bluuebunny/crossref_metadata_2025 huggingface dataset:
Fruit Yield, Size, and Color Responses of Two Greenhouse Cucumber Types to Nitrogen Fertilization in Perlite Soilless Culture
Authors: Jasso-Chaverria C. , Hochmuth G.J. , Hochmuth R.C. , Sargent S.A.
Published: December 2018

Two greenhouse cucumber (Cucumis sativus) cultivars with differing fruit types [European (`Bologna') and Beit-alpha (`Sarig')] were grown during two seasons in a perlite medium in black plastic nursery containers in a passively ventilated greenhouse in northern Florida to evaluate fruiting responses to nitrogen (N) fertilization over the range of 75 to 375 mg·L–1. Fruit production, consisting mostly of fancy fruits, increased quadratically with N concentration in the nutrient solution, leveling off above 225 mg·L–1 for both cucumber cultivars. Fruit length and diameter were not affected by N concentration in the nutrient solution. Leaf N concentration, averaged over three sampling dates, increased linearly with N concentration in the nutrient solution from 46 g·kg–1 with 75 mg·L–1 N to 50 g·kg–1 with 375 mg·L–1 N. Fruit firmness decreased with increasing N concentration and there was little difference in firmness between the two cultivars. Firmness was similar across three measurement dates during the spring harvest season, but increased during the season in the fall. Fruit color responses to N concentration were dependent on the specific combination of experiment, sampling date, and cultivar. For most combinations of experiment, sampling date, and cultivar, cucumber epidermal color was greener (higher hue angle) with increased N concentration. The color was darkest (lowest L* value) and most intense (highest chroma value) with intermediate to higher N concentrations.
Field Comparison of Tensiometer and Granular Matrix Sensor Automatic Drip Irrigation on Tomato
Authors: Muñoz-Carpena Rafael , Li Yuncong C. , Klassen Waldemar , Dukes Michael D.
Published: December 2018

A low-volume/high frequency (LVHF) soil moisture-based drip irrigation system was tested on a shallow sandy soil at a commercial tomato (Lycopersicon esculentum) farm in southern Florida. Six LVHF irrigation treatments were compared with the standard commercial practice on the farm (control), where a portable pump was used for manual drip irrigation twice each week. In the six LVHF treatments the system was continuously pressurized by means of an electrical pump and a pressure tank, and controlled by an irrigation timer set to irrigate a maximum of five times per day with the irrigation time (i.e., volume) set according to historical evapotranspiration (ET) demands in the area. Two treatments were based on timer schedules, one to supply 100% of the maximum recommended crop water needs in the area based on historical ET (ET-100%), and the other to supply 150% of those needs (ET-150%). The other four treatments were created by interfacing two types of soil moisture sensors (switching tensiometers and granular matrix sensors with control modules) set at two moisture points (wet = 10 kPa, optimal = 15 kPa) in a closed control loop with the irrigation timer programmed at the ET-100% schedule. Results showed that the six LVHF treatments reduced water use while not significantly affecting tomato yields. Switching tensiometers at the 15 kPa set point performed the best (up to 73% reduction in water use when compared to the control, 50% with respect to ET-100%). The results show that water use below historical ET levels can be obtained without sacrificing yield by keeping the root zone moisture at controlled levels with the soil-moisture based system. Routine maintenance was critical for reliable operation of the switching tensiometers. Granular matrix sensor based irrigation behaved erratically, and did not improve water savings compared to ET-100%, indicating that this system was not effective under the conditions of the area due to the sensor's slow response to frequent wetting-rewetting cycles and characteristics of the interface.
Managing Nutsedge and Stunt Nematode in Pepper with Reduced Methyl Bromide plus Chloropicrin Rates under Virtually Impermeable Films
Authors: Santos Bielinski M. , Gilreath James P. , Motis Timothy N.
Published: December 2018

Two field trials were conducted to determine the effect of reduced methyl bromide plus chloropicrin (MBr + Pic 67:33 v/v) rates applied under two types of virtually impermeable films (VIF) on nutsedges (Cyperus spp.) and stunt nematode (Tylenchorhynchus spp.) control, and bell pepper (Capsicum annuum) crop yield. A split-plot design with six replications was established, with MBr + Pic rates in the main plots and mulch types as subplots. MBr + Pic rates were 0, 88, 175, and 350 lb/acre. Mulch types were low-density polyethylene (LDPE) mulch, Hytibar VIF, and Bromostop VIF. Results showed that there were no differences on weed and nematode control, and bell pepper fruit yield between the two types of VIF. Two exponential models characterized the nutsedge responses to MBr + Pic rates with LDPE mulch and VIF, with weed densities declining as MBr + Pic rates increased. Reducing MBr + Pic rates by one-half (175 lb/acre) under VIF provided similar nutsedge control as the full-rate (350 lb/acre) with LDPE mulch. Similar results were observed with stunt nematode, where the most effective control occurred with VIF. Bell pepper yield with LDPE mulch responded linearly to increased MBr + Pic rates. However, a logarithmic model described the response of pepper yields to the fumigant rates under VIF. The application rate of this fumigant could be effectively reduced to 25% of the commercial rate (350 lb/acre) under either VIF, without causing significant bell pepper yield losses.
Ground-penetrating Radar to Detect and Quantify Residual Root Fragments Following Peach Orchard Clearing
Authors: Cox K.D. , Scherm H. , Serman N.
Published: December 2018

Consecutive replanting of peach (Prunus persica) trees on the same orchard site can result in various replant problems and diseases, including armillaria root disease (Armillaria spp.), which develops upon contact between the roots of newly planted trees and infested residual root pieces in the soil. There is little information regarding the quantity of roots remaining in stone fruit orchards following tree removal and land clearing. We investigated the utility of ground-penetrating radar (GPR) to characterize reflector signals from peach root fragments in a controlled burial experiment and to quantify the amount of residual roots remaining after typical commercial orchard clearing. In the former experiment, roots ranging from 2.5 to 8.2 cm in diameter and buried at depths of 11 to 114 cm produced characteristic parabolic reflector signals in radar profiles. Image analysis of high-amplitude reflector area indicated significant linear relationships between signal strength (mean pixel intensity) and root diameter (r = -0.517; P = 0.0097; n = 24) or the combined effects of root diameter and burial depth, expressed though a depth × diameter term (r = -0.630; P = 0.0010; n = 24). In a peach orchard in which trees and roots had been removed following typical commercial practice (i.e., trees were pushed over, burned, and tree rows subsoiled), a GPR survey of six 4 × 8-m plots revealed that the majority of reflector signals indicative of root fragments were located in the upper 30 to 40 cm of soil. Based on ground-truth excavation of selected sites within plots, reflectors showing a strong parabolic curvature in the radar profiles corresponded to residual root fragments with 100% accuracy, whereas those displaying a high amplitude area represented roots in 86.1% of the cases. By contrast, reflectors with both poor curvature and low amplitude yielded roots for less than 10% of the excavated sites, whereas randomly selected sites lacking reflector signals were devoid of any roots or other subsurface objects. A high level of variability in the number of residual roots was inferred from the radar profiles of the six plots, indicating an aggregated distribution of root fragments throughout the field. The data further indicated that at least one residual root fragment would be present per cubic meter of soil, and that many of these fragments have diameters corresponding to good to excellent inoculum potential for armillaria root disease. Further GPR surveys involving different levels of land clearing, combined with long-term monitoring of armillaria root disease incidence in replanted trees, will be necessary to ascertain the disease threat posed by the levels of residual root biomass observed in this study.
Production of Commercially Valuable Sized Fruit as a Function of Navel Orange Yield
Authors: Kallsen Craig E.
Published: December 2018

The relationship between the number of commercially valuable sized fruit produced per unit land area vs. total number of fruit produced per unit land area for mature navel orange (Citrus sinensis) has not been documented. Knowing this relationship, referred to as the commercial fruit production function (CFPF) within this paper, may aid growers in making fruit thinning and tree pruning decisions and researchers in evaluating the interaction of fruit yield and size in response to fruit thinning, tree pruning, variety selection and tree spacing experimentation. For midseason navel oranges in the southern San Joaquin Valley of California, a reliable CFPF for total annual fruit production ranging from 14,000 to 130,000 fruit/acre was found to exist over multiple seasons in three orchards. The CFPF for two early maturing navel orange varieties was not significantly different with respect to slope or intercept from the CFPF for midseason varieties over the range of 12,000 to 63,000 fruit/acre, but became unreliable when fruit number exceeded 63,000 fruit/acre.
Evaluation of Radio Frequency–Hot Water Treatments for Postharvest Control of Codling Moth in `Bing' Sweet Cherries
Authors: Hansen J.D. , Heidt M.L. , Watkins M.A. , Drake S.R. , Tang J. , Wang S.
Published: December 2018

Quarantine regulations require domestic sweet cherries (Prunus avium) exported to Japan to be treated to control codling moth [Cydia pomonella (Lepidoptera: Tortricidae)]. The current procedure, methyl bromide fumigation, may be discontinued because of health, safety, and environmental concerns. To examine a potential alternative method, `Bing' sweet cherries were each infested with a codling moth larva, submerged in a 38 °C water bath for 6 minutes pretreatment, then exposed to various temperatures generated by radio frequency and held at that temperature for different times: 50 °C for 6 minutes, 51.6 °C for 4 minutes, 53.3 °C for 0.5 minutes, and 54.4 °C for 0.5 minutes. Insect mortality was evaluated 24 hours after treatment and fruit quality was evaluated after treatment and after 7 and 14 days of storage at 1 °C. No larvae survived at the 50 and 51.6 °C treatments. Fruit color of non-infested cherries was darkened as temperature increased. Stem color was severely impacted after 7 days of storage, even in a warm water bath of 38 °C for 6 minutes, as was fruit firmness at the same treatment. Fruit quality loss increased after 14 days of storage, compared to after 7 days of storage. The amount of pitting and bruising of cherries increased with temperature and again this increase was more evident after 14 days of storage.
Evaluation of Four Lamp Types for the Production of Tomato Plants in Controlled Environments
Authors: Zheng Youbin , Zhang Ping , Dixon Mike
Published: December 2018

To evaluate the performance of four newly developed high-intensity-discharge lamp types on plant growth and production, tomato (Lycopersicon esculentum cv. Tradiro F1) plants were grown indoors under 100% artificial lighting for 17 weeks. The four lamp types were: high-pressure sodium high output [HPS(HO)], high-pressure sodium standard [HPS(STD)], metal halide warm deluxe [MH(WDX)] and metal halide cool deluxe [MH(CDX)]. All the lamps tested were 1000 W. HPS(HO) had the highest electrical energy use efficiency (EUE) (0.98 μmol·m–2·s–1·W–1 at 40 cm directly under the lamp); HPS(STD), MH(WDX) and MH(CDX) had 93%, 72% and 61% of the EUE of the HPS(HO), respectively. The photosynthetically active radiation (PAR) outputs of different lamp types had the following order: HPS(HO) > HPS(STD) > MH(WDX) > MH(CDX). The percentage red of PAR of the four tested lamp types had the same order as above, but the percentage blue of PAR of these lamp types had exactly the opposite order. As a result, plants growing under the two HPS lamp types were taller and flowered and fruited earlier than plants under the two MH lamp types. Chlorophyll content index was generally greater in leaves under MH lamps than in leaves under HPS lamps. We recommend that the HPS lamp be used for flowering and fruiting crops and the MH lamp would be better used for foliar and compact crops.
Components, Utilization, and Support of Southern Turfgrass Research Units
Authors: Miller Grady L.
Published: December 2018

A survey of selected land-grant universities was conducted to gather information related to design and operation of their turfgrass research units. The objective of this survey was to help the University of Florida in planning a new research unit that will be constructed in 2004–05. The survey provided information related to turf area, building facilities, equipment, supplies, and maintenance. Type of monetary support, cost sharing, labor requirements, utilities, and capitol improvement outlays were documented. The number of support people and faculty with activities at the unit varied depending upon the location, with a mean of five research support people, two support staff, and seven faculty across all units. With the exception of fertilizers (50% donated vs. 50% purchased), most (>80%) of the chemicals, seed, and sod was donated to the units. About one-third of the monetary support for operating and general labor expenses for the units was from soft money and one-third from direct state support. Results from this survey provided ideas that could be used to design and staff a new turfgrass research unit or support for updating an existing unit. In addition, turfgrass industry representatives have an interest in the data since they provide a significant portion of the monetary support and supply of materials to turf research units.
PediTrack—An Adaptable Pedigree Tracking Program
Authors: Stafne Eric T. , Clark John R.
Published: December 2018

In a database system that allows for quick and accurate querying, PediTrack generates pedigrees in an easily understandable format. Other pedigree programs are available commercially, but are often expensive, specific to certain organisms, or unadaptable for specific programmatic use. PediTrack allows a personal computer (PC) user with Microsoft Access version 2000 or higher to use the simple program without charge. This software is widely available and easily adaptable to a variety of breeding program functions. PediTrack does not perform any calculations, so the initial program size is small (<2 megabytes). The program consists solely of the basic framework for housing pedigree information and reporting pedigrees based on those records.
Refractometer Measurements of Soluble Solid Concentration Do Not Reliably Predict Sugar Content in Sweet Corn
Authors: Hale Teri A. , Hassell Richard L. , Phillips Tyron
Published: December 2018

The refractometer has been proposed as a rapid, inexpensive technique for determining sugar levels in fresh sweet corn (Zea mays). High performance liquid chromatography (HPLC) analysis of sugars in three phenotypes (su, se, and sh2) of sweet corn harvested at three maturities indicated that sucrose content was highly correlated with the total sugars (R = 0.95). Sucrose and total sugar concentration were significantly different among all phenotypes. Soluble solids concentration (SSC) was high in su and se compared to the lower SSC of sh2. Early, mature, and late harvested samples differed in sucrose and total sugar content. Sugar concentration varied within phenotypes at each maturity level. Sh2 indicated no difference in sucrose and total sugars at early and mature harvests, but increased at late harvest. In contrast, sucrose and total sugar content decreased between early and mature harvests, then increased to highest levels at late harvest in se and su phenotypes. Overall, phenotype SSC increased significantly from early to late harvests, probably due to increased water-soluble polysaccharides in the su and se cultivars. Unlike other crops, a negative relationship was found in sweet corn between SSC and sucrose or total sugars, with an overall correlation of –0.51. This relationship was most affected by maturity, especially mature and late harvested sweet corn. Among phenotypes, sucrose, total sugar, and SSC were poorly correlated. Our results indicate that a refractometer should not be used to estimate total sugars or sucrose of sweet corn.
Edamame Production as Influenced by Seedling Emergence and Plant Population
Authors: Sánchez Elsa , Kelley Kathleen , Butler Lynn
Published: December 2018

Eight edamame (Glycine max) cultivars were evaluated in the field in 2002, 2003, and 2004 to determine suitability for growing in central Pennsylvania. Data collection included plant populations (percent stand), marketable and unmarketable yields and edamame pod and bean quality indicators. Plant populations varied by year and cultivar and were generally below 80%. The effect of temperature on seedling emergence, and therefore plant populations, was evaluated for four edamame cultivars by using growth chambers programmed with varying day/night temperature regimes. Seedling emergence varied by cultivar and was generally below 80% with two exceptions. When grown in a 70/60 °F day/night temperature regime, `Butterbeans', and `Early Hakucho' exceeded 80% seedling emergence. In the field trial, plant populations affected marketable yields. Pod and bean quality were dependent on cultivar. Results indicated that `Butterbeans', `Early Hakucho', `Green Legend', `Shironomai', `Butterbaby', and `Lucky Lion' appear promising for growing in Pennsylvania based on pod and bean quality. However, the issue of poor seedling emergence and plant populations presents a major constraint to commercial production and needs to be studied further.
Fire Flash: An Exotic Ornamental Foliage Plant
Authors: Chen Jianjun , McConnell Dennis B. , Henny Richard J. , Everitt Kelly , Caldwell Russell D.
Published: December 2018

Fire flash (Chlorophytum amaniense), a member of Liliaceae, is attracting considerable attention in the foliage plant industry as a new addition for interior plantscaping. Coral-colored petioles and midribs contrasting with dark green leaves make it a sought after specimen. Originally collected from rainforests of eastern Africa in 1902, it has remained largely obscure for a century. Recently, studies on fire flash's propagation, production, and interiorscape performance have been completed. This report presents relevant botanical information and the results of our 4-year evaluation of this plant. Fire flash can be propagated through seed, division, or tissue culture and produced as a potted foliage plant under light levels from 114 to 228 μmol·m–2·s–1 and temperatures from 18 to 32 °C. Finished plants after being placed in building interiors are able to maintain their aesthetic appearances under a light level as low as 8 μmol·m–2·s–1 for 8 months or longer.
Landscape Performance of Sun Coleus in Southern Mississippi
Authors: Coker Christine E. , Knight Patricia R. , Anderson John M.
Published: December 2018

Sun coleus (Solenostenum scutellarioides) are commonly used in the southern landscape. However, with the introduction of new cultivars, producers and consumers may be unaware of the selection and landscape performance of sun coleus. Sun coleus cultivars were trialed under landscape conditions at the South Mississippi Branch Station in Poplarville, Miss., in 2000 and 2001. The objective of this study was to evaluate sun coleus cultivars based on landscape performance criteria including flowering, durability, vigor, uniqueness, and insect and disease resistance. Cultivars performing well over both years included `Ducksfoot Red,' `Ducksfoot Tricolor', `Ducksfoot Yellow', `Sunflower Red', `Pineapple', Mardi Gras', and `Saturn'.
Application of an Automatic Control System of Photosynthetic Photon Flux Density for LED-Low Light Irradiation Storage of Green Plants
Authors: Fujiwara Kazuhiro , Sawada Toshinari , Kimura Yoshikatsu , Kurata Kenji
Published: December 2018

A light-emitting diode (LED)-low light irradiation (LLI) storage system was developed for suppressing the change in dry weight and maintaining the quality of green plants during long-term storage. In this system, the carbon dioxide (CO2) exchange rate was maintained at zero by automatically adjusting the photosynthetic photon flux density (PPFD) with a proportional-integralderivative (PID) controller. The voltage supplied to the LEDs was controlled by the difference between the inflow (400 μmol·mol-1) and outflow CO2 concentrations in the storage case. Grafted tomato (Lycopersicon esculentum; scion = `House Momotaro'; rootstock = `Anchor T') plug seedlings were stored at 10 °C for 35 days under four different LLI conditions as a system operating test: fixed red light irradiation at 2 μmol·m-2·s-1, PID-controlled red light irradiation with no blue light, and PID-controlled red light irradiation with blue light at 0.2 or 1.0 μmol·m-2·s-1. The results showed that the automatic PPFD control during LED-LLI helped suppress changes in dry weight during storage as expected. Furthermore, it was found that addition of a low percentage of blue light improved the morphological appearance of the seedlings and reduced the PPFD required to suppress the change in dry weight.
Effects of Low-dose Electron Beam Irradiation on Respiration, Microbiology, Color, and Texture of Fresh-cut Cantaloupe
Authors: Boynton B.B. , Sims C.A. , Balaban M.O. , Marshall M.R. , Welt B.A. , Brecht J.K.
Published: December 2018

Cantaloupes (Cucumis melo) in three separate trials were cut into 1-inch cubes and irradiated at 0, 0.25, 0.5, 0.75, 1.0, 1.25, or 1.5 kGy; 0, 0.1, 0.2, 0.3, 0.4, 0.5, or 0.7 kGy; and 0, 0.3, 0.6, or 0.9 kGy, respectively. They were then stored in air at 3 °C for up to 20 days, and respiration rate, measured as carbon dioxide (CO2) production, microbiological counts [total plate count (TPC) and yeast and molds], texture, and color were measured during storage. Respiration rates were initially higher in irradiated cantaloupe. After 8 days, respiration was similar between irradiated and control fruit. Irradiation moderated increases in respiration in a dose-dependent manner. Highest irradiation doses resulted in initial TPC reductions of 1.5 log compared to the non-irradiated controls, and also prevented the 2.5 to 3 log TPC increases seen in controls after 10 to 11 days of storage. Texture differed on day 1, when controls were most firm, but irradiation maintained greater firmness than controls after day 7. Irradiation of fresh-cut cantaloupe has potential for shelf life extension and for integration with modified atmosphere packaging systems.
An Innovative Vegetative Propagation System for Large-scale Production of Globe Artichoke Transplants. Part I. Propagation System Setup
Authors: Cardarelli Mariateresa , Rouphael Youssef , Saccardo Francesco , Colla Giuseppe
Published: December 2018

A research project was conducted at the University of Tuscia, Viterbo (central Italy), to set up a vegetative propagation system for producing diseasefree artichoke transplants (Cynara cardunculus var. scolymus) of the Romanesco type (cultivar C3). The system included the following steps: 1) micropropagated plantlets were grown in a soilless culture year-round in greenhouse conditions, starting at the end of August; 2) stock plants were periodically treated with a chemical growth regulator [6-benzylamino purine (BA)] and then cut back at the collar level to promote offshoot production; 3) offshoots were periodically harvested and cold stored; and 4) cuttings were rooted at the end of spring under conditions of high humidity in multi-pack trays so as to be ready for summer transplanting. Results showed that the foliar application of BA to the stock plants increased the offshoot number quadratically to 200 mg·L-1. The rooting percentages of cuttings and root growth were enhanced by raising the cutting weight class (30-45 g) and by the application of naphthaleneacetic acid (NAA) to the cutting root zone at a rate of 2000 mg·L-1. The percent rotten cuttings increased as the 2 °C cold-storage time increased from 30 to 150 days. Similarly, the percentage of rooting and root growth decreased approximately from 60 to 150 days.
Flower Color Preferences of Western Flower Thrips
Authors: Blumthal Meredith R. , Spomer L. Art , Warnock Daniel F. , Cloyd Raymond A.
Published: December 2018

Flower color preference of western flower thrips [WFT (Frankliniella occidentalis) (Thysanoptera: Thripidae)] was assessed by observing insect location after introduction into chambers containing four different colored flowers of each of three plant species: transvaal daisy (Gerbera jamesonii), matsumoto aster (Callistephus chinensis), and chrysanthemum (Dendranthema ×grandiflorum). Preference was based on the number of WFT adults found on each flower 72 hours after infestation. Significantly higher numbers of WFT were found on yellow transvaal daisy and yellow chrysanthemum. When these accessions were compared in a subsequent experiment, WFT displayed a significant greater preference for the yellow transvaal daisy. Visible and near infrared reflectance spectra of the flowers used in the study were measured to determine the presence of distinct spectral features that would account for the relative attractiveness of the flowers. Likewise, the reflectance spectra of three commercially available sticky cards (blue, yellow, and yellow with a grid pattern) that are used to trap or sample for WFT were compared to those of the flowers to determine any shared spectral features that would support observed WFT flower color preference. The observed similarity between the yellow transvaal daisy and yellow sticky card reflectance spectra supports the hypothesis that flower color contributes to attractiveness of WFT. In particular, the wavelengths corresponding to green-yellow (500 to 600 nm) seem to be responsible for attracting WFT. These findings also indicate that yellow sticky cards may be more appropriate in sampling for WFT than blue sticky cards. Although further research is needed, under the conditions of this study, yellow transvaal daisy appears to be a potentially useful trap crop for WFT.
Comparison of Flurprimidol to Ethephon, Paclobutrazol, and Uniconazole for Hyacinth Height Control
Authors: Krug Brian A. , Whipker Brian E. , McCall Ingram , Dole John M.
Published: December 2018

Preplant bulb soaks of flurprimidol, paclobutrazol, and uniconazole; foliar sprays of ethephon and flurprimidol; and substrate drenches of flurprimidol were compared for height control of `Anna Marie' hyacinths (Hyacinthus orientalis). Preplant bulb soak concentrations of flurprimidol and paclobutrazol were from 25 to 400 mg·L-1, and uniconazole from 5 to 80 mg·L-1. Height control was evaluated at anthesis and 11 days later under postharvest conditions. Ethephon (250 to 2000 mg·L-1) and flurprimidol (5 to 80 mg·L-1) foliar sprays were ineffective. Flurprimidol (0.25 to 4 mg/pot) drenches had no effect during forcing, but controlled postharvest height at concentrations ≥0.25 mg/pot a.i. with at least 4% shorter plants than the untreated control. Preplant bulb soaks resulted in height control with flurprimidol ≥25 mg·L-1, paclobutrazol ≥100 mg·L-1, and uniconazole ≥40 mg·L-1; having at least 9%, 6%, and 19%, respectively, shorter plants than the untreated control. Based on our results, flurprimidol preplant bulb soaks have a greater efficacy than either uniconazole or paclobutrazol. Preplant PGR soaks are a cost-effective method of controlling plant height of hyacinths because of the limited amount of chemical required to treat a large quantity of bulbs.
Effect of Cultivar and Site on Fruit Quality as Demonstrated by the NE-183 Regional Project on Apple Cultivars
Authors: Miller S.S. , McNew R.W. , Barritt B.H. , Berkett L. , Brown S.K. , Cline J.A. , Clements J.M. , Cowgill W.P. , Crassweller R.M. , Garcia M.E. , Greene D.W. , Greene G.M. , Hampson C.R. , Merwin I. , Miller D.D. , Moran R.E. , Rom C.R. , Roper T.R. , Schupp J.R. , Stover E.
Published: December 2018

Cultivar and planting site are two factors that often receive minimal attention, but can have a significant impact on the quality of apple (Malus ×domestica) produced. A regional project, NE-183 The Multidisciplinary Evaluation of New Apple Cultivars, was initiated in 1995 to systematically evaluate 20 newer apple cultivars on Malling.9 (M.9) rootstock across 19 sites in North America. This paper describes the effect of cultivar and site on fruit quality and sensory attributes at a number of the planting sites for the 1998 through 2000 growing seasons. Fruit quality attributes measured included fruit weight, length: diameter ratio, soluble solids concentration (SSC), titratable acidity (TA), flesh firmness, red overcolor, and russet. Fruit sensory characteristics rated included crispness, sweetness, and juiciness, based on a unipolar intensity scale (where 1 = least and 5 = most), and acidity, flavor, attractiveness, and desirability based on a bipolar hedonic scale (where 1 = dislike and 5 = like extremely). All fruit quality and sensory variables measured were affected by cultivar. The two-way interaction of cultivar and planting site was significant for all response variables except SSC, TA, russet, crispness, and sweetness ratings. The SSC: TA ratio was strongly correlated with sweetness and acidity sensory rating, but was weakly correlated with flavor rating. The results demonstrate that no one cultivar is ideally suited for all planting sites and no planting site is ideal for maximizing the quality of all apple cultivars.
Impact of Chloropicrin on Nutsedge Emergence through Polyethylene Mulch
Authors: Santos Bielinski M. , Gilreath James P. , Motis Timothy N.
Published: December 2018

Field trials were conducted from 1999 to 2003 to determine whether chloropicrin (Pic) stimulates nutsedge (Cyperus spp.) emergence through polyethylene mulch, and to examine at which Pic rate the stimulatory effect is maximized. Shank-injected Pic rates were 0, 50, 100, 150, 200, and 250 lb/acre. Application rates between 107 and 184 lb/acre of Pic stimulated nutsedge sprouting through polyethylene mulch by 60%, 400%, 58%, and 120% more than the nontreated control during four of the seasons. Rates above 250 lb/acre eliminated the stimulatory effect on nutsedge, reducing densities to the same levels as the nontreated control. The exact physiological mechanism of this stimulation is still unknown.
Visiting Outdoor Green Environments Positively Impacts Self-rated Health among Older People in Long-term Care
Authors: Rappe Erja , Kivelä Sirkka-Liisa , Rita Hannu
Published: December 2018

The restorative effects of nature in enhancing human well-being are well documented. However, the effects of exposure to a green environment on health in institutional settings have not been adequately studied. Our study describes the relationship between the reported frequency of visits to an outdoor green environment and self-rated health, including hindrances experienced during outdoor visits among older people living in a nursing home. Forty-five women assessed their health and answered a questionnaire containing the Nottingham Health Profile (NHP) during an interview. A strong positive association was established between the reported frequency of visiting outdoors and self-rated health even when taking into account health-related distresses measured using the NHP (B = 0.235, P < 0.01). The main hindrances related to outdoor visits were lack of assistance and uncomfortable weather conditions. The results suggest that it might be possible to promote the well-being of older individuals living in nursing homes by providing them with opportunities to visit outdoor green environments. By increasing the accessibility and attractiveness of the outdoor environment, the frequency of outdoor visits could increase, resulting in better perceived health. Implementation of environmental interventions that facilitate year-round outdoor visits are recommended.
Evaluation of Abscisic Acid Analogs as Holding Agents for Bedding Plant Seedlings
Authors: Sharma Nirmala , Waterer Doug R. , Abrams Suzanne R.
Published: December 2018

The marketing period of nursery-raised bedding plant seedlings is limited by the loss of aesthetic quality associated with undesirable growth and/or excess moisture loss during storage and handling. Long-lasting synthetic analogs of abscisic acid (ABA) (8′-methylene ABA methyl ester and 8′-acetylene ABA methyl ester) were evaluated for their potential use in controlling growth and extending the marketing period of seedlings of tomato (Lycopersicon esculentum), snapdragon (Antirrhinum majus), and nasturtium (Tropelaum majus). ABA analogs, applied as root-dips, slowed moisture use and reduced seedling growth in a dosage-dependent manner with no significant phytotoxic effects over the short term. The nature and duration of the responses of the three test crops to the ABA analog treatments were similar. ABA analogs were more effective at reducing moisture use by tomato seedlings than regular ABA and also had fewer negative effects on plant appearance. Before ABA analogs can be recommended for commercial-scale use, their impact on long-term performance needs to be determined, along with an evaluation of their cost and safety relative to other plant growth retardants.
Optimal Low-pressure Conditions for Long-term Storage of Fresh Commodities Kill Caribbean Fruit Fly Eggs and Larvae
Authors: Davenport Thomas L. , White Thomas L. , Burg Stanley P.
Published: December 2018

U.S. regulations prevent importation of fresh horticultural commodities that have not received an approved quarantine treatment assuring 99.999% (Probit 9) mortality of potentially invasive insect pests. Because imported mangoes (Mangifera indica) are likely to be infested by the caribbean fruit fly (Anastrepha suspensa) and other tropical fruit flies in the Americas, such as the mexican fruit fly (A. ludens), guava fruit fly (A. striata), inga fruit fly (A. distincta), south american fruit fly (A. fraterculus), sapote fruit fly (A. serpentina), and the west indian fruit fly (A. obliqua), they must be hot-water treated prior to shipment in order to satisfy quarantine requirement. Hot water treatment often damages the fruit, especially if it is not fully mature. Hypobaric [low pressure (LP)] intermodal shipping containers developed by the VacuFresh Corp. preserve fresh commodities, such as horticulturally mature mangoes, far longer than is possible using other technologies. We tested the ability of caribbean fruit fly eggs and larvae to survive simulated optimal hypobaric conditions for shipment of mangoes [15 and 20 mm mercury (Hg), ≥98% relative humidity, 13 °C (the lowest, safe nonchilling temperature)]. Caribbean fruit fly eggs or larvae were maintained on agar media, flushed with one air change per hour at the storage pressure, and shielded with Mylar to prevent radiant heat uptake and limit evaporative cooling. Nearly 98% of the eggs and larvae were killed within 1 week at 15 and 20 mm Hg in nine replicated experiments. All eggs were killed by 11 days with a predicted kill of 99.999% of the eggs by 9.4 days in 15 mm Hg and 10.6 days in 20 mm Hg LP (based on Probit 9 statistical analysis), whereas a substantial number of eggs survived to 14 days at atmospheric pressure (760 mm Hg). Shipment of fresh produce using this technology promises to provide quarantine control while preserving the freshness of fully mature tropical fruits and vegetables.
Children's Garden Consultants: A New Model of Engaging Youth to Inform Garden Design and Programming
Authors: Lekies Kristi S. , Eames-Sheavly Marcia , Wong Kimberly J. , Ceccarini Anne
Published: December 2018

This paper discusses a unique garden and youth-focused event in which a group of 4-H youth engaged in a “children's garden consultants” program. Over a 3-day period, seven teenaged youth were given the opportunity to actively research children's garden design and educational programming, and then present recommendations to an adult audience of children's garden experts and youth development specialists. Surveys, observations, and discussions with youth, adults in attendance, and program organizers indicated the event was highly valuable and worth repeating. It provided a new learning opportunity for youth, and it also gave adults new perspectives on gardens. The youth's ideas for improving children's gardens and suggestions for future programming are presented as well.
A Survey of Horticulture and Plant Science Graduate Programs and Faculty Salaries at North American Universities
Authors: Arnold Michael A. , Davis Tim D. , Reed David W.
Published: December 2018

A group of 53 institutions of higher education in the United States and Canada offering degrees in horticulture, or closely related plant science degrees, was surveyed to determine various characteristics associated with the degree programs offered, demographics of students and faculty, and selected procedures and practices associated with administration of these graduate programs. Total response rate was 94%, yielding 85% usable completed surveys. Very few programs (0-3 per degree type) were offered via distance education and on average only 4.1% to 4.5% of resident instruction program students participated in distance education courses. Domestic students averaged 64% to 75% of enrollment. Students were 69% to 73% white. Asian students were the predominant minority group at 12% to 16% of enrollment, followed by African Americans (3% to 8%) and Hispanics (1% to 4%). Most institutions provided out-of-state tuition waivers (75%), and often in-state-tuition waivers (61%), to those students on assistantships or fellowships. Typical commitments to students were 3 years for a PhD and 2 years for a master's degree program. Research assistantships were the dominant form of assistance at all institutions (38% to 53% of students), while teaching assistantships contributed significant secondary funding (7% to 13%). With the exception of mean maximum fellowships, mean maximum assistantships ($11,499-$13,999) at non-1862 Morrill Act universities (NMAU) averaged near the mean minimums ($13,042-$14,566) for the corresponding assistantship types at 1862 Morrill Act universities (MAU). Requirements for teaching experience ranged from 41% of PhD programs to 18% of non-thesis master's degree programs. Typical departments contained 29 faculty members, of which 44% were full professors, 27% associate professors, 19% assistant professors, 6% junior or senior lecturers, and 3% were in other classifications. Traditional 12-month appointments (65.9% of faculty) were predominant at MAU. With the exception of junior lecturer positions, mean salaries at MAU averaged $9125, $6869, $8325, and $28,505 more for professor, associate professor, assistant professor, and senior lecturer, respectively, than at NMAU. This study provides useful information for departments undergoing external review or revision of graduate programs.
Screening Spinach Cultivars for White Rust Resistance and Bolting
Authors: Goreta Smiljana , Leskovar Daniel I.
Published: December 2018

Areas with mild climate conditions are suitable for growing winter spinach (Spinacia oleracea L.). Successful production depends on choosing slow-bolting cultivars resistant to major diseases in each area. Field experiments with a total of 18 cultivars were conducted during 8 years in the Winter Garden region of Texas, an area known for its high white rust (Albugo occidentalis G.W. Wils) inoculum. Spinach cultivars differed widely in their resistance to both white rust and bolting, and the incidence of both traits was more severe as the season progressed. White rust infection increased linearly with average monthly minimal air temperature. Cultivars Fidalgo, Springfield, and Springer were slow bolting and are suitable for areas with no white rust incidence, while cvs. ASR-318, DMC 66-09, Fall Green, Samish, and San Juan were more white rust resistant.
Potato Leafhopper Control and Plastic Mulch Culture in Organic Potato Production
Authors: Maletta Martha , Henninger Melvin , Holmstrom Kristian
Published: December 2018

Control tactics for potato leafhopper (Empoasca fabae) in certified organic potato (Solanum tuberosum) production were evaluated in 2003 and 2004. The 2004 split plot trial also compared silver plastic mulch culture with bare ground culture. The trials were conducted at the Rutgers Snyder Research and Extension Farm's certified organic fields, and production practices conformed to the standards of the National Organic Program (NOP). `Superior' potato was grown both years. Potato leafhopper (PLH) controls evaluated were: kaolin, pyrethrin, pyrethrin plus kaolin (2003), pyrethrin with silicon dioxide (2004), and silver plastic mulch (2003). Pyrethrin, pyrethrin plus kaolin, and pyrethrin with silicon dioxide reduced PLH nymph counts and PLH damage (hopperburn) ratings compared with the untreated check (UTC). Kaolin did not reduce nymph counts or hopperburn ratings. In 2003, nymph counts and hopperburn ratings were higher in the mulch treatment than in the UTC, yet the mulch treatment produced higher yield than the UTC. In 2004, mulch culture increased total and marketable yield compared with bare ground culture when PLH was controlled. Nymph counts and hopperburn ratings were higher until mid-July in the mulch plots than bare ground plots with the UTC and kaolin treatments. Controlling PLH and using plastic mulch culture significantly increased organic potato yields and tuber size. Marketable yields from the UTC were less than the New Jersey average of 275 cwt/acre for conventionally grown potato: yield was 38% of average on bare ground and 68% of average on mulch in 2003; 33% of average on bare ground and 38% of average on mulch in 2004. Reducing hopperburn with pyrethrin on plants grown on mulch (2004) resulted in marketable yield that was 75% of the New Jersey average.
Effects of Pruning and Cluster Thinning on Yield and Fruit Composition of `Chambourcin' Grapevines
Authors: Kurtural S. Kaan , Dami Imed E. , Taylor Bradley H.
Published: December 2018

Response of yield components and fruit composition of `Chambourcin' (Vitis vinifera × V. rupestris) grapevines to three pruning levels of 15, 20, and 25 nodes retained for each pound of dormant prunings; and three cluster thinning levels of 1, 2, and 2+ clusters per shoot in 2002 and 1, 1.2, and 1.5 clusters per shoot in 2003 were measured at two vineyards in the lower midwestern United States. In both years of the study, there was very little interaction of pruning and cluster thinning. The proportion of non-count shoots increased within the canopy in response to increased pruning severity. Pruning weight means were lower in 2002 across all treatments compared to 2003. Pruning weights decreased with the increase in the number of clusters retained per vine. Pruning influenced yield only in 2003 when the proportion of count shoots decreased below 62% of the total, hence the relationship between number of shoots per vine and yield (R2 = 0.3452; P < 0.0003). In both years of the study, the increase in severity of cluster thinning resulted in yield reduction but an increase in the total soluble solids in juice. Yield compensation was achieved by an increase in cluster weight of 38%, and 25% in response to a reduction of 37%, and 23% in cluster numbers; which translated into a yield reduction of only 10% and 3%, at Vineyards 1 and 2, respectively. Balanced pruning to 15 to 20 nodes per 1 lb of prunings and cluster thinning to 1 to 1.2 clusters/shoot optimized yield (9.7 kg/vine, 13.4 t·ha-1) and fruit composition, and maintained vine size (≥0.3 kg·m-1 of row). These results provide valuable information for growers of `Chambourcin' grapevines in the lower midwestern U.S., as well as in other climates with long growing seasons.
Low-volume Sprays to Treat Fresh-sliced Apples with Anti-browning Solution
Authors: Toivonen Peter M.A. , Delaquis Pascal
Published: December 2018

Use of sprays to sanitize and treat apple (Malus ×domestica) slices helps to reduce the potential for cross-contamination that can occur when treatments are done in dip tanks. This research examined several factors that may affect the efficacy of spray treatments: 1) spray volume; 2) efficacy of spray application of anti-browning solution (ABS) compared with dipping; 3) effect of slice density during spraying; and 4) effect of the addition of an antimicrobial compound, vanillin, on microbiologically associated browning. Low-volume sprays (36-50 mL·kg-1 slices) of ABS gave maximal control of browning and this was equivalent to the control afforded by a 2-minute dip in the ABS. Spray application resulted in significant reduction in incidence and severity of microbiologically associated “secondary browning” as compared with dip application. However, if more than one layer of slices were present on the support mesh during the spray treatment, then secondary browning increased. This was attributed to potential cross-contamination between layers of apples in the spray treatment. Addition of vanillin into the ABS resulted in a 50% reduction of the incidence of “secondary browning.” Low-volume spray applications of ABS can be managed such that the microbiologically associated “secondary browning” is much lower than possible with dip application.
Fresh-market Carrot Yield and Quality Did Not Respond to Potassium Fertilization on a Sandy Soil Validated by Mehlich-1 Soil Test
Authors: Hochmuth George J. , Brecht Jeffrey K. , Bassett Mark J.
Published: December 2018

Potassium (K) is required for successful carrot (Daucus carota) production on sandy soils of the southeastern United States, yet there is little published research documenting most current university Cooperative Extension Service recommendations. Soil test methods for K in carrot production have not been rigorously validated. Excessive fertilization sometimes is practiced by carrot growers to compensate for potential losses of K from leaching and because some growers believe that high rates of fertilization may improve vegetable quality. Carrots were grown in three plantings during the winter of 1994-95 in Gainesville, Fla., to test the effects of K fertilization on carrot yield and quality on a sandy soil testing medium (38 ppm) in Mehlich-1 soil-test K. Large-size carrot yield was increased linearly with K fertilization. Yields of U.S. No. 1 grade carrots and total marketable carrots were not affected by K fertilization. K fertilizer was not required on this soil even though the University of Florida Cooperative Extension Service recommendation was for 84 lb/acre K. Neither soluble sugar nor carotenoid concentrations in carrot roots were affected by K fertilization. The current K recommendation for carrots grown on sandy soils testing 38 ppm Mehlich-1 K could be reduced and still maintain maximum carrot yield and root quality.