bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Wind and Soil Moisture on the Growth of `Bluecrop' (Vaccinium corymbosum L.)
Authors: Erb W. Alan , Pyeatt Mark
Published: February 2019

This study was conducted in the greenhouse by running two experiments at different temperature regimes (22°C day and 13°C night and 33°C day and 22°C night). One-year-old tissue culture propagated plants were irrigated at three different soil moisture tension levels (5, 15, and 30 cnbars) and either exposed to moving or still air. The moving air treatment was created by two 51-cm-diameter fans running at either low (5.6 mph) or medium (8.2 mph) speed. Each experiment included, forty-eight plants arranged in a randomized complete block design. Each block consisted of a greenhouse bench containing two fans, a plastic dividing wall and two plant replications for each treatment. Canopy volume measurements were taken at the beginning, middle and end of each experiment to estimate growth rate. At the end of each experiment, total leaf area and leaf, stem and root dry weight data were collected. In the moderate temperature experiment, the still air treated plants had the highest canopy volume and leaf weight ratio while the moving air treated plants had the highest stem weight ratio. The only difference for the moisture treatments was the 5-cnbar treatment had the highest canopy volume. In the high temperature experiment, the still air treated plants had the highest canopy volume, total leaf area, leaf dry weight, shoot/root ratio, leaf weight ratio and leaf area duration while the moving air treated plants had the highest root weight ratio. The 5-cnbar treatment had the highest canopy volume and biomass accumulations. The 30-cnbar treatment had the highest root weight ratio.
Consumer Perceptions and Expectations of Garden Center Quality
Authors: Hudson Jay T. , Behe Bridget K. , Ponder Harry G. , Barrick William E.
Published: February 2019

We compared service quality perceptions and expectations for consumers from five traditional garden centers (TGC) and three nontraditional garden center outlets (NTO) in Charlotte, N.C., in 1995. NTO and TGC customers had very similar expectations of service quality from their respective retailers. However, TGC customers perceived that their retailer better met their overall expectations. Service quality gaps, the difference between customer perceptions and expectations, were identified for both types of outlets for four of five service quality dimensions. Both TGC and NTO customers ranked assurance and responsiveness as the most important service quality dimensions. Empathy was more important than reliability to TGC customers. This order was reversed for NTO customers. Both sets of customers ranked tangibles as the least important service quality dimension.
Controlling Circling Roots in Container-grown Ornamentals with Root-inhibiting Herbicides
Authors: Kuhns Larry J. , Harpster Tracey , Elmore Clyde
Published: February 2019

SpinOut is a commercial product containing copper hydroxide that is designed to prevent the development of circling roots in container grown ornamentals. Our objective was to determine the effect of two root-inhibiting herbicides (oryzalin and trifluralin) on the development of circling roots in container grown ornamentals when painted onto the inside surface of the containers or on stakes inserted around the walls of the containers. Rooted cuttings of wintercreeper euonymus (Euonymus fortunei Hand.-Mezz) were planted in a 1 peat: 1 perlite: 1 soil mix on 8 to 10 Feb. 1995. There were 16 containers for each of 20 treatments. Eight were rated for circling roots then harvested 17 to 22 May, and eight were rated and harvested 6 to 7 July 1995. Root circling was rated on a scale of 1 to 5, with 1 indicating no circling roots and 5 indicating many circling roots. Following harvest stem growth was measured and the dry weights of the roots, stems, and leaves were determined. Treated stakes did not prevent circling roots Trifluralin in Vapor Gard reduced the amount of circling roots, but not to acceptable levels. Trifluralin in latex paint was ineffective at 0.5%, slightly reduced the development of circling roots at 2%, and at 4% reduced circling rooting to the same extent as the SpinOut. Surflan at 0.5% in Vapor Gard reduced the development of circling roots to the same extent as the SpinOut. All other rates of Surflan, in both carriers, almost totally eliminated circling roots. There were no significant differences in root weight or total plant weight among any of the treatments at either date of evaluation.
The Effect of Calcium Treatments on the Incidence of Gray Mold Rot in Three Tomato Cultivars
Authors: Calhoun Lori D. , Conway William S. , Sams Carl E.
Published: February 2019

Due to the declining availability of fungicides for use in commercial tomato production, there is a need to investigate alternative disease control methods. Several theories of disease resistance are associated with an increase in plant tissue calcium content, which has increased resistance of tomato seedlings to bacterial wilt and other diseases. Three tomato cultivars (`Mountain Supreme', `Sunrise', and `Celebrity') were grown in a greenhouse hydroponic system to study the role of Ca in reducing decay of fruit by Botrytis cinerea. Calcium treatments of 20, 200, or 1000 ppm were applied in a modified Hoagland's solution. A 3 × 3 factorial randomized complete-block design was used. Mature whole leaves were collected from immediately below the third flower clusters and the calcium content analyzed by inductively coupled plasma emission spectrophotometry. Harvested fruit were inoculated with a 5 × 105 spore/ml conidial suspension of B. cinerea and the decay lesion diameter measured once daily for 7 days. This was repeated for 8 consecutive weeks. Leaf Ca content significantly increased (P < 0.01) as the Ca treatments increased from low to medium (310%) and from medium to high (150%). The medium and high Ca treatments significantly reduced the area of decay caused by gray mold rot (P < 0.01). There were no differences in Ca content or decay among cultivars, and the Ca × cultivar interaction was not significant. It appears that leaf Ca content is negatively associated with resistance of greenhouse-grown tomatoes to gray mold rot, strengthening the hypothesized role of calcium in promoting disease resistance.
Evaluation of Five Different Plant Nutrients for Their Effect on Yield, Quality, and Postharvest Condition of Bell Peppers in a Subtropical Environment
Authors: Brandenberger L.P. , Wiedenfeld R.P. , Makus D.
Published: February 2019

Fertilization programs used commercially for bell peppers (Capsicum annuum) in the subtropical Lower Rio Grande Valley of Texas may vary substantially from recommendations based on research. Therefore, a commercial fertilization program used on a significant fraction of the pepper production in this area was evaluated at two locations. Preplant soil tests showed NO3-N levels were low at one location and very high at the other. Nitrogen application where preplant soil NO3-N was low resulted in a six-fold yield increase (from 197 to 1203 kg·ha–1), and improvements in fruit weight, fruit volume, fruit density, wall thickness, wall strength, and carotenoid and chlorophyll a and b contents. No other nutrient application at either location or N application at the site where preplant soil NO3-N levels were high significantly affected yield by size class, fruit quality characteristics, storage properties, or mineral and organic components. Nitrogen application had the greatest effect on dry-weight accumulation and N uptake during fruit set and maturation when N demand was high. Where N responses were observed, N application increased total dry weight in plant and fruit by 150% and total N uptake by 186%, yet this increase amounted to a N fertilizer uptake efficiency of only 12%. Thus, N should be used judiciously to prevent pollution of drainage and ground waters.
Field Applications of Fungicides Improve Quality and Size of Some Pumpkin Cultivars
Authors: McClurg Charles A.
Published: February 2019

Commercial producers of pumpkin (Cucurbita pepo) in the mid-Atlantic region frequently experience losses of fruit size and quality from the fungal diseases powdery mildew (Erysiphe cichoracearum) and black rot (Didymella bryoniae). In addition to loss of fruit size in some cultivars, the diseases can result in poor quality handles (fruit stems) and pre- and postharvest decay. Since the pumpkins are grown for ornamental use, their appearance, size, and quality are important in marketing strategies. Applications of recommended fungicides during the growing season, although costly, reduce losses in fruit size and quality in susceptible cultivars during years in which the pathogens become established prior to fruit maturity. Larger-fruited cultivars, in general, benefit more from fungicide application than smaller-fruited types in fruit weight, although both benefit in improved handle quality. Cultivars with apparent tolerance to fungal diseases are identified for producers who choose not to use fungicides.
Impact of Pinching Method and Number of Cuttings on Growth of Eight Florist Azalea Cultivars
Authors: Gauthier Fabienne , Dansereau Blanche , Lambert Marie-Josee
Published: February 2019

During Fall 1995–Winter 1996, rooted cuttings of eight Rhododendron Simsii cultivars—Dorothy Gish, Jacinth, Paloma, White Gish, Friedhelm Scherrer, Gloria, Helmut Vogel, and Inga were transplanted July 1995 into 10.5-cm pots. A treatment consisted of one, two or three cuttings per pot. Cuttings were pinched either mechanically using a hedge clipper (control) or chemically with Off-Shoot-O at rates of 63.5 or 111.1 mL·L–1 of water or with Atrimmec at 20 mL·L–1 of water. Pinching treatments were repeated three times during the experimental period. New secondary shoots developed more rapidly after a mechanical pinch than after a chemical pinch. Moreover, greater foliage damage was observed on plants pinched with Off-Shoot-O. Growth measurements (height and diameter of plants, top dry mass, number of days to reach anthesis and visual quality) will be presented.
Control of Flowering in Petunia by Photoperiod and Irradiance
Authors: Karlsson Meriam
Published: February 2019

Petunia `Midnight Madness' plants were grown for 4 weeks starting 3 weeks after seeding, at 8 or 16 hours photoperiod and 3, 7.5, or 12 mol·d–1·m–2. The temperature was 20 ± 1°C throughout the study. The plants were allowed to flower following the 4 weeks photoperiod treatment at 16 hours of 6 mol·d–1·m–2. Petunias grown at long days flowered (first open flower) faster than those exposed to 8 hours day length for 4 weeks. Plants grown at short days required 8 to 10 more days for flowering compared to plants grown at the same irradiance delivered during a 16-hour day. Flowering was first observed 61 ± 0.9 days from seeding for the plants at long days and 12 mol·d–1·m–2. Plants grown at 8 hours and 3 mol·d–1·m–2 required on average 84 ± 0.8 days from seeding to reach flowering. The number of flowers and flower buds (10 ± 1.8 flower buds) was lower for plants grown at 12 mol·d–1·m–2 independent of day length. There were no significant differences in the number of flower buds (16 ± 2.6 flower buds) at termination of the experiment for the plants grown at the two lower irradiance levels for either 8 or 16 hours day length.
Effect of Night-interruption Duration and Cyclic Lighting on Flowering of Obligate Long-day Herbaceous Perennial Plants
Authors: Runkle Erik S. , Heins Royal D. , Cameron Arthur C. , Carlson William H.
Published: February 2019

Six obligate long-day species of herbaceous perennials were grown under six night-interruption treatments to determine their relative effectiveness at inducing flowering. Photoperiods were 9 hours natural days with night interruptions provided by incandescent lamps during the middle of the dark period for the following durations: 0.5, 1, 2, or 4 hours; 6 minutes on, 54 minutes off for 4 hours (10% cyclic lighting); or 6 minutes on, 24 minutes off for 4 hours (20% cyclic lighting). Response to night interruptions varied by species, but five of the six species flowered most rapidly and uniformly under 4-hour night interruption. Few or no Campanula carpatica `Blue Clips', Rudbeckia fulgida `Goldsturm', or Hibiscus ×hybrida `Disco Belle Mixed' plants flowered with 1 hour or less of continuous night-break lighting. All Coreopsis ×grandiflora `Early Sunrise' flowered, but flowering was hastened as the duration of night interruption increased. Echinacea purpurea `Bravado' flowered similarly across all treatments. In general, the effectiveness of the night-interruption treatments at inducing flowering was 4 hours > 2 hours > 20% cyclic > 1 hour > 10% cyclic > 0.5 hour.
Photoperiodic Response of Nine Alternative Hanging-basket Species
Authors: Williams Millie S. , Starman Terri W. , Faust James E.
Published: February 2019

The photoperiodic responses were determined for the following species: Bacopa speciosa `Snowflake', Bidens ferulifolium, Brachycome multifida `Crystal Falls', Helichrysum bracteatum'Golden Beauty', Lysimachia procumbens (Golden Globes), Pentas lanceolata `Starburst', Scaevola aemula `New Blue Wonder', Streptocarpella hybrid `Concord Blue', and Streptosolen jamesonii (Orange Browallia). Each plant species was grown at 8-, 10-, 12-, 14-, and 16-hour photoperiods. Photoperiods were provided by delivering 8 hours sunlight, then pulling black cloth and providing daylength extension with incandescent bulbs. Bacopa speciosa `Snowflake', Bidens ferulifolium, Brachycome multifida `Crystal Falls', Helichrysum bracteatum `Golden Beauty', Scaevola aemula `New Blue Wonder', and Streptocarpella hybrid `Blue Concord' were day neutral, i.e., no difference in days to visible bud or days to anthesis in response to photoperiod were observed. Pentas lanceolata `Starburst' and Lysimachia procumbens (Golden Globes) were quantitative long day plants, i.e., days to anthesis decreased as daylength increased. No difference in days to visible bud, number of lateral shoots, number of nodes, or internode length were observed for Pentas lanceolata `Starburst'; however, days to anthesis for 14- and 16-hour photoperiods occurred 9 days earlier than 8-hour photoperiods. Days to visible bud for Lysimachia procumbens (Golden Globes) occurred 7 days earlier and days to anthesis was 9 days earlier under 14- and 16-hour photoperiods than 8-hour photoperiods. By week 8, only one flower per plant developed in the 8-hour photoperiod while 11 flowers per plant developed in the 14-hour photoperiod. Streptosolen jamesonii (Orange Browallia) was a qualitative short day plant. There was no difference in the days to anthesis between 8- and 10-hour daylength, each averaging 36 days from start of photoperiod treatment. Plants under 12- to 16-hour photoperiods did not flower.
Variation in Lowbush Blueberry Fruit Set and Fruit Characteristics
Authors: Chen Youzhi , Smagula John M. , Litten Walter , Dunham Scott
Published: February 2019

Twenty stems with four fruit buds were tagged in each of ten lowbush blueberry (Vaccinium angustifolium Ait.) clones in a commercial field to assess fruit set and fruit size and weight characteristics. The terminal bud produced the fewest blossoms and fruit but fruit set was equal among all buds (65%–70%). Fruit at bud 4 were slightly smaller in diameter and weighed less than those produced at other buds. Clones with buds producing more blossoms per bud tended to produce more fruit per bud (pearson corr. coeff., r = 0.49), but a stronger correlation was found between fruit set and fruit number (r = 0.81).
Changes in Kinetic Characteristics of the ABA Binding Protein(s) of the Grapevine Fruit during Different Stages of Fruit Development
Authors: Zhang Da-Peng , Zhang Zi-Lian , Chen Jia , Lu Jiang
Published: February 2019

By using the micro-volume radio-ligand binding essay, the changes in the kinetic characteristics of the abscisic acid (ABA)-binding protein(s) of the Kyhoh grapevine (Vitis vinifera × V. labrusca) fruit during the different stages of fruit development have been studied. The changes in the berry volume growth, concentration of sugar, organic acids, and ABA in fruit mesocarp have been surveyed, especially for studies of ABA-binding protein. The dissociation constant (Kd) and ABA binding maximum (Bmax) were determined by the Scatchard plots for ABA binding in microsomes of the fruit. They are Kd = 17.5, 50.0, 6.3, 13.3 nmol·L–1; Bmax = 98.6, 523.0, 41.6, 85.4 μmol·mg–1 protein, respectively, for the fruit developmental phase I, II, veraison, and phase III. The Scatchard plots showed a rectilinear function for all of the developmental phases including veraison, which suggests the sole ABA-binding site of high affinity for ABA in the fruit microsomes, but this site could either be only one kind of the same protein or consist of more kinds of different proteins for different developmental stages. The binding affinity of ABA-binding protein(s) for ABA was shown to be higher at veraison time than during other developmental phases; this binding affinity increased nearly by 10 times from phase II to veraison, while the concentration (Bmax) of the ABA-binding protein(s) decreased to the minimum at veraison. The very low concentration of ABA at veraison may be able to trigger the onset of fruit ripening due to the increase of the binding affinity of ABA-binding protein(s) for ABA at this time. The possible functions of the ABA-binding protein(s) for fruit development during the different developmental stages were discussed, and it is suggested that the protein(s) detected could be the putative ABA receptor(s) or transporter(s) for the action of this plant hormone in grapevine.
Flow Rate as a Major Physiological Factor Influencing Calcium Content on Six Commercial Cultivars of Snap Beans (Phaseolus vulgaris L.)
Authors: Quintana Juan M. , Harrison Helen C. , Nienhuis James , Palta Jiwan P.
Published: February 2019

Flow rate, Ca content, and Ca concentration of sieve sap were measured at four developmental stages (flowering and 1, 2, and 3 weeks after flowering) in six commercial snap bean cultivars to better understand physiological factors associated with genetic differences for pod Ca concentration. Sampling began 5 weeks after greenhouse planting and consisted of 1) decapitation of the plant at the first node; 2) covering the stem with preweighed dry cotton; and 3) removing the cotton, reweighing it, and saving it for Ca determination. Flow rate was defined as the difference in cotton weight (expressed as milliliter) per 12 hours. Ca determinations were made using an atomic absorption spectrophotometer. Calcium content was defined as milligram of Ca per total volume of sieve sap after 12 hours. Concentration of Ca was the quotient of Ca content by flow rate (expressed as milligrams Ca per milliliter sap). A positive correlation between flow rate and total Ca content of sieve sap (R2 = 0.83), flow rate and Ca concentration of sieve sap (R2 = 0.36), and Ca content and Ca concentration (R2 = 0.80) were found. Maturity appeared to be an important factor affecting flow rate and Ca influx in snap bean plants. Significant differences between genotypes for Ca content and flow rate were observed. High Ca genotypes reflected a high flow rate regardless developmental stage.
Comparison of Root Characteristics of Conventionally Grown Cowpeas and Cowpeas Grown without Added Nitrogen Fertilizer
Authors: Kahn Brian A. , Schroeder Judith L.
Published: February 2019

Field experiments were conducted in Oklahoma in 1993 and 1994. Cowpeas [Vigna unguiculata (L.) Walp.] were grown using either non-inoculated seed and 23 kg·ha–1 of preplant nitrogen fertilizer (conventional) or inoculated seed and no preplant nitrogen fertilizer (reduced input). Sample plants were excavated at first pod set and analyzed for nodulation and root morphology. Additional plants were excavated at the green-shell stage and were analyzed for nitrogen concentration. Conventional and reduced input cowpeas did not differ in nodule distribution among root morphological components, total nodule fresh weight, total root dry weight, or nitrogen concentration. Most nodules generally were located on the basal and lateral roots. Results indicate that cowpea root characteristics are not necessarily altered by differing cultural systems at a given location.
The Effect of Plastic Mulch Color on Growth and Development of Cucumber and the Response of Cucumber Beetles to Mulch Color
Authors: Mbugua Irene Nyambura
Published: February 2019

Field experiments were performed to verify the influence of polyethylene mulches (red, blue, gray, black, and yellow) on the development and yield of two varieties of cucumber (Cucumis sativus), a hybrid, `Turbo' and an open-pollinated, `Marketmore 76'. The influence of the mulches on the population dynamics of the adult striped cucumber beetle (Acalymma vittatum) was also observed. Rhizosphere temperature, reflected surface temperatures, reflected wavelength, vine length, leaf number, leaf area, total fruit produced, and number of marketable fruit were some of the characteristics measured. A split plot experiment in a randomized blocks design with three replications was used. In relation to plant growth and yield, plants grown on red mulch showed the best growth and yield overall compared to blue, gray, black, and yellow colored mulches, The incidence of the cucumber beetles was highest in the yellow colored mulch. The `Turbo' variety had the highest fruit number in almost all of the colors of mulch compared to the open pollinated `Marketmore'. It is suggested that the differential growth and development of cucumbers was influenced by the rhizosphere temperature as well as the light spectrum reflected from the plastic. The response of the beetles to the mulch was mainly attributed to the different wavelengths reflected from the various mulches.
Alternative Production Practices for Pecan
Authors: Smith Michael W.
Published: February 2019

Several new management tools and management practices are being developed for pecan. Major insect pests of pecan are pecan nut casebearer, hickory shuckworm, and pecan weevil. Sex pheromone attractants are being developed for each of these pests that improve monitoring. Also, a pecan weevil trap (Tedder's trap) was introduced recently that is more sensitive to weevil emergence than the previous trap. New models that predict critical periods for pecan scab infection are being tested. Certain legume ground covers are being tested to increase beneficial arthropods in the orchard for aphid control, and to supply N. Mulches are being investigated as an alternative to herbicide management for young trees. A mechanical fruit thinning method has been developed that increases fruit quality and reduces alternate bearing as well as stress-related disorders.
Health Functionality in Grapes and Wine
Authors: Morris Justin R.
Published: February 2019

The moderate consumption of red wine, grapes, raisins, and grape juice has a demonstrably positive effect on human health. Scientifically conducted surveys have shown that the effects of moderate intake of red wine reduces circulatory disease. Legislative efforts on labeling red wine to show the scientific evidence of this statement are receiving favorable attention. The antioxidant resveratrol, present in the skins of the grape in any of its various forms, is believed to be the agent primarily responsible for the healthful benefits demonstrated. It has been shown to affect lipid metabolism in higher mammals. Studies of resveratrol content in a variety of wine grapes are being performed at the Univ. of Arkansas, as well as at other institutions. Red wine (in contrast to white wine and other alcoholic beverages) reduces clotting ability and increases levels of high-density lipoproteins (“good” cholesterol), which diminishes the risk of coronary problems. Grape skin extract, red wines, and red juice appear to enhance the ability of blood vessels to resist vasoconstriction and to contribute to antithrombotic activity. In laboratory tests, several known antioxidants in wine out-performed vitamin E, the current best-known dietary antioxidant.
In Vitro Selection and in Vitro Screening for Disease Resistance in Fruit Trees
Authors: Hammerschlag Freddi A. , Hashmi Ghazala , Huettel Robin , Werner Dennis , Ritchie David
Published: February 2019

One approach for obtaining useful genetic variation is to select for somaclonal variants generated by tissue culture techniques. Increased levels of resistance to bacterial leaf spot (Xanthomonas campestris pv. pruni) have been observed in toxin-selected and unselected peach regenerants in vitro, in the greenhouse and under field conditions. Peach regenerants have also demonstrated increased levels of bacterial canker (Pseudomonas syringae pv. syringae) and root-knot nematode (Meloidogyne incognita) resistance. Random amplified polymorphic DNA (RAPD) primers have been used to study genetic variation at the DNA level among the somaclonal variants. Sixty RAPD primers (10-mers) were screened and 10 proved useful as markers to detect polymorphisms, thus establishing a genetic basis for somaclonal variation. These studies demonstrate the feasibility of using tissue culture techniques to generate fruit trees with increased levels of disease resistance.
Enhancement of Horticultural Crops for Improved Health
Authors: Munger Henry M.
Published: February 2019

Fruits and vegetables are being recommended more strongly than ever for improving human health, but, in some parts of the world, supplies are inadequate and, even when supplies are abundant, some segments of the population eat far less then recommended amounts. This divergence suggests that careful analysis and multiple approaches are needed to maximize the benefits of horticultural crops to human health. Information about the specific health benefits of certain crops and the value of diversity in the diet to get benefits not yet understood may stimulate increased usage. An attractive, appetizing, and economical supply seems essential, and may require efforts ranging from breeding for resistance, flavor, appearance, and holdability, through production and harvesting methods, to postharvest handling and processing.
RECYCLED NEWSPAPER AS A LANDSCAPE MULCH
Authors: Smith D. R. , Gilliam C. H. , Edwards J. H.
Published: February 2019

Two studies were conducted to evaluate recycled newspaper mulch for landscape plantings. In the first study, two paper products (pellets and crumble) were tested at three depths. Application of either 25 or 50 mm provided excellent control of prostrate spurge. Of the four annuals grown, ageratum exhibited severe stunting of roots and shoots. In the second study, three annual species were mulched with the two recycled paper products applied at 25 mm each and adjusted with P at 0, 3.75, or 7.5 ppm to bind excess Al. When no P was added, ageratum growth was about half that of the control plants. Addition of P at either rate resulted in similar growth compared to control plants. Marigold and geranium were less affected by recycled paper mulch; however, when P was added growth was always similar to nonmulched control plants.
SUMMER AND WINTER COVER CROPS IN A VEGETABLE ROTATION SYSTEM
Authors: Sanders D.C. , Gilsanz J.C. , Snerry W.J. , Hoyt G.D.
Published: February 2019

A 3-year study of cover crops (rye + crimson clover or sudex) and vegetable rotation systems was conducted using a Norfolk sandy loam soil. Cash crops were planted on all plots each spring, and in the fall, crops were snap beans/squash, sudex, or fallow. Late incorporation of cover crops depleted soil water content, resulting in a need for irrigation before spring plantings. Sudex residue had a high C: N ratio, delaying the total mineralization of N. Potato yields were not affected by rotation treatments. Cover crops improved snap bean emergence and yield. Snap beans had a differential uptake of Fe, Al, and B with cover crops. Tomato growth and yield were reduced with winter cover crops. Fall squash yield was not influenced by rotations.
HIGH-DENSITY APPLE ORCHARD MANAGEMENT TECHNIQUES EVALUATED FOR THE SOUTHEAST—YEAR 5
Authors: Parker Michael L. , Young Eric
Published: February 2019

Managing vegetative growth in higher density apple systems in the Southeast can be difficult due to the longer growing season. This study was initiated in 1990 to evaluate leader management techniques that have commercial potential for high-density systems in the Southeast. `Spur Galagored', `Jonagored', and `Red Fuji' apples on Mark root-stock were planted in the four major apple production regions of western North Carolina. The three leader management techniques evaluated were weak leader renewal, banding of the leader during the growing season (snaked leader), and leader heading with partial terminal leaf removal (H + PTLR) every 25 cm of leader growth. In the third year, branching was greatest for the snaked leader. In the fifth year, no differences in trunk cross-sectional area were detected between the leader management techniques. However, yields were significantly greater for trees managed with the snaked leader. Trees with the snaked leader yielded 44 kg/tree compared to 35 and 34 kg/tree for the H + PTLR and weak leader renewal, respectively. This illustrates that leader management techniques that use pruning or vegetation removal reduce the early production required of profitable high-density systems.
EARLY PERFORMANCE OF THE NC-140 APPLE CULTIVAR/ROOTSTOCK TRIAL: GROWTH AND YIELD, 1990–1995
Authors: Rom Curt R. , Allen R. Andy
Published: February 2019

`Empire', `Smoothee', `Jonagold', and `Rome Beauty' apple cultivars (CV) on five size-controlling rootstocks, Bud.9, M.9 EMLA, M.26 EMLA, Mark, and Ott.3, were planted in Fayetteville, Ark., in 1990 as a complete block design with six replications. Although interactions for several growth variables were observed in 1990–93, there were no cultivar–rootstock interactions in 1994, 1995, or for cumulative yield. After six seasons' growth, CV did not significantly affect any growth variable. Trees on M.26 and M.9 were the largest, while trees on Mark were significantly smaller for both tree height and TCA; trees on Ott.3 and Bud.9 were intermediate. `Smoothee' had the greatest cumulative yield, while both `Jonagold' and `Rome Beauty' had significantly less; `Empire' yield was intermediate. Trees on Ott.3 and M.26 had larger cumulative yields than other stocks, which were all similar. Trees on Mark had the greatest yield/TCA, while M.9 and M.26 had the least yield/TCA; Ott.3 and B.9 were intermediate. Trees on Mark had very high levels of foliar Mn and exhibited symptoms of Mn-induced internal bark necrosis.
FURTHER RESEARCH ON NITROGEN FERTIGATION OF PECANS
Authors: Worley Ray E. , Mullinix Ben G.
Published: February 2019

After 10 years, application of 112 kg N/ha, divided into four annual applications and applied through the drip irrigation system (fertigated), provided nut yield and quality as good as 224 kg·ha–1 all broadcast or 1/2 fertigated and 1/2 broadcast. Leaf N was well above the 2.50% deficiency threshold. Treatment rates were halved for six additional years with no detrimental effects on yield and quality from fertigation. All treatments still provided leaf N well above the deficiency threshold. After 16 years of N fertigation there appears to be no serious reduction of pH or flushing of other nutrients from the wetted zone of the emitter. Leaf and soil analysis indicate a loss of Ca and Mg in the area away from the emitter when N was broadcast. Soil pH and nutrients were lower in the wetted zone of the emitter than in the area not wet by the emitter, and soil pH, K, and Mg were reduced in the 15- to 30-cm layer with fertigation. Leaf nutrient concentrations reflected the cation concentrations in the nonwetted area. Broadcast N was from NH4NO3 and fertigated N was from URAN (16% N from NH4NO3 and 16% N from urea).
TRIFLURALIN FOR WEED CONTROL IN CORIANDER, DILL, AND DANDELION
Authors: Smart J.R. , Makus D.J. , Coleman R.J.
Published: February 2019

Field studies were conducted to determine the efficiency and crop safety of trifluralin [2,6-dinitro-N, N-dipropyl-4(trifluoromethyl) benzenamine] in coriander (Coriandrum sativum L.), dill (Anethum graveolens L.), and dandelion greens (Taraxacum officinale Weber) when applied preplant-incorporated at 0.56 and 0.84 kg a.i./ha. Visual injury evaluations, crop fresh and dry weight at maturity, and leaf area were used to determine adverse effects of trifluralin on each crop when compared to an untreated control. Dandelion greens had a 47% and 49% reduction in leaf area when treated with trifluralin at 0.56 and 0.84 kg a.i./ha when compared to the untreated weed-free dandelion treatment. Coriander and dill showed no visual crop phytotoxicity and no adverse effects on crop growth, fresh and dry weight yield, or leaf area when treated with trifluralin. Trifluralin, when used in combination with early season mechanical cultivation, can provide selective weed control of many of the most common winter annual weeds in south Texas while exhibiting a high level of crop tolerance for coriander and dill.
Root and Stem Growth Patterns of Young `Mauritius' Lychee Trees
Authors: Marler Thomas E. , Willis Leah E.
Published: February 2019

`Mauritius' lychee (Litchi chinensis Sonn.) trees were planted in root observation chambers in July 1990 to determine the pattern of root and stem extension growth during 12 months. Root and stem lengths were measured at intervals ranging from 7 to 18 days from Aug. 1990 until Aug. 1991. During each period of active canopy growth, up to six stem tips were tagged and measured. Root growth was determined by measuring tracings of the extension of each root in a visible plane of the glass wall of the observation chambers. Stem growth was cyclic, with distinct periods of rapid extension followed by periods with no extension. In contrast, root growth was fairly continuous with only three periods of no visible root extension. Mean absolute extension rates were higher for stems than for roots. There were no consistent relationships between the timing of root and stem extension growth.
Responses of Zinnia angustifolia × Z. violacea Backcross Hybrids to Three Pathogens
Authors: Boyle Thomas H. , Wick Robert L.
Published: February 2019

True-breeding lines of Zinnia marylandica Spooner, Stimart & Boyle [allotetraploids of Z. angustifolia H.B.K. and Z. violacea Cav. (2n = 4x = 46)] were backcrossed with autotetraploid Z. angustifolia (2n = 4x = 44) and Z. violacea (2n = 4x = 48). Seed-generated, backcross (BC1) families were screened for resistance to alternaria blight (Alternaria zinniae Pape), bacterial leaf and flower spot [Xanthomonas campestris pv. zinniae (Hopkins and Dowson) Dye], and powdery mildew (Erysiphe cichoracearum DC. ex Merat). All BC1 families exhibited high levels of resistance to alternaria blight and powdery mildew. BC1 families derived from crossing Z. marylandica with autotetraploid Z. angustifolia were highly resistant to bacterial leaf and flower spot, whereas BC1 families derived from crossing Z. marylandica with autotetraploid Z. violacea were susceptible to this disease. Our results suggest that one Z. angustifolia genome in BC1 allotetraploids is sufficient to confer resistance to A. zinniae and E. cichoracearum, but at least two Z. angustifolia genomes are required in BC1 allotetraploids to provide resistance to X. campestris pv. zinniae.
Micropropagation of Agarita (Berberis trifoliata Moric.)
Authors: Molinar Francisco , Mackay Wayne A. , Wall Marisa M. , Cardenas Manuel
Published: February 2019

Experiments were conducted to develop a clonal propagation system for agarita (Berberis trifoliata Moric.). Actively growing agarita shoots were collected from a mature plant at the Texas A&M Univ. Research and Extension Center in El Paso and successfully established on a basal medium consisting of woody plant medium (WPM) salts and Murashige and Skoog vitamins, sucrose at 30 g·L–1, and 0.8% Phytagar supplemented with 11.1 μm BA. Cytokinins (benzyladenine, kinetin, and thidiazuron), subculture period, and age of cultures were tested. The optimal shoot proliferation conditions were WPM basal medium supplemented with 5.5 μm BA and a subculture period of 4 weeks. Culture age did not affect shoot proliferation but did affect rooting. Preliminary experiments with 1.0 μm NAA resulted in nearly 100% rooting of microshoots <6 months old. Shoots from 21-month-old cultures had to be placed on a cytokinin-free medium before successful rooting. On basal medium supplemented with NAA (5.4 μm), 68% of the microshoots rooted with an average of 1.2 secondary roots per microshoot. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); 1-naphthaleneacetic acid (NAA); N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (thidiazuron or TDZ); 6-furfurlaminopurine (kinetin).
WATER USE BY THREE LANDSCAPE TREES UNDER LIMITING CONDITIONS
Authors: Khoury Ramzy , Tipton Jimmy L.
Published: February 2019

Evergreen elm (Ulmus parvifolia), southern live oak (Quercus virginiana), and South American mesquite (Prosopis alba) were irrigated at 75%, 50%, and 33% of reference evapotranspiration for 2 years in Phoenix, Ariz. Each tree was irrigated with twenty-nine 3.8-L·h–1 drip emitters to a depth of 90 cm. Initial trunk diameters were about 4 cm. Water use was monitored by heat balance sap flow gauges and related to canopy volume, projected canopy area, and total leaf area. Oak used more water than elm, and elm more than mesquite under all irrigation regimes. Irrigation regimes had a greater effect on oak and elm water use than on mesquite, but all trees maintained an acceptable canopy regardless of treatment.
Harvest Time and Nitrogen Source Influence In Vitro Growth of Apical Buds from Fraser Fir Seedlings
Authors: Bergmann Ben A. , Sun Ying-Hsuan , Stomp Anne-Marie
Published: February 2019

Information was obtained concerning appropriate bud harvest time and nitrogen source to be used in the tissue culture of Fraser fir [Abies fraseri (Pursh) Poir] apical buds from 2-year-old seedlings. April was the preferred time to harvest buds for culture, as summer buds had a high contamination frequency, and fall and winter buds did not develop well. Shoot elongation of buds collected in April (1.6 cm) was more than twice that of buds collected in February (0.7 cm) after 100 days in culture; during the same period, shoot fresh mass increased 5-fold (0.21 g in April, 0.04 g in February). Inclusion of a nitrate source reduced the frequency of bud browning, and glutamine was superior to ammonium as a source of reduced nitrogen. Litvay's basal medium containing 10 mm glutamine and 10 mm nitrate was the best nitrogen source combination tested when considering bud browning frequency and shoot fresh mass and length after 100 days in culture.
Inhibitory Activity of Corn Gluten Hydrolysate on Monocotyledonous and Dicotyledonous Species
Authors: Liu Dianna L. , Christians Nick E.
Published: February 2019

Corn gluten hydrolysate (CGH) was evaluated in the greenhouse for its herbicidal activity on 19 selected monocotyledonous and dicotyledonous species. Treatments included CGH at 0, 1, 2, 4, and 8 g·dm-2. Plant susceptibility was based on plant survival, shoot length, and root length. The germination and growth of all species were inhibited by the application of CGH at all rates. Black medic (Medicago lupulina L.), buckhorn plaintain (Plantago lanceolata L.), creeping bentgrass (Agrostis palustris Huds.), purslane (Portulaca oleracea L.), and redroot pigweed (Amaranthus retroflexus L.) were the most susceptible species, exhibiting more than 70% reduction in root length, 60% reduction in plant survival, and 52% reduction in shoot length with CGH at 1 g·dm-2. Common lambsquarters (Chenopodium album L.), curly dock (Rumex crispus L.), dandelion (Taraxacum officinale Weber), giant foxtail (Setaria faberi Herrm.), large crabgrass [Digitaria sanguinalis (L.) Scop.], and yellow foxtail [Setaria lutescens (Weigel) Hubb.] exhibited more than 50% reduction in root length and plant survival at 1 g·dm-2. Annual bluegrass (Poa annua L.), barnyardgrass [Echinochloa crusgali (L.) Beauv.], green foxtail [Setaria viridis (L.) Beauv.], orchardgrass (Dactylis glomerata L.), perennial ryegrass (Lolium perenne L.), quackgrass [Agropyron repens (L.) Beauv.], and velvetleaf (Abutilon theophrasti Medic.) survivial was reduced by 60% at 2 g·dm-2. Annual ryegrass (Lolium multiflorum Lam.) was the least susceptible species.
Evaluation of Poinsettia Cultivars for Susceptibility to Powdery Mildew
Authors: Celio G.J. , Hausbeck M.K.
Published: February 2019

Powdery mildew (Oidium spp. Link) on poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch) growing in commercial greenhouses was first observed in the United States in 1990. Susceptibility of poinsettia cultivars (`Freedom Red', `Hot Pink', `Jingle Bells 3', `Pink Peppermint', `Red Sails', `Supjibi Red', `Topwhite', `V-14 Glory', `V-14 Pink', `V-14 White', `V-17 Angelika White') to powdery mildew was investigated using 8- to 10-week-old poinsettias with mature bracts. Area under the incidence of disease progress curve was used to express the incidence of bracts infected over 31 d after inoculation. Three cultivars with red bracts (`Freedom Red', `Supjibi Red', `Red Sails') had significantly more infection than the other cultivars in both experiments, while one cultivar with white bracts (`V-17 Angelika White') had significantly less infection.
Management Alternatives for Purple and Yellow Nutsedge (Cyperus rotundus and C. esculentus)
Authors: McGiffen Milton E. , Cudney David W. , Obguchiekwe Edmond J. , Baameur Aziz , Kallenbach Robert L.
Published: February 2019

Yellow and purple nutsedge are problem perennials that resist common control measures. High temperatures, irrigation, and relatively non-competitive crops combine to greatly increase the severity of nutsedge infestations in the Southwest. We compared the growth and susceptibility of purple and yellow nutsedge to chemical and cultural control measures at several locations in southern California. When not controlled, low initial populations of either species led to heavy infestations later in the season. Purple nutsedge was far more prolific in both tuber production and above-ground growth. Summer rotations that included crops with dense canopies severly decreased nutsedge shoot and tuber growth. Cool-season crops planted into heavy nutsedge infestations in the fall are generally unaffected because nutsedge infestations in the fall are generally unaffected because nutsedge soon enters dormancy and ceases growth. Solarization, or pasteurization of the upper soil layers, was effective in decreasing tuber formation. Tillage effectively spread local infestations over larger areas.
Effect of Purple Nutsedge (Cyperus rotundus) Population Densities on the Yield of Eggplant (Solanum melongena)
Authors: Morales-Payan J.P. , Stall W.M.
Published: February 2019

Field experiments were conducted in Santo Domingo, Dominican Republic, to determine the effect of increasing population densities of purple nutsedge (Cyperus rotundus) on the yield of eggplant (Solanum melongena). Purple nutsedge populations were established by transplanting viable tubers on 1-m-wide soil beds previously fumigated to suppress volunteer weeds. Nutsedge densities were 0, 50, 100, 150, and 200 plants (tubers) per m2. `Jira' eggplants and purple nutsedge were transplanted the same day and were allowed to interfere season-long. Purple nutsedge initial population densities of up to 100 plants per m2 did not significantly affect the fruit yield of `Jira' eggplants. However, nutsedge densities between 100 and 200 plants per m2 had a significant impact on eggplant yield, causing a linear decline in fruit yield as purple nutsedge density increased. Eggplant fruit yield loss was 22.3% at the density of 200 nutsedge plants per m2.
Changes in Sugars and Volatiles of Ripening Erect Blackberry Fruit
Authors: Perkins-Veazie P. , Collins J.K. , Baldwin E. , Takeda Fumi
Published: February 2019

Erect-fruited blackberries are often described as having a wild blackberry flavor. Flavor can be greatly affected by sugar and volatile composition, neither of which is known for erect-fruited blackberries. This study was done to characterize changes in sugar and volatile composition in ripening blackberries. Blackberries of `Navaho', `Arapaho', `Shawnee', and `Choctaw' were harvested at red, mottled, shiny, and dull black ripeness stages. Sucrose was found in small amounts (4% to 15%) in all stages of ripeness in all cultivars. Total sugars increased from ≈20–30 to 60–80 mg/g dry weight as fruit ripened from red to dull black. Fructose and glucose maintained a constant 1:1 ratio with ripeness stage and cultivar. Three of the four cultivars had a linear increase in total sugars with ripening; total sugars increased 4% to 40% as fruit ripened from shiny to dull black. Twenty to 25 volatile peaks were found by headspace gas chromatography in ripening blackberries. Six volatiles, tentatively identified as α-pinene, eugenol, limonene, p-cymene, α-terpinol, and gernaylacetone, appeared in all cultivars, but only in ripe (shiny and dull black) fruit. Few volatile peaks were observed in red (unripe) fruit. Data indicate that blackberries continue to increase in sugars in the latter stages of ripeness and that volatiles unique to ripe blackberries are produced during this period.
Effects of Heat Treatment on Postharvest Quality of Mango Fruits
Authors: Zambrano Judith , Materano Willian
Published: February 2019

Mango fruits (Mangifera indica L.) were harvested at the preclimacteric stage. Fruits were immersed in 38, 42, 46, 50, and 54°C heated water for 30, 60, and 45 min prior to storage at 5°C for 2, 4, or 6 weeks in carton boxes. After storage, they were kept at 20°C. Fruits were evaluated for pulp color, total soluble solids, titrable acidity, ß-carotene content, reducing sugars and visible symptoms of chilling injury. Heated water had no significant effect on pulp color parameters (lightness, hue, and chroma). Soluble solids concentration, ß-carotene content and reducing sugars were higher in heated than in nonheated fruit after ripening. The chilling index was three-fold lower in treated than nontreated fruit. During storage and after removal at 20°C, hot-water-treated fruits ripened faster than nontreated fruits. Results of this study indicate that mango tolerance to chilling temperatures may increase after prestorage heat treatments.
Consumer Acceptance and Quality Characteristics of Disease-resistant Cultivars
Authors: Work T.M. , Work R.W. , Bushway A.A. , Schupp J.R.
Published: February 2019

Increased consumer awareness of pesticide usage in fruit production and demand for reduced pesticide residue on produce are major incentives to investigate the integration of disease-resistant apple cultivars into commercial fruit production. Appearance, flavor, and texture are key attributes in determining consumer acceptance of these new cultivars. The objectives of this study were to examine the physical, chemical, and sensory characteristics of five DRCs, `Liberty', `McShay', `NY 75414-1', `NY 74828-12', and `NY 65707-19', at harvest and following commercial storage. Consumer panels were asked to indicate their opinion of appearance, flavor, and overall attributes using a 9-point hedonic scale. Firmness, sweetness, and tartness were measured using a 5-point “just right” scale. Sugars, Hunter color, pH, titratable acidity, texture, Brix, and browning were determined. Statistical analysis of the parametric and nonparametric data were performed using SAS. Significant differences (P < 0.05) were seen in titratable acidity, Brix, Hunter color, and texture. `Liberty' and `NY 65707-19' received significantly (P < 0.05) higher liking scores for overall appearance. Firmness, sweetness, and tartness liking scores decreased over storage. However, `Liberty' and `NY 75414-1' maintained acceptable scores for these attributes. `NY 74828-12' was found significantly lower in degree of browning. Based upon the performance of these cultivars, `NY 75414-1' and `Liberty' have the greatest potential for fresh-market consumer acceptability and `NY 74828-12” may serve as a good processing cultivar due to reduced browning.