bluuebunny/crossref_metadata_2025 huggingface dataset:
Reducing the Pollution Potential of Pesticides and Fertilizers in the Environmental Horticulture Industry: II. Lawn Care and Landscape Management
Authors: Latimer Joyce G. , Beverly Reuben B. , Robacker Carol D. , Lindstrom Orville M. , Braman S. Kristine , Oetting Ronald D. , Olson Denise L. , Thomas Paul A. , Walker Jerry T. , Sparks Beverly , Ruter John M. , Florkowski Wojciech , Garber Melvin P. , Hudson William G.
Published: December 2018

Optimizing growing conditions and, thereby, plant growth reduces the susceptibility of plants to many disease and insect pest problems. Educating lawn or landscape management professionals and homeowners about plant health management reduces the need for chemical intervention. Pesticides combined with N and P fertilizers contribute to water pollution problems in urban areas; thus, it is important to manage the amount, timing, and placement of chemicals and fertilizers. To educate consumers applying pesticides and fertilizers in residential gardens, we must educate the sales representatives and others who interact most closely with consumers. Evidence suggests that knowledge about the effects of chemicals is limited and that warning labels are not read or are ignored. Integrated pest management (IPM) offers alternatives to conventional chemical treatments, but such methods are not used commonly because of their relatively high cost and their uncertain impact on pests. Pest detection methods and using pest-resistant plants in landscapes are simple and, in many cases, readily available approaches to reducing the dependence on chemical use. Research on effective, low-cost IPM methods is essential if chemical use in landscape management is to decrease. Current impediments to reducing the pollution potential of chemicals used in the landscape include the limited number of easily implemented, reliable, and cost-effective alternative pest control methods; underfunding of research on development of alternative pest control measures; limited knowledge of commercial operators, chemical and nursery sales representatives, landscape architects, and the general public concerning available alternatives; reluctance of the nursery industry to produce, and of the landscape architects to specify the use of, pest-resistant plant materials; lack of economic or regulatory incentive for professionals to implement alternatives; inadequate funding for education on the benefits of decreased chemical use; and the necessity of changing consumer definition of unacceptable plant damage. We need to teach homeowners and professionals how to manage irrigation to optimize plant growth; use sound IPM practices for reducing disease, weed, and insect problems; and minimize pollution hazards from fertilizers and pesticides.
Intergeneric Graft Compatibility within the Family Araliaceae
Authors: Leonhardt Kenneth W.
Published: December 2018

Novelty Araliaceae potted plants were created by a wide variety of interspecific and intergeneric graft combinations. Twenty-four species of 10 genera were tested, of which 20 species of eight genera resulted in 85 graft combinations that grew. Intergeneric graft combinations with Schefflera arboricola included eight species in five other genera. Intergeneric graft combinations with x Fatshedera lizei included 11 species in five other genera. Schefflera arboricola scions grew more vigorously on Nothopanax and Polyscias rootstocks than on Schefflera root-stocks. The highest intergeneric graft compatibility scores for each genera included combinations with Schefflera. Plant propagation instructors may find these results useful in designing grafting exercises.
Establishing Pecan Transplants
Authors: Wood Bruce W.
Published: December 2018

Pecan [Carya illinoinensis (Wangenh.) K. Koch] nursery transplants performed best on establishment in nonirrigated orchards when using large trees planted early in the dormant season. After 6 years, growth and survival of bare-root transplants were equal to that of containerized transplants when established during the dormant season. Reducing transplant trunk height by ≤75% at planting did not affect subsequent tree survival, although rate of height growth and tree vigor increased such that there was no difference between pruned and nonpruned trees after 3 years, except that pruned trees appeared to possess greater vigor. There also were no differences in growth or survival between augured and subsoil + augured planting sites within 6 years of transplanting, and there were no differences between root pruned (severe tap or lateral root pruning) and nonpruned trees.
Strain of Shiitake Mushroom [Lentinula edodes (Berk.) Pegler] and Wood Species Affect the Yield of Shiitake Mushrooms
Authors: Sabota Cathy
Published: December 2018

Logs of white and red oak (Quercus spp.), black cherry [Prunus serotina (Ehrh.)], sassafras (Sassafras albidum (Nutt.) Nees), and eastern sycamore [Platanus occidentalis (L.)] were inoculated with eight strains of shiitake mushroom in 12-mm holes drilled 25 mm deep and spaced 15 cm apart down the log and 5 cm apart around the log in a staggered pattern. Logs then were placed in quonset houses covered with 80% shadecloth in Mar. 1991. The environment within these shaded houses was not modified otherwise. Harvested mushrooms were counted and weighed and biological efficiency (BE) was determined. White and red oaks produced significantly higher yields of shiitake mushrooms over the lifetime of the log than the other types of wood. Only one strain, CW25, produced significantly lower yields than the best four strains. Interactions among strains and seasons of harvest and the species and seasons of harvest were significant. The most productive mushroom strains and tree species yielded more mushrooms later in the life of the logs than the least productive strains and tree species did earlier in the life of the logs. BE attained from strain × species interactions ranged from 0% (WW70, CW25, and WR85 on sycamore) to 8.8% (WW44 on red oak) in an outdoor noncontrolled environment. The gross per cord value (at wholesale price) of shiitake harvested from white oak was $2475.00. The cost of producing one cord of shiitake is about $6.44 per log in a small-scale operation. A net return of $1509.00 per cord is realistic and includes the cost of labor.
Temperature and Photoperiod Affect Grafted Cactus Scion Necrosis
Authors: Erwin John E.
Published: December 2018

The interaction among temperature, photoperiod, and irradiance on survival of Chamaecereus silvestrii (yellow sport) flat-grafted onto Hylocereus trigonus Haw. rootstock was studied in an effort to understand the basis for elevated scion necrosis during winter. Plants were placed in glasshouses maintained at 12, 16, 20, or 24 °C under either daylight (moles per day), 66% daylight or daylight + 100 μmol·s−1·m−2 irradiance levels. Plants were grown with an 8-hour (short day) or 8-hour + 4-hour night interruption (long day) photoperiod. Cactus scion necrosis increased under short days and a growing temperature of 12 °C and was nearly eliminated by long-day conditions and a growing temperature of 16 °C. Irradiance did not affect scion necrosis. Plant quality rating was highest when plants were grown under long-day conditions at 16 °C.
Assessing Vascularization Response of Three Tomato (Lycopersicon esculentum Mill.) Cultivars to Soil Type, Nutrient Stress, and Water Stress
Authors: Sanders Douglas C. , Cure Jennifer D. , Deyton Pamela M. , Gardner Randolph G.
Published: December 2018

Amount of vascular development (veininess) is an important quality factor for processing wholepack tomatoes. The influences of nutrient and soil moisture stress on the amount of vascular development in `Chico III', `Dorchester', and `Roma' tomato fruit were studied. Fruit subjected to nutrient stress showed the highest amount of veininess. Fruit exposed to moisture stress after initial fruit set did not differ from controls in amount of veininess. Amount of vascularization did not differ among cultivars. A method for quantifying veininess was developed and compared with a traditional subjective rating scale. There was a high correlation (r2 = 0.77) between the subjective rating and quantitative measurement of veininess.
Plant Water Status as an Index of Irrigation Need in Deciduous Fruit Trees
Authors: Shackel Kenneth A. , Ahmadi H. , Biasi W. , Buchner R. , Goldhamer D. , Gurusinghe S. , Hasey J. , Kester D. , Krueger B. , Lampinen B. , McGourty G. , Micke W. , Mitcham E. , Olson B. , Pelletrau K. , Philips H. , Ramos D. , Schwankl L. , Sibbett S. , Snyder R. , Southwick S. , Stevenson M. , Thorpe M. , Weinbaum S. , Yeager J.
Published: December 2018

To be useful for indicating plant water needs, any measure of plant stress should be closely related to some of the known short- and medium-term plant stress responses, such as stomatal closure and reduced rates of expansive growth. Midday stem water potential has proven to be a useful index of stress in a number of fruit tree species. Day-to-day fluctuations in stem water potential under well-irrigated conditions are well correlated with midday vapor-pressure deficit, and, hence, a nonstressed baseline can be predicted. Measuring stem water potential helped explain the results of a 3-year deficit irrigation study in mature prunes, which showed that deficit irrigation could have either positive or negative impacts on tree productivity, depending on soil conditions. Mild to moderate water stress was economically beneficial. In almond, stem water potential was closely related to overall tree growth as measured by increases in trunk cross-sectional area. In cherry, stem water potential was correlated with leaf stomatal conductance and rates of shoot growth, with shoot growth essentially stopping once stem water potential dropped to between −1.5 to −1.7 MPa. In pear, fruit size and other fruit quality attributes (soluble solids, color) were all closely associated with stem water potential. In many of these field studies, systematic tree-to-tree differences in water status were large enough to obscure irrigation treatment effects. Hence, in the absence of a plant-based measure of water stress, it may be difficult to determine whether the lack of an irrigation treatment effect indicates the lack of a physiological response to plant water status, or rather is due to treatment ineffectiveness in influencing plant water status. These data indicate that stem water potential can be used to quantify stress reliably and guide irrigation decisions on a site-specific basis.
A Comparison of Seeding Rate, Spacing, and Weed Control Methods in the Virginia Tech Transplanted Meadow
Authors: Harkess Richard L. , Lyons Robert E.
Published: December 2018

Combinations of seeding rate, spacing, and weed control treatments were evaluated for their effect on the performance of the Virginia Tech transplanted meadow technique. The treatments consisted of seeding at 112 or 56 g·90 m−2; within-row transplant spacing of 30, 45, or 60 cm; and mulching, oryzalin application, or no weed control measures. Plant competition alone was insufficient, whereas oryzalin was the most effective for weed control but also reduced the plant stand and floral display. Mulch provided effective weed control with maximum floral display. Close transplant spacing within rows resulted in quick site coverage initially, but this advantage disappeared after 8 weeks compared to wider spacing. Seeding rate did not affect site coverage until the meadow reached maturity at 12 weeks. The lower seed rate allowed more lodging, resulting in a more open appearance and greater canopy light transmission. Chemical name used: 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin).
Photoperiod of Poinsettia Stock Plants Influences Rooting of Cuttings
Authors: Roll Michael J. , Newman Steven E.
Published: December 2018

Rooting of cuttings from three cultivars of Euphorbia pulcherrima Willd. was evaluated after regulating the photoperiod during the stock plant stage. One group of stock plants was exposed to a night break (4 hours) and another group was exposed to natural daylength during September. Cuttings harvested in late September from `Freedom Red' and `Monet' stock plants grown under the 4-hour night break rooted more rapidly and had greater root mass than `Freedom Red' and `Monet' grown under natural daylength, whereas rooting of cuttings from `V-17 Angelika Marble' was not influenced by the photoperiods tested. Using a night break to prevent flower initiation of stock plants produced a higher-quality cutting when propagation took place after the critical daylength for flowering had passed.
Effects of Cooling by Over-tree Sprinkler Irrigation on Fruit Color and Firmness in `Sensation Red Bartlett' Pear
Authors: Dussi Maria Claudia , Sugar David , Azarenko Anita Nina , Righetti Timothy L.
Published: December 2018

Over-tree sprinkler irrigation cooling treatments were applied to `Sensation Red Bartlett' pear trees during the final 30 days of fruit maturity in 1992 and 1993 when orchard air temperatures were >29 °C. Fruit from cooled trees were more red and less yellow than fruit from noncooled trees, resulting in lower hue values by the middle of the harvestable maturity period in both years of study. In 1992, cooled fruit had a greater portion of the fruit surface covered with red blush than fruit that were not cooled. Fruit firmness decreased more rapidly in fruit from cooled trees than in fruit from noncooled trees, indicating advanced maturity. Accordingly, cooled fruit should be harvested earlier than noncooled fruit to maintain postharvest quality. Differences between cooled and noncooled fruit with respect to hue, surface blush, and rate of firmness loss were more pronounced in a warm season requiring frequent cooling than in a cooler season.
Release Rates of Controlled-Release and Soluble Magnesium Fertilizers
Authors: Broschat Timothy K.
Published: December 2018

Release rates at 21 °C were determined in sand columns for 12 commercially available soluble and controlled-release Mg fertilizers. Lutz Mg spikes, K2SO4, MgSO4, MgSO4·H2O, and MgSO4·7H2O released their Mg within 2 to 3 weeks. Within the first 6 weeks, MgO·MgSO4 released its soluble Mg fraction, but little release occurred thereafter. Dolomite and MgO released <5% of their Mg over 2 years while MagAmp released <20% of its Mg. Florikan 1N-0P-26K-4Mg types 100 and 180 exhibited typical controlled-release fertilizer characteristics, with most of their Mg release occurring during the first 15 weeks.
An Empirical Approach for Detecting Crop Water Stress Using Multispectral Airborne Sensors
Authors: Clarke Thomas R.
Published: December 2018

Irrigation scheduling can be improved by directly monitoring plant water status rather than depending solely on soil water content measurements or modeled evapotranspiration estimates. Plants receiving sufficient water through their roots have cooler leaves than those that are water stressed, leading to the development of the crop water stress index, which uses hand-held infrared thermometers as tools for scheduling irrigations. However, substantial error can occur in partial canopies when a downward-pointing infrared thermometer measures leaf temperature and the temperature of exposed, hot soil. To overcome this weakness, red and near-infrared images were combined mathematically as a vegetation index, which was used to provide a crop-specific measure of vegetative cover. Coupling the vegetation index with the paired radiant surface temperature from a thermal image, a trapezoidal two-dimensional index was empirically derived capable of detecting water stress even with a low percentage of canopy cover. Images acquired with airborne sensors over subsurface drip-irrigated muskmelon (Cucumis melo L.) fields demonstrated the method's ability to detect areas with clogged emitters, insufficient irrigation rate, and system water leaks. Although the procedure needs to be automated for faster image processing, the approach is an advance in irrigation scheduling and water stress detection technology.
Problems Identifying Japanese Cedar Cultivated in the United States
Authors: Rouse Robert J. , Fantz Paul R. , Bilderback Ted E.
Published: December 2018

Japanese cedar [Cryptomeria japonica (Thun. ex L.f.) D. Don. (Taxodiaceae)] cultivars have become quite popular in the U.S. landscape and nursery industries. Their popularity is expected to increase as more attractive and adaptable horticultural selections gain recognition. Taxonomic problems include an inadequate inventory of selected variants cultivated in the United States, instability of names at the infraspecific taxonomic level, poor descriptions of the cultivars, and a lack of representative specimens and identification aids to help horticulturists identify unknown specimens. A study of Cryptomeria japonica cultivated in the United States is needed to address these problems.
Composted Poultry Litter as Potting Media does not Affect Transplant Nitrogen Content or Final Crop Yield
Authors: Guertal E.A. , Behe B.K. , Kemble J.M.
Published: December 2018

The use of composted waste materials as an alternative source of potting media has received much interest in recent years. Our objective was to incorporate composted, ground poultry litter into a standard greenhouse potting mix, and evaluate the effect of the poultry litter on vegetable transplants grown in the greenhouse and transplanted to the field. Treatments consisted of potting mixes of 100% potting media or 50/50 media/poultry litter. Collards (Brassica oleracea L. var. acephala DC.), broccoli (Brassica oleracea var. italica Plenck.), cabbage (Brassica oleracea L. var. capitata L.) and three tomato (Lycopersicon esculentum Mill.) cultivars were utilized as test crops. A nutrient solution treatment of 8 oz of 8N-11P-7K fertilizer or 8 oz of water was added when transplants were set in the field. Plant weight and nitrogen content were measured weekly during the greenhouse production stage, and final crop yield was recorded at harvest. Any effect from the inclusion of poultry litter in the potting media on cole crop (collards, broccoli, cabbage) transplant dry weight had disappeared by the fourth week of sampling in the greenhouse, and final yield of cole crops was unaffected by either type of potting mix or presence or absence of starter nutrient solution. Dry weight of tomato transplants was not affected by type of potting media. Differences in tomato yield due to type of potting mix were observed, as plots with transplants grown in the 50/50 mix had greater nonmarketable yields (`Bonnie' and `Big Boy'). Yield of `Big Boy' tomato was increased by the addition of starter nutrient solution. It appears that composted, uniformly prepared waste materials are suitable for production of vegetable transplants.
Sunny Hollow Orchard: A Decision Case as a Basis for Classroom Discussion
Authors: Foulk Doug S. , Hoover Emily E.
Published: December 2018

This decision case concerns the need to make management decisions in a commercial apple orchard planted largely with `Haralson,' a russet-susceptible cultivar. The growers described in this situation had to decide whether applying GA4+7 for russet suppression was appropriate for their operation, given the financial, cultural and pesticide issues that required addressing. The case is intended for use in fruit production or other intermediate to advanced undergraduate horticulture courses and assumes a knowledge of basic perennial-crop production practices. Students assume the role of a decisionmaker in the complicated issue of orchard management.
Health Functionality of Blueberries
Authors: Kalt Willy , Dufour Dominique
Published: December 2018

Blueberries (Vaccinium sp.) have a long history of use in native and folk medicine in North America and Europe. Today the European blueberry (bilberry) is used in a variety of pharmaceutical and food supplement products that are recommended for treating blood vessel disorders and ophthalmological conditions. Anthocyanins, the pigments that impart the blue color to blueberries, are considered the active ingredient in bilberry health products, although other related flavonoids are biomedically useful. Vaccinium flavonoids are antioxidants and are also recognized for their anticarcinogenic properties and usefulness in treating urinary tract infections. The most immediate, and perhaps greatest, opportunity for a health market for North American blueberries may be in promoting blueberries as a healthy food. As researchers continue to explore the biomedical usefulness of blueberries, the blueberry food industry should strive to retain the healthful phytochemical in their products.
Efficacy of Ancymidol, Paclobutrazol, and Uniconazole on Growth of Tuberous-rooted Dahlias
Authors: Whipker Brian E. , Hammer P. Allen
Published: December 2018

Plant growth retardant (PGR) substrate drench treatments (mg a.i./1.5-L pot) of ancymidol at doses of 0.5 to 8, paclobutrazol from 1 to 16, and uniconazole from 0.125 to 2 were applied to tuberous-rooted dahlias (Dahlia variabilis Willd.) to compare their effectiveness for controlling height. When the first inflorescence opened, the number of days from potting until flowering, leaf canopy height, inflorescence height above the foliage, and plant diameter were recorded. Total height control achieved using PGRs was primarily due to reduced inflorescence height, rather than leaf canopy height. Paclobutrazol, ancymidol, and uniconazole at all doses reduced total plant height of the less-vigorous `Red Pigmy' by >21% compared to the untreated control, with a height of 43.5 cm for the untreated control plants. Marketable potted plants were produced with doses of 2 to 4 mg of paclobutrazol, 0.25 to 0.5 mg of uniconazole, or 0.5 mg of ancymidol. All paclobutrazol, ancymidol, and uniconazole doses reduced total plant height of the more-vigorous `Golden Emblem' by >11% compared to the untreated control, with a height of 82.1 cm for the untreated control. Marketable potted plants were produced with 4 to 8 mg of paclobutrazol, 0.5 to 1 mg of uniconazole, or 2 mg of ancymidol.
The Florida Master Gardener Program: History, Use, and Trends
Authors: Ruppert Kathleen C. , Bradshaw Joan , Stewart Arlene Z.
Published: December 2018

The Florida Master Gardener program volunteered more than 730,865 service hours to the Florida Cooperative Extension Service from 1991 through 1996, valued as a net in-kind donation of $4,615,395. Started in 1979, this program has grown consistently, affecting Floridians in all walks of life. Agents in 47 counties devoted an average of 29% of their time to capitalize on this volunteer knowledge and expertise. An overview of Florida's Master Gardener program provides a synopsis of the many components that make this volunteer program a success including past trends and current areas of review to prepare the program for the next millennium.
Master Gardener Training Costs and Payback in Volunteer Hours
Authors: Meyer Mary Hockenberry , Hanchek Anne M.
Published: December 2018

The Master Gardener (MG) program operates in conjunction with the cooperative extension service in most states. The training, management, and administration of these volunteers vary widely from state to state. This paper presents a 4-year analysis of the initial cost of training Minnesota MGs and their volunteer hours contributed to the Minnesota Extension Service. The average training cost was $89/person (based on the total number of volunteers certified 2 years after the training) with an average of 59 ($711 at $12/h) and 40 ($474) hours volunteered or paid back over the first and following years, respectively. In all years, hours volunteered exceeded program expectations of 50 hours the first year and 25 hours thereafter.
Quantifying the Effect of Plug-flat Color on Medium-surface Temperatures
Authors: Faust James E. , Heins Royal D. , Shimizu Hiroshi
Published: December 2018

Medium-surface temperature of black, gray, and white plug sheets was measured with thermocouples and an infrared camera. During the night, there were no medium-surface temperature differences between the plug flats; however, medium-surface temperature was 2 to 3 °C below air temperature. Medium-surface temperature increased as solar radiation (280 to 3000 nm) increased. About 80 W of solar radiation/m2 was incident on the plug-flat surface before medium-surface temperature equaled air temperature. Medium-surface temperature in the black, gray, and white flats was 6.3, 6.1, and 5.3 °C above air temperature, respectively, when 300 W of solar radiation/m2 (30% of the maximum solar radiation during the summer) was incident on the medium surface. Thus, incident solar radiation has a greater effect on medium surface temperature than plug-flat color.
Applications of Endothalic Acid, Pelargonic Acid, and Hydrogen Cyanamide for Blossom Thinning in Apple and Peach
Authors: Fallahi Esmaeil
Published: December 2018

Blossom thinning of `Early Spur Rome' apple (Malus domestica Borkh.) and `Redhaven' peach (Prunus persica L.) with hydrogen cyanamide (Dormex, 50% a.i.), endothalic acid [(Endothal, 0.4 lb a.i./gal (47.93 g a.i./L)], and pelargonic acid (Thinex, 60% a.i.) was studied in 1995 and 1996. Full-bloom applications of hydrogen cyanamide at 2 pt formulation/100 gal (1288 mg a.i./L) and 2.5 pt formulation/100 gal (1610 mg a.i./L) or endothalic acid at 1 pt formulation/100 gal (59.9 mg a.i./L), once at 70% bloom and again at full bloom, reduced apple fruit set. Pelargonic acid was only effective in thinning apple blossoms when applied twice—at 40% bloom and again at full bloom—at 1.5 pt formulation/100 gal (1.12 mL a.i./L) per application. Pelargonic acid marked apples in 1995 but not 1996. Neither hydrogen cyanamide nor endothalic acid marked apples. A single full-bloom application of hydrogen cyanamide, endothalic acid, or pelargonic acid effectively thinned peach blossoms in 1995; however, in 1996, only hydrogen cyanamide at 2.5 pt formulation/100 gal effectively thinned peach blossoms. Peaches did not show fruit marks with any of the peach blossom thinners.
Response of Bean and Broccoli to High-sulfate Irrigation Water
Authors: Drost D.T. , MacAdam J.W. , Dudley L.M. , Soltani N.
Published: December 2018

Groundwater contaminated with sulfate (SO42−) at concentrations greater than allowed for drinking water may be suitable for irrigation. Our objectives were to determine the growth response and mineral uptake of two vegetables grown with high SO42− irrigation water. Bean (Phaseolus vulgaris) and broccoli (Brassica oleracea L.) were grown in a calcareous sandy loam soil irrigated with water containing 175 to 1743 mg SO42−/L. Plants were harvested and growth was measured at 4, 8, or 12 weeks. Soil paste and dried ground plant tissue extracts were analyzed for elemental composition at each harvest by inductively coupled plasma spectroscopy. Bean shoot dry mass decreased as SO42− concentration increased. Although pod number at 4 weeks decreased as SO42− concentration increased, pod number at 12 weeks was not affected by irrigation treatments. Broccoli growth was not affected by increasing SO42− concentration at any of the harvest dates, although head diameter decreased as SO42− increased. Magnesium, sodium, and sulfur accumulated in shoot tissue (leaves and stems) of both species in proportion to their concentration in the irrigation water. Soil Na and electrical conductivity levels increased as SO42− concentration increased even with a 20% leaching fraction. These results suggest that bean and broccoli can be successfully grown with high-SO42− irrigation water.
A Rapid Nondestructive Technique to Predict Leaf Nitrogen Status of Grapefruit Tree with Various Nitrogen Fertilization Practices
Authors: Li Y.C. , Alva A.K. , Calvert D.V. , Zhang M.
Published: December 2018

The objective of this study was to evaluate the use of a leaf chlorophyll meter (SPAD-502) to predict nitrogen status and yield response of grapefruit trees. The study included two irrigation treatments, three sources, and four rates of fertilizer [dry soluble granular fertilizer broadcast or through fertigation with N rates either 50, 100, 150 lb/acre/yr (56, 112, or 168 kg.ha-1.yr-1)], and controlled-release fertilizer with N rates either 25, 50, 100 lb/acre. Irrigation treatments did not affect SPAD readings and leaf N concentrations. Correlations between SPAD readings and leaf N were greater for the spring flush (r2 = 0.61) than for the summer flush (r2 = 0.49). High correlations of SPAD meter readings with either fruit yields or leaf N suggests that SPAD meter reading is an acceptable index of N status and fruit production of the trees. SPAD readings can be made rapidly without destructive sampling of the leaves. This study demonstrates that the SPAD meter can be used to evaluate the tree N status and improve a N fertilization program for grapefruit trees.
Extension Outreach: Improving Vegetable Handling and Storage Systems in Russia
Authors: Rushing James W. , Christenbury Gerald D.
Published: December 2018

Through an agency called Volunteers for Overseas Cooperative Assistance (VOCA), funded primarily by the U.S. Agency for International Development (USAID), professionals from many disciplines are recruited to assist less-developed countries (LDCs) with establishing new industries and/or improving management practices in existing businesses. We were recruited to evaluate the causes of postharvest losses of horticultural products in Russia. These losses historically have been high due to the limited availability of mechanical refrigeration and poor postharvest management practices. This paper reports on the success of an extension demonstration project in Russia where traditional storage and handling systems for carrots were compared to systems using improvements in grading and prestorage sanitation. An evaluation of storage facilities and recommendations for improvements are discussed.
Evaluating Biorational Pesticides for Controlling Arthropod Pests and their Phytotoxic Effects on Greenhouse Crops
Authors: Miller Fredric , Uetz Susan
Published: December 2018

Horticultural oil and insecticidal soap were as effective as conventional insecticides and miticides in controlling a variety of sap-feeding insects and mites on common greenhouse crops. Neem extract (Margosan-O or Azatin) was less consistent and provided intermediate to good control of a variety of sap-feeding insects and mites on common greenhouse crops. Except for purple heart (Setcreasea purpurea K. Schum. & Sydow) and wax ivy (Hoya carnosa R. Br.), repetitive sprays of horticultural oil, insecticidal soap, and neem extract (Azatin) did not seem to cause any noticeable phytotoxicity or effect the growth of 52 species or cultivars of bedding plants and 13 species of foliage plants examined in this study. Repetitive sprays of horticultural oil and insecticidal soap significantly affected plant height and final quality of some poinsettia cultivars evaluated in this study.
Effects of Controlling pH with Hydrochloric Acid on the Growth, Yield, and Fruit Quality of Greenhouse Tomato Grown by Nutrient Film Technique
Authors: Papadopoulos A.P. , Pararajasingham S.
Published: December 2018

In growing greenhouse tomato (Lycopersicon esculentum Mill.) using the nutrient film technique (NFT), HNO3 or H3PO4 is usually added to offset the increase in pH of the recirculating solution. For economic and environmental reasons, HCl would be a possible substitute for either HNO3 or H3PO4. Therefore, experiments were initiated to evaluate HCl as an alternative acid in controlling the pH of the recirculating solution in NFT-grown greenhouse tomato. The effects of HNO3, H3PO4, and HCl on the growth, fruit yield, and fruit quality were quantified. In 1995, these effects were tested using `Trust' and `BST 7804' at a recirculating solution pH of 5.5, 6.0, or 6.5; in 1996, only `Trust' was grown at a recirculating solution pH of 6.2. In the 1995 experiment, genotypic differences in marketable fruit yield tended to be smaller when HCl was used to control the recirculating solution pH at 6.0 than when either H3PO4 or HNO3 was used. In `Trust', at a pH of 5.5 under the HCl treatment, fruit quality tended to be higher than in other treatment combinations. In 1996, over a 45-day period, the concentration of Cl− that accumulated in the recirculating solution from added HCl was 313 mg·L−1 (313 ppm). There were no significant effects of the treatments on the growth, fruit quality, or yield of the crop. The total marketable yield was better when HCl had been used, likely due to high fruit production at the early part of the harvesting period. Potential savings for the season can be achieved if HCl is substituted for H3PO4 to regulate the nutrient solution pH in NFT-based greenhouse tomato production.
Determining Poinsettia Nitrogen and Sulfur Fertilizer Application Rates Based on Chromometer and Sensory Panel Ratings
Authors: Adams Stacy A. , Paparozzi Ellen T. , Stroup W.W.
Published: December 2018

`Dark Red Annette Hegg' poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch) were grown in a 1 peat : 1 perlite : 1 vermiculite medium using a pinched production schedule with varying N and S fertilizer application rates. Fifty-six treatments consisting of eight N levels (100 to 275 mg·L−1 in 25-mg·L−1 increments) and seven S levels (0 to 75 mg·L−1 in 12.5-mg·L−1 increments) were supplied. Other required nutrients were supplied at commercial recommendations for all treatments. Foliage of each plant was evaluated quantitatively by chromometer readings every 3 weeks. Marketability was determined by sensory evaluations from commercial producers, retailers, and consumers. Results indicated distinct color differences (hue, chroma, value) between S levels of 0 and 12.5 mg·L−1 and a slight difference between S at 12.5 and 25 mg·L−1. The foliage of plants receiving 0 S was lighter, more vivid, and more yellow-green in color. As N levels increased, there was a linear response; foliage became more green, darker, and more dull. Commerical and consumer evaluators rated plants that received S at 0 or 12.5 mg·L−1 at all N levels and plants receiving N at 100 mg L−1 as unmarketable. This research indicates that `Annette Hegg' poinsettia requires S at a minimum of 25 mg·L−1 and N at a minimum of 125 mg·L−1 for commercial acceptance, and commercial N application rates may be greatly reduced when adequate S is supplied.
Crop Rotation Reduces the Cost of Colorado Potato Beetle Control in Potatoes
Authors: Speese John , Sterrett S.B.
Published: December 2018

The effect of crop rotation was investigated on the efficacy and the economics of various insecticide strategies for Colorado potato beetle (CPB) control in potatoes (Solanum tuberosum L.) in 1995-96. These included broad-spectrum insecticides and biorational (environmentally friendly, naturally occurring) combinations that targeted specific CPB life stages. CPB pressure was greater in the nonrotated than the rotated plots. Although all materials gave better CPB control than the check, significantly more spray applications were required to reduce CPB numbers below treatment thresholds in the nonrotated plots than the rotated plots in both years. Overall yields and economic returns were significantly greater in the rotated plots in 1995. Efficacy of insecticide strategies varied, with little defoliation and few CPB larvae found in the imidacloprid treatment in 1995 and 1996. All insecticide strategies except endosulfan resulted in significantly higher estimated returns to management than the untreated check; the greatest returns occurred with permethrin and cryolite. No yields or returns could be obtained in 1996 due to excessive rainfall before harvest. These results indicate that yield and the cost of the insecticide strategy should be considered as well as insecticide efficacy in developing an effective integrated pest management program.
Developing, Converting, and Maintaining Information-rich Resources on the World Wide Web
Authors: Peet Mary M.
Published: December 2018

Sustainable Practices for Vegetable Production in the South, 174 pages long and with 250 references, was written as a traditional college textbook, but is also available as a World Wide Web (Web) site (http://www2.ncsu.edu/sustainable/). This article chronicles the conversion of the entire text to a Web document and the simultaneous release of Web and print versions. I will also discuss some of the issues that we will confront if we depend on the Web for delivering and receiving content-rich information. These issues are as follows. 1) Although there are no standards for Web sites as there are for print documents, there are certain similarities in the way most Web sites function. Relative to our familiarity with book and journal conventions, those of us educated in the age of print are unaware of Web standards. 2) The optimal size and structure of the information chunk is unclear. Should it be a whole chapter or article, a single paragraph, or a functional unit of facts that doesn't have a name or correspond to anything in print media? 3) Organization and consistency are critical. Table and chapter numbers are meaningless. The most important question is “How does a person accessing part of your Web site know about all the other parts and how they fit together?” You can flip through a book to view it, but a person following a link to a particular page on your site is like the blind man touching the elephant's trunk—the whole is hard to visualize. 4) There is no good place to put references and footnotes because of the subdivision of information into chunks of functional facts. 5) There is no obvious starting or stopping point in making revisions. 6) People accessing the site will send messages and ask questions.
The Role of ASHS in Implementing HortBase
Authors: Emely Charles H.
Published: December 2018

ASHS is the largest worldwide professional scientific society for the horticultural science community. Research presented in the serial publications of the society is peer-reviewed under a well-organized and rigorous system that provides independent review of the research and ensures that the scientific information published is validated. The ASHS Executive Committee and Board of Directors are firmly committed to the HortBase concept of information dissemination and are supportive of the society's proposed role as the validator of HortBase information for use in extension and teaching. The presentation will discuss the role of the scientific society, specifically ASHS, in implementing HortBase.
Agricultural Databases for Decision Support
Authors: Eastwood Basil R.
Published: December 2018

Several factors have emerged recently, have grown in importance, and are now converging rapidly to create a window of opportunity for all of us. These factors constitute six separate but related and important categories: 1) decreasing staff in the U.S. cooperative extension system, 2) increasing complexity of agricultural production technologies, 3) increasing concerns of society, 4) opening of markets globally, 5) increased need for accountability, and 6) rapid progress in computerized information and communication technologies. These factors encourage greater sharing of expertise and resources across states, institutions and departments; more cooperation with the private sector; improved openness and communication on issues of interest to society; greater awareness of our role in the world; and a willingness to consider new approaches. A program approach and model competitively funded program for the future are described.
Survey on the Needs of Elementary Education Teachers to Enhance the Use of Horticulture or Gardening in the Classroom
Authors: Dobbs Kathleen , Relf Diane , McDaniel Alan
Published: December 2018

To determine if and how plant materials were used in Virginia elementary school curricula, a survey was conducted on horticulture or gardening in elementary [Kindergarten-sixth grade (K-6)] education. To do this, 10 questionnaires and cover letters were sent to each of 100 randomly chosen elementary schools throughout Virginia. Based on a 34% response rate from a self-selected group of K-6 teachers, there was a relatively high level of interest (88%) regarding using horticulture or gardening in the classroom. A major goal of this survey was to determine what would encourage or facilitate incorporating horticulture or gardening into the curriculum.
Growth of Tomato and Coreopsis in Response to Coir Dust in Soilless Media
Authors: Pill Wallace G. , Ridley Karen T.
Published: December 2018

We examined the efficacy of coir dust (CD)—the short fibers and dust from the mesocarp of coconuts (Cocos nucifera L.)—as an alternative to sphagnum peat (SP) in 50 SP : 50 vermiculite (% volume) medium. Shoot dry mass of coreopsis (Coreopsis lanceolata L.) or `Red Robin' tomato (Lycopersicon esculentum Mill.) after 5 weeks' growth in up to 50 CD : 50 vermiculite (% volume) was similar to that in 50 SP : 50 vermiculite and a commercial peat-lite (Pro-Mix BX). These growth responses depended on preplant controlled-release fertilizer (CRF) [Osmocote 17N-3.9P-10.8K at 11.5 lb/yd3 (4 kg·m−3)] and/or a post-transplanting weekly solution fertilization (SF) at 350 ppm (mg·L−1) N from 21N-2.2P-16.6K. Compared to SP, CD had lower bulk density and cation exchange capacity (volume basis) and higher C to N ratio, pH, total porosity, and container capacity. We conclude that CD is an adequate alternative to SP in soilless container media.
Practical Training in Horticultural Undergraduate Courses: Understanding Job Opportunities and Availability through a Study Tour of Alumni
Authors: Cantliffe Daniel J. , Kostewicz Stephen R.
Published: December 2018

For many years, the former Vegetable Crops Department, now the Horticultural Sciences Department, at the University of Florida offered a vegetable crop industries course. This one-credit course is offered each year as a 3- to 5-day field trip into vegetable production areas of Florida in the spring semester during spring break. The intent of the course is to give undergraduate students an extensive on-site evaluation of the application of scientific principles learned in lectures related to Florida's commercial vegetable industry. A new, innovative approach to structuring this course was initiated recently wherein only alumni of the department interacted with the students on all phases of commercial vegetable agriculture in Florida. These alumni had obtained degrees at the BS, MS, or PhD level and represented many professional backgrounds related to producing, handling, and marketing vegetables. Students were exposed to real-life situations and were encouraged to discuss and seek employment opportunities during the farm visitations. Student expenses were offset by donations from the Florida vegetable industry.
Root and Shoot Modification by Irrigation
Authors: Leskovar Daniel I.
Published: December 2018

Irrigation methods, rates, timing, and frequency may influence the physical and chemical properties of the growing media thereby affecting root initiation, elongation, branching, development and dry matter partitioning between roots and shoots.
Mechanical Conditioning to Control Height
Authors: Latimer Joyce G.
Published: December 2018

Mechanical conditioning is an excellent means of regulating the growth of vegetable transplants and some ornamental bedding plants. It improves the stature, appearance, handling characteristics, and overall quality of treated plants. The application procedures reported for transplants have included wind, shaking, brushing, and more recently impedance; all of which result in physical displacement of the growing points. Brushing has been most commonly studied for mechanical conditioning in high density transplant production. Brushing reduces plant height, increases stem and petiole strength, improves insect resistance in the greenhouse, tends to improve stress tolerance and enhance stand establishment in the field, and has no effect on crop yield. Although growers using the technique have been very pleased with the quality of brushed vegetable transplants, widespread commercial application of brushing is limited by a lack of automation.
Endocarp Removal Enhances Butia capitata (Mart.) Becc. (Pindo Palm) Seed Germination
Authors: Broschat Timothy K.
Published: December 2018

Germination rate was significantly improved by removing the thick, hard endocarp from Butia capitata (pindo palm) fruit. Time to 50% of final germination rate was not affected by endocarp removal. Afterripening storage did not improve germination rate or time. Germination at 104 °F (40 °C) was superior to that at 93 °F (34 °C).
Effects of Mulch on Soil Moisture and Growth of Desert Willow
Authors: Kraus Helen Tyler
Published: December 2018

The objective of this research was to consider the effects of gravel, wood chip, and tire mulches and turf on soil moisture and root and shoot growth of Chilopsis linearis (Cav.) `Burgundy' (desert willow). Gravel, wood chip, and tire mulches retained greater soil moisture than bare soil (control) with little difference in soil moisture between the mulches. Mulched trees and bare soil had greater height and shoot and root dry weights than trees in turf. Turf conserved soil moisture better than bare soil but appeared to compete with desert willow for water and nutrients resulting in less growth. Trees with gravel and tire mulches had greater shoot dry weight in the second year of growth and greater root dry weight, root length, and root area in both the first and second years of growth after transplanting.
Paclobutrazol Drench Activity in Coir- and Peat-based Root Substrates
Authors: Dasoju Shravan , Evans Michael R. , Whipker Brian E.
Published: December 2018

Paclobutrazol drench applications of 0, 2, and 4 mg a.i./pot were applied to `Pacino' potted sunflowers (Helianthus annuus L.) and `Red Pigmy' tuberous rooted dahlias (Dahlia variabilis Willd.) grown in substrates containing 50%, 60%, 70%, or 80% (by volume) sphagnum peat or coir, with the remainder being perlite, to study the efficacy of paclobutrazol (Bonzi). Potted sunflower plant height differed significantly for peat- and coir-based substrates, with greater plant height being observed in coir-based substrates. Plant diameter was significantly greater at higher percentages of peat or coir in the substrate at 2 and 4 mg of paclobutrazol. Inflorescence diameter also was significantly decreased as paclobutrazol concentration increased. When the percent of height control from the untreated plants for potted sunflower was compared between coir and peat-based substrates, the percent height reduction was similar for peat- and coir-based substrates at 2 mg of paclobutrazol and height control was greater at 4 mg of paclobutrazol in coir-based substrates. The differences in plant growth observed in peat- and coir-based substrates can be attributed to differences in physical properties of these substrates. Dahlia plant height, diameter, and number of days until anthesis were not influenced by substrate type or percentage. However, dahlia growth was significantly reduced as paclobutrazol concentration increased. Coir-based substrates did not reduce the activity of paclobutrazol drenches compared to peat-based substrates, although to compensate for the greater amount of plant growth in coir-based substrates, paclobutrazol concentrations may need to be increased slightly to achieve a similar plant height as with peat-based substrates.
Penetrometric Measurement of Strawberry Fruit Firmness: Device Testing
Authors: Hietaranta Tarja , Linna Minna-Maria
Published: December 2018

The firmness of five strawberry (Fragaria×ananassa Duch.) varieties was determined by penetrometric method using a motorized materials testing device equipped with a 100-N load cell and a probe 6.4 mm (0.252 inches) in diameter. Maximum and mean forces and instant of yield point were recorded with the aim of testing the suitability of these three parameters for the assessment of fruit firmness, i.e., handling and transportation tolerance. The maximum and mean force data revealed significant differences among varieties, but instant of yield point was not reliable measurement in this test arrangement. Maximum force was the best parameter for the assessment of firmness.