more effective than either material alone. The thinning response to oxamyl and carbaryl was related to the concentration of superior oil added to the spray solution; for both chemicals, adding oil at 5 mg·L−1 or Tween 20 at 1.25 mL·L−1 gave equivalent thinning. Apples on trees sprayed with oxamyl plus oil had a dull finish. Adding Tween 20 at 1.25 mL·L−1 improved the thinning activity of carbaryl (Sevin XLR-Plus) more than oxamyl. Similar thinning occurred whether oxamyl was applied when fruit diameter averaged 4 or 10 mm. On `Braeburn' oxamyl, carbaryl, Accel, and NAA were mild thinners, but all combinations of oxamyl or carbaryl plus Accel or NAA overthinned the trees without improving fruit size. In general, oxamyl at 600 mg·L−1 (2 pints of vydate 2L/100 gal.) and carbaryl thin apple trees similarly, and the efficacy of both chemicals is improved by adding a surfactant.
Day-long Alterations of the Photomorphogenic Light Environment Affect Young Watermelon Plant Growth: Implications for Use with Rowcovers
Authors: Decoteau Dennis R. , Graham Heather A. Hatt
Published: December 2018

The sensitivity of watermelon [Citrullus lanatus (Thumb.) Matsum & Naki `Sugar Baby'] plant growth to day-long alterations in light quality was determined by exposing plants to light transmitted through broad band wavelength selective filters. Of the three acetate filters analyzed (nos. 19, 27, and 74), filter no. 74 transmitted the least amount of photosynthetic photon flux (PPF) (400 to 700 nm), the smallest red light: far-red light ratio (R:FR) (645:735 nm), and the greatest amount of blue light (400 to 500 nm) radiation from metal halide lamps. Plants grown under filter no. 74 were taller, had elongated petioles, and had a greater amount of petiole and stem biomass than plants grown under the other filters. Spectral transmission properties of commercially available rowcover materials were evaluated for variation of PPF, R:FR, and blue light. Clear polyethylene rowcovers were completely permeable to all measured (330 to 850 nm) wavelengths of radiation from metal halide lamps. White polyethylene rowcovers were the least permeable of the rowcover materials to wavelengths of radiation with decreases in the PPF, R:FR, and blue light. Spunbonded polyester materials slightly reduced PPF, R:FR, and blue light. Plants grown under white polyethylene and spunbonded materials grew taller (longer stems) than plants grown under the clear polyethylene rowcover. Petiole lengths were generally longer for plants grown under white polyethylene. Our results suggests that alterations in the R:FR and blue light due to selected wavelength transmission through commercially available rowcover material alter early watermelon growth.
Research Tools for Evaluating the Effects of a Vocational Horticulture Program on the Self-development of Female Inmates
Authors: Migura Melanie M. , Zajicek J.M.
Published: December 2018

Quantitative evaluation of horticulture vocational-therapy programs is becoming more and more critical as professionals in the area of people-plant interactions try to document the value of their programs. Evaluation tools to assess self-development of individuals studying such factors as self-esteem, life satisfaction, and locus of control have long been used in the social science disciplines. Many of these tools, either in their original forms or with some adaptations, can be successfully used to measure changes in self-development of individuals participating in horticulture programs.
Interactive Television Delivers Master Gardener Training Effectively
Authors: Stack Lois Berg
Published: December 2018

Five of the ten training sessions for Maine Master Gardeners (MGs) were taught using interactive television (ITV) in 1993. Trainees at one location participated in the sessions live; trainees at seven locations participated in the sessions from distant locations but in real time; and trainees at two locations viewed videotapes of the ITV sessions at later dates. Trainees (n = 215) were quizzed weekly to assess their level of learning and surveyed about their learning experience 6 months after completing their training. ITV distance learners' quiz scores and hours of volunteerism were equal to those of local learners. More than 90% of all respondents would enroll in a MG program again if it were conducted and taught locally, while 83.9% would enroll in a program taught half locally and half using ITV.
Potential Use of Wildflower Species for Landfill Restoration in Southwestern Virginia
Authors: Sabre M. , Cairns John , Holl Karen D. , Lyons Robert E.
Published: December 2018

Landfills are subject to public scrutiny because of potential environmental hazards, low aesthetic value, and rising costs of regulations governing landfill operation. In southwestern Virginia, landfill operators commonly seed landfills with nonnative perennial forbs and grasses. Our goal was to determine if wildflowers were a feasible alternative to the standard revegetation mixture. A standard landfill revegetation mixture and a wildflower mixture were sown at a landfill in Spring 1993 and were evaluated after one growing season. The number of species established in the wildflower mixture subplots was greater than in the standard mixture subplots, whereas cover of the two mixtures did not differ significantly. Rudbeckia hirta, Coreopsis lanceolata, Coreopsis tinctoria, and Hesperis matronalis thrived. Lespedeza cuneata was a confounding factor in determining cover estimates. Results of our study suggest that several native and naturalized species have potential for landfill restoration.
Rowcover-removal Timing Affects Yield of Tomatoes Planted on Fall-prepared Beds
Authors: Reiners Stephen , Nitzsche Peter J. , Tietjen William H.
Published: December 2018

Spring-planted `Pilgrim' tomatoes (Lycopersicon esculentum) were grown under slitted clear polyethylene rowcovers on beds prepared in the fall with black plastic mulch and trickle irrigation. Fall beds allowed for earlier planting and a corresponding earlier harvest. Plastic mulch and trickle irrigation remained intact during the winter. There was no significant advantage to leaving covers on past the time of the traditional planting date for the area. It was estimated that the additional cost for this system would be about $1000 per acre. The profitability of this system will be determined by the price growers receive for their earliest fruit. An early season price of $0.60/1b is the approximate break-even figure. Higher early season prices will lead to much greater profits. For heatsensitive crops like tomatoes, using rowcovers on fall beds may effectively maximize early yield and profitability.
Critical Comparison of an Accelerometer and a Laser Doppler Vibrometer for Measuring Fruit Firmness
Authors: Muramatsu Noboru , Tanaka Keiichi , Asakura Toshikazu , Ishikawa-Takano Yuko , Sakurai Naoki , Wada Naoki , Yamamoto Ryoichi , Nevins Donald J.
Published: December 2018

To examine the feasibility of using a laser Doppler vibrometer (LDV) for fruit quality evaluation, measurements of firmness derived by this method were compared with those acquired using a contact accelerometer. Apples (Malus pumila Miller var. Domestica Schneider `Fuji'), kiwifruit [Actinidia deliciosa (A. Chev.) Liang et Ferguson, `Hayward'], Japanese pear [Pyrus pyrifolia (Burm. f.) Nakai var. Rehd. `Nijusseiki'], and Hassaku (Citrus hassaku Hort. ex Tanaka) were used. Fruit were subjected to sine waves at frequencies from 5 to 2000 Hz at the basal surface, and the vibrations resulting from these transmissions were precisely montitored at the upper surface with a LDV monitor. Measurements on all of the tested single fruit exhibited a distinct phase shift in the applied sine wave and in the responance frequency, dependent on frequency used. These shifts were also detected by an accelerometer, but in this case the range of frequency was restricted to an upper limit of 400 Hz for kiwifruit and 800 Hz for Japanese pear and Hassaku. Efforts to extend the range using a greater vibrational mass with the accelerometer resulted in anomalous tissue behavior, most likely due to excesive compression when the weight exceeded 1 g. Hence firmness measurements of fruit depended on the phase shift and resonance frequency, which were achieved with more precision by LDV than accelerometer. Since LDV measurements of fruit firmness were made without directly contacting the fruit surface, it could be potentially used for on-line quality evaluation and fruit sorting.
Fertilizer Management by Landscape Maintenance and Lawn Care Firms in Atlanta
Authors: Beverly Reuben B. , Florkowski Wojciech , Ruter John M.
Published: December 2018

In response to a mail survey of the landscape maintenance and lawn care (LM-LC) industry in metropolitan Atlanta, we learned that 76% of respondents fertilized lawns and turf and 68% fertilized ornamental beds. Less than one-fourth of those who provided fertilization services offered an organic fertility option; for those who reported an organic option, an average of 25% of their residential customers used such a service. Complete fertilizers (N-P2O5-K2O), ammonium nitrate, urea, and N solutions were the products applied by most respondents. Average amounts of N per application were ≈1.5 lb/1000 ft2 on lawns and 1.1 lb/1000 ft2 on ornamentals. Of firms that provide fertilization services, 88% use a predetermined application schedule, whereas 88% use visual observation and 69% use soil testing to guide fertilizer management. Only 5% reported using tissue analysis as a fertilizer management strategy. Nitrogen fertilizers were applied most frequently in the spring, with nearly equal amounts applied in summer and fall. Phosphorus was applied most commonly in the fall or spring. Relatively few firms reported applying significant amounts of either N or P in winter. Most respondents indicated that they received adequate information about fertilizers, but few received information about organic fertilization. Commercial sales representatives and trade magazines were cited most often as sources of information; university specialists were the least-cited formal source of information concerning fertilization. We have suggested some research and educational issues to be addressed based on these results.
Basics of Frost and Freeze Protection for Horticultural Crops
Authors: Perry Katharine B.
Published: December 2018

Basic meteorology as it applies to frost-freeze events and a discussion of the methods of frost protection are included in this article. The presentation of basic meteorology includes descriptions of heat transfer, energy exchange, inversion, frost, freeze, microclimate, air versus crop temperature, and forecasts and warnings in the context of how each of these in involved in frost-freeze events. The second part of the paper describes the major methods of frost protection for commercial crops. The methods included are site selection, irrigation (overhead, undercanopy, man-made fog, flooding), wind machines, heaters, covers, and sprayable materials.
Yield and Virus Resistance of Summer Squash Cultivars and Breeding Lines in North Carolina
Authors: Schultheis Jonathan R. , Walters S. Alan
Published: December 2018

Yellow and zucchini squash (Cucurbita pepo L.) cultigens (breeding lines and cultivars) were evaluated over a 2-year (1995 and 1996) period in North Carolina. Yellow squash cultigens that performed well (based on total marketable yields) were `Destiny III', `Freedom III', `Multipik', XPHT 1815, and `Liberator III' in Fall 1995 and HMX 4716, `Superpik', PSX 391, `Monet', `Dixie', XPH 1780, and `Picasso' in Spring 1996. Some of the yellow squash cultigens evaluated had superior viral resistance: XPHT 1815, XPHT 1817, `Freedom III', `Destiny III', `Freedom II', TW 941121, `Prelude II', and `Liberator III' in Fall 1995 and XPHT 1815, `Liberator III', `Prelude II', and `Destiny III' in Fall 1996; all these cultigens were transgenic. The yellow squash cultigens that performed well (based on total marketable yields) in the Fall 1995 test had transgenic virus resistance (`Destiny III', `Freedom III', XPHT 1815, and `Liberator III') or had the Py gene present in its genetic background (`Multipik'). Based on total marketable yields, the best zucchini cultigens were XPHT 1800, `Tigress', XPHT 1814, `Dividend' (ZS 19), `Elite', and `Noblesse' in Fall 1995; and `Leonardo', `Tigress', `Hurricane', `Elite', and `Noblesse' in Spring 1996. The zucchini cultigens with virus resistance were TW 940966, XPHT 1814, and XPHT 1800 in Fall 1995 and XPHT 1800, XPHT 1776, XPHT 1777, XPHT 1814, and XPHT 1784 in Fall 1996. Even though TW 940966 had a high level of resistance in the Fall 1995 test, it was not as high yielding as some of the more susceptible lines. Viruses detected in the field were papaya ringspot virus (PRSV) and watermelon mosaic virus (WMV) for Fall 1995; while PRSV, zucchini yellow mosaic virus (ZYMV), and WMV were detected for Fall 1996. Summer squash cultigens transgenic for WMV and ZYMV have potential to improve yield, especially during the fall when viruses are more prevalent. Most transgenic cultigens do not possess resistance to PRSV, except XPHT 1815 and XPHT 1817. Papaya ringspot virus was present in the squash tests during the fall of both years. Thus, PRSV resistance must be transferred to the transgenic cultigens before summer squash can be grown during the fall season without the risk of yield loss due to viruses.
Abscisic Acid as a Potential Deciduous Fruit Tree Nursery Stock Defoliant
Authors: Larsen Fenton E. , Higgins Stewart S.
Published: December 2018

Abscisic acid (ABA) was tested as a defoliant for nursery trees of `Bartlett' pear (Pyrus communis L.) and the apple (Malus×domestica Borkh.) cultivars Imperial Gala, Gibson Golden Delicious, Scarlet Spur Delicious, Law Red Rome, Granny Smith, Braeburn, and Red Fuji. ABA was sprayed once or twice, with 1 intervening week, at 500, 1000, or 2000 ppm. Percentage defoliation was assessed at 1-week intervals for 4 weeks. For all cultivars, two applications of 2000 ppm ABA ranked among the most effective treatments for rapid defoliation; this treatment led to at least 95% defoliation for all cultivars. For many cultivars, however, other treatments caused similar defoliation percentages by digging time. All tested cultivars were effectively defoliated (>80%) by two 1000-ppm applications ABA or one 2000-ppm application. One or two 500-ppm applications effectively defoliated `Bartlett', `Gibson Golden Delicious', and `Law Red Rome'. Nursery managers, therefore, need to consider a range of ABA concentrations and alternative application protocols to obtain optimum benefit from ABA. Although ABA shows promise as a defoliant, it lacks government approval for commercial use.
Using Composted Wastes on Florida Vegetable Crops
Authors: Ozores-Hampton Monica , Obreza Thomas A. , Hochmuth George
Published: December 2018

Large volumes of compost produced from waste materials like yard trimmings, household trash (municipal solid waste), or biosolids (wastewater sludge) will likely become available for use by the Florida vegetable industry in the future. Using compost to produce vegetables has the potential to increase water and fertilizer conservation and reduce leaching from inorganic fertilizers in Florida's sandy soils. Compost quality for vegetable production systems should be based on soluble salts, phytotoxic compounds, C:N ratio, plant nutrients, trace metals, weed seeds, odor, moisture, pH, water-holding capacity, bulk density, cation exchange capacity, and particle size. In Florida, immature compost contained phytotoxic compounds that were harmful to crop germination and growth. Amending soil with mature composted waste materials has been reported to increase the growth and yields of vegetable crops grown in Florida. However, a beneficial response does not always occur, and the magnitude of the response is often not predictable.
Factors Influencing Pesticide Use and Integrated Pest Management Implementation in Urban Landscapes: A Case Study in Atlanta
Authors: Braman S.K. , Latimer J.G. , Robacker C.D.
Published: December 2018

Questionnaires on pesticide use and other aspects of integrated pest management (IPM) were mailed to 1678 lawn care and landscape maintenance firms in the 20 county metropolitan Atlanta area. The survey return rate adjusted for nonapplicable addresses and undeliverable mailings was 25.4%, yielding a total of 350 usable surveys. Responding lawn care and landscape maintenance professionals purchased a total active ingredient of 250,527 lb (93,447 kg) of herbicide, 35,416 lb (13,210 kg) of insecticide and 10,367 lb (3,867 kg) of fungicide during 1993. Most insecticides and fungicides were applied during June, July, and August. About one-third of herbicides were applied during March to May, one-third during June to August, and one-third during September to February. Key pests and plants were identified by survey respondents. Opportunities and impediments to implementation of IPM in the landscape as reported by respondents are discussed.
Selecting and Propagating Rootstocks to Produce Apricots
Authors: Southwick Stephen M. , Weis Kitren G.
Published: December 2018

Selection and propagation of rootstocks for apricot (Prunus armeniaca L.) varies worldwide in response to local climate, soils, and cultivars. In this paper we review published research focused on these local selective practices. Additionally, we review the current development of apricot rootstocks and suggest new research avenues to satisfy the needs of commercial apricot growers. Rootstocks are identified by their responses to biotic and environmental stresses, with specific adaptive characteristics that enable establishment and production under unique zonal ecologies. Desirable characteristics include scion compatibility, adaptation for heavy or wet soils, pest and disease resistance, ease of propagation, control of vegetative vigor, effects on dormant season physiology of the scion, precocity, fruit quality, and productivity. Interstocks that can overcome incompatible rootstock-scion combinations are covered. As worldwide consumer demand for apricots increases with improved apricot cultivars, rootstock selections and propagation must be developed for niche fruit with specific characteristics, intensive production systems, mechanized harvest, and marginal site selection.
Seeding Uniformity of Precision Seeders
Authors: Bracy Regina P. , Parish Richard L.
Published: December 2018

Stanhay, Carraro, and Gaspardo precision vegetable seeders were evaluated for seeding uniformity with seeds of five vegetable crops—cabbage (Brassica oleracea L. Capitata group), carrot (Daucus carota L.), cucumber (Cucumis sativus L.), onion (Allium cepa L. Cepa group), and spinach (Spinacia oleracea L.). Five measurements [mean, percentage of misses, percentage of multiples, quality of feed, and precision (defined as the coefficient of variation after misses and multiples were discarded)] were used to evaluate seeder uniformity. Using all five measurements provided a more complete determination of the metering uniformity of the seeders than was possible in prior work when only mean and coefficient of variation were used. The belt seeder (Stanhay) was effective at singulating spherical seeds (cabbage) and nearly spherical seeds (onion)as the most precise vacuum seeder (Carraro). Seeding uniformity of all seeders with elongated (carrot and cucumber) or angular (spinach) seeds was inadequate for precision seeding.
The Game Show Challenge: Catalyst for Student Participation in Plant Propagation
Authors: Smith M.A.L. , Rogers R.B.
Published: December 2018

The game-show format, used recurrently in an undergraduate-level, introductory plant propagation course, fostered a friendly, competitive incentive for students to master facts and concepts critical to understanding processes in plant physiology. Because student teams, rather than individuals, served as the contestants in each game, and because game points were never translated into grade points, participants and observers learned from and enjoyed the exercises without anxiety. Propagation-specific clues and questions were prepared for “Wheel of Fortune,” “Win, Lose, or Draw,” and other games. These were followed up at the end of each semester with several play-off rounds of a plant propagation variant of “Jeopardy!”, which served as an excellent means of course synthesis and review of key concepts. The format allowed for liberal use of humor as an effective pedagogical tool and resulted in the hands-on contributions of former students in construction of new game quizzes and puzzles for subsequent semesters.
Micropropagation of Temperate Cymbidium via Rhizome Culture
Authors: Paek Kee Yoeup , Kozai Toyoki
Published: December 2018

We report the results of serial studies aimed at clarifying several factors affecting organogenesis in rhizome culture of temperate Cymbidium species and their hybrids. The growth patterns and regeneration ability of rhizomes derived from asymbiotic seed or shoot tip culture vary according to media composition, kinds and concentrations of plant growth regulators, culture conditions, and species and varieties. N6-benzyladenine was the best cytokinin for inducing shoot formation, for switching rhizome tissues into protocorm-like bodies, and for directly forming multiple shoots from branched rhizomes. Activated charcoal appeared to be necessary for producing healthy plantlets and for stimulating shoot growth at levels of 0.1% to 0.3% but concomitantly decreased rhizome growth. Sucrose at 5% was the most effective concentration for shoot induction from rhizomes. The above results support the conclusion that organogenic pathways between tropical, subtropical, and temperate Cymbidium species may be controlled by the genetic backgrounds of the species or cultivars.
Efficient, Collaborative, Inquiry-driven Electronic Information Systems
Authors: Gilman Edward F. , Green James L.
Published: December 2018

Electronic information systems provide efficient information management—development, updating, storage, retrieval, and delivery. No more stockpiling of printed, going-out-of-date information when specific, concise, up-to-date information can be obtained just in time from the Internet. Authoring for electronic media is different than authoring for the printed page. To use unique characteristics of electronic information systems, information is presented in chunks, small units of information that can combine text, video, or sound to present one concept or to answer one question. A chunk may be linked to other chunks to provide definitions and further elaboration of terms or ideas. A chunk may be linked to related chunks to provide comprehensive information inquiry-driven by and tailored to the inquirer's interests and understanding. A chunk may be linked to other chunks to provide definitions and further elaboration of terms or ideas. Collaboration is facilitated by the World Wide Web (Web). Shared development reduces redundant efforts and costs and results in better products than can be produced by autonomous efforts. Continual, shared development and updating keep the individual chunks and the linked chunks (URLs) up-to-date and dynamic. Educators can thread (link) selected web modules or chunks (URLs) together into dynamic study assignments or dynamic textbooks for courses of study. To obtain the best of both media, CD-ROM software can be designed to interact with a Web site. The ways that CD-ROM and online are interacting are varied and evolving. Graphics-rich databases such as color photographs of plants or pests and related text that do not require continual updating are well suited to CD-ROM. Web links from the CD-ROM to additional, dynamic information and updates at the Web site keep the CD-ROM live and current. ASHS members are uniquely qualified to generate continually updated, peer-reviewed horticultural information on the web for continuous access by the interested learner whose pathway on the web will be inquiry-driven.
Using HortBase in Education
Authors: Kjelgren Roger , Rupp Larry
Published: December 2018

Computer technology allows horticultural educators to convey information more flexibly and visually to a greater audience. However, accessing and making use of technological teaching tools is as much a hurdle as it is an opportunity. HortBase provides the framework for educators in horticulture to easily access and contribute to quality chunks of horticultural educational by computer. Engaging computer-based instruction such as HortBase in distance or on-campus teaching is a three-step process. First, before assembling the teaching material, the educator must decide on who the target audience is and what information to convey. Audiences on campus often have higher expectations of how they want to learn, being accustomed to face-to-face instruction and guidance, but may not have a clear idea of what they want to learn. Off-campus audiences may have lower expectations but generally are more focused on the information they want. Second, the educator then must decide on how much of the information to bring into digital form oneself and what to draw from elsewhere. Chunks of digitized information can be created by scanning existing images into the computer or created on computer with drawing programs. Once digitized, images can be manipulated to achieve a desired look. This is laborious, so much effort can be saved by taking created chunks from HortBase. Finally, choose a medium for dissemination. Course content can be presented with slide-show software that incorporates digitized slides, drawing, animations, and video footage with text. Lectures can then be output to videotape or broadcast via an analog network. Alternatively, the digitized information can be incorporated into interactive packages for CD-ROM or the World Wide Web.
Integrating the World Wide Web into Existing Extension and Educational Technology
Authors: Lineberger R. Daniel
Published: December 2018

Studies by academic, extension, and private foundation think tanks have reaffirmed the land-grant philosophy as an important component of American society in the twenty-first century. Successful land-grant systems will have more closely integrated educational, research, and extension programs characterized as more accessible, affordable, and accountable than current models. The World Wide Web (Web) will play a key role in this transformation. Web technology is evolving rapidly, necessitating continuous and rapid adaptation by information providers (Lineberger, 1996a, 1996b; Rhodus and Hoskins, 1996). The availability of low-cost, user-friendly Web access through home TVs promises to upset the existing paradigms of extension information delivery through county offices and undergraduate instruction exclusively in the campus classroom. Some land-grant professionals have adopted Web technology as a tool to deliver educational programs and coursework; however, most have not, citing as justification the very steep learning curve and time involved in formatting materials for electronic delivery. We have emphasized the need for lifelong learning to our clientele and students; we must heed our own advice. Faculty must develop the ability to integrate appropriate technology into their own programs, since it is clear that land-grant systems of the future will not provide them with the support personnel to do it for them.
ASHS Strategic Planning and HortBase
Authors: Albrecht Mary Lewnes
Published: December 2018

The ASHS Strategic Plan consists of four key result areas. Key Result Area One: Enhance Internal Services, identifies various aspects of communication with and enhancing services for the membership. Strategy Three calls for the development of an information highway through advanced communication technologies. Strategy Four seeks to enhance services for international members and Strategy Five and Six addresses increasing the involvement of graduate and undergraduate students and increasing the value of membership to diverse members. There are various other aspects of the Strategic Plan dealing with promoting horticulture and horticulture information dissemination that are affected by HortBase. How the development and implementation of HortBase will help ASHS reach these objectives is discussed.
Interplanted Small Grain Cover Crops in Pickling Cucumbers
Authors: Zandstra Bernard H. , Chase William R. , Masabni Joseph G.
Published: December 2018

Pickling cucumbers (Cucumis sativus L.) for machine harvest were interplanted with barley (Hordeum vulgare L.), oat (Avena sativa L.), rye (Secale cereale L.), sorghum-sudan (Sorghum vulgare L.), or wheat (Triticum aestivum L.). Cover crops 3 to 5 (7.6 to 12.7 cm) or 6 to 10 inches (15.2 to 25.4 cm) tall were killed with sethoxydim. Cover crops seeded at ≈12 seeds/ft2 (129 seeds/m2) provided protection from wind erosion and minimal crop competition. Additional nitrogen to obtain maximum yield was required when small grain cover crops were interplanted with cucumbers. Barley emerged rapidly, grew upright, and was killed easily with sethoxydim, making it ideal for interplanting. All cover crops caused some cucumber yield reduction under adverse growing conditions.
Evaluation of Zeolite-based Soilless Root Media for Potted Chrysanthemum Production
Authors: Carlino Janet L. , Williams Kimberly A. , Allen Earl R.
Published: December 2018

Chrysanthemum [Dendranthema ×grandiflorum (Ramat.) Kitamura] growth and nutrient leaching of three clinoptilolite-based root media—NZ, EZ1, and EZ2—were compared to the performance of control plants grown in Sunshine Mix #2 [3 peat : 1 perlite (v/v)]. The control received 210 mg·L−1 N from an 18N-4P-15K soluble fertilizer at each irrigation. NZ contained untreated zeolite and received the same soluble fertilizer as the control but leached lower concentrations of NH4-N, K, and PO4-P during most of the production cycle compared to the control. EZ1 was formulated to provide N, P, and K as fertilizer nutrients and produced plants similar to the control based on ratings, height, width, and dry mass, but not fresh mass, at harvest when the fertilizer rate was half of that applied to the control—105 mg·L-1N. EZ2 did not receive P or K from soluble fertilizer and produced plants similar to the control based on rating, height, and dry mass, but not width or fresh mass, with soluble fertilizer input reduced to N alone. Tissue N, P, and K concentrations of plants grown in EZ1 and EZ2 were lower than those of control plants. With further refinements, these zeolitebased products show promise for decreasing nutrient leaching during crop production and allowing for application of lower rates of soluble fertilizers.
Spring Freeze Damage to the 1996 Peach and Nectarine Crop in the Southeastern United States
Authors: Okie W.R. , Beckman T.G. , Reighard G.L. , Newall W.C. , Graham C.J. , Werner D.J. , Powell A.A , Krewer G.
Published: December 2018

This paper describes the climatic and cropping conditions in the major peach [Prunus persica (L.) Batsch] producing areas in the southeastern United States in 1996. The peach and nectarine crop was the smallest since 1955 due to a series of unusually cold temperatures in February, March, and April. Crop set was not strictly a function of late blooming. No variety produced a full crop across the region. Many reputedly hardy peaches cropped poorly. The only peach or nectarine varieties that produced substantial crops in multiple locations were `La Premiere', `Ruston Red', and `Contender'. Cropping ability of some breeding selections shows that peach frost tolerance may be improved further.
Responses of Field-grown Tomatoes to Nitrogen Sources
Authors: Guertal E.A. , Kemble J.M.
Published: December 2018

Although the effect of various N fertilizers on tomato yield and quality has been previously examined, much of this research was conducted in hydroponic or green-house studies. The objective of this research was to examine the effect of N fertilizer sources (ammonium nitrate (NH4NO3), potassium nitrate (KNO3), urea (CO(NH2)2), urea ammonium nitrate (UAN), and calcium nitrate (Ca(NO3)2) on tomato (Lycopersicon esculentum Mill.) growth, yield, and fruit quality. The 2-year experiment was conducted using black plastic mulch covered raised beds with drip fertigation. A total of 180 lb acre (202 Kg·ha−1) N was applied with each N source, with 25% applied preplant and premulch and remaining N applied as 10 weekly applications of 13.5 lb/acre (15.2 kg·ha−1). If an N source contained Ca or K, that amount was applied to all other N sources (preplant and fertigated) as potassium chloride (KCl) or calcium chloride (CaCl2). Collected data included plant height, leaf N concentration, and yield. Different N sources had varying and inconsistent effects on fruit yield and quality. Although plant height and stem diameter from UAN treatments were always smaller than those from other N sources, this effect did not extrapolate to decreased total marketable yield. Differences in N concentration of tomato leaf tissue were not consistent with N source and were not related to differences in tomato yield. There were few differences in yield and quality of nonmarketable fruit due to N source. In this one-site, 2-year study, it appears that any of the N sources studied would be suitable for tomato production, if price of N fertilizer materials are the same.
Reducing Solid Waste Streams Specific to Soilless Horticulture
Authors: Pieters J. , Van Assche B. , Buekens A.
Published: December 2018

The solid waste streams specific to soilless horticulture (substrate slabs, propagation cubes, and plastic films to cover the soil and to wrap the substrate slabs) were determined quantitatively and qualitatively, while methods to reduce these waste streams without yield loss were evaluated in a case study applied to the Flanders region of Belgium and based on an explorative inquiry among horticulturists. Rockwool used for substrate slabs and propagation cubes was found to be by far the most important waste stream. The use of long-lived, polyurethane (PUR) slabs could reduce the total slab waste stream by ≈90%. Moreover, if substrate blocks are used instead of slabs, this reduction could even increase to 95%. The introduction of new cultivation techniques could further reduce the required volume of substrate slabs. Rockwool propagation cubes could be successfully replaced with peat pots that can be composted after 1 year of use. The reuse of plastic films to cover the soil or to wrap the substrate slabs cannot be considered because of the danger of plant diseases. Due to the susceptibility of these films to contamination, they cannot yet be recycled on a large scale. The use of thinner films and the cultivation on profiled concrete floors were found to allow drastic reductions (of up to 80%) of the quantity of plastics used.