bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen, Phosphorus, and Potassium Fertilization Effects on Nutritional Composition of Lettuce
Authors: Hoque* Murshidul , Ajwa Husein , Mou Beiquan
Published: February 2019

Lettuce (Lactuca sativa L.) is an essential salad crop in the American diet. Nitrogen (N), phosphorus (P), and potassium (K) are required for successful lettuce production and can influence lettuce quality. The objective of the study was to evaluate changes in nutritional composition of romaine (`Green Tower') and iceberg (`Sharp Shooter') lettuce in responses to N, P and K fertilization during fall production in Salinas, Calif. Sixteen treatment combinations of fertilizer were selected to provide a range of treatments. N was applied at 0, 112, 225, and 338 kg·ha-1 as ammonium nitrate; P was applied at 0, 112, and 225 kg/ha as super phosphate; and K was applied at 0 and 112 kg·ha-1 as muriate of potash. Nutritional content of fresh tissue of two types of lettuce was analyzed using high performance liquid chromatography (HPLC). Among the parameters analyzed were lutein, beta-carotene, chlorophyll a, and chlorophyll b. Yield was increased with increasing N fertilizer level, but was not affected by P or K application rates. The best post harvest quality, however, was at moderate P application rate. Increasing the N and P rates gradually increased glucose content in lettuce but decreased the shelf life. Significant differences between the two types of lettuce were found in chlorophyll, lutein and beta-carotene content. No significant correlations were found between soil fertilizer application levels and nutritional content of lettuce. However, the ratio of chlorophyll a and b were greater with the increase of fertilizer rate. Nutritional composition including vitamin C will be presented.
Advantages and Limitations of Grafted Vegetable Transplants in Israel
Authors: Koren* Amnon , Edelstein Menahem
Published: February 2019

Grafting technology for vegetable transplants was introduced to Israel eight years ago by Hishtil Nurseries, Inc. The main goal of grafting was to find a substitute for methyl bromide, the elimination of which was pending. The use of grafted watermelon transplants soon followed. Presently, more than 40% of watermelon transplants are grafted. The chief reason for the success of grafted transplants is their tolerance to soil-borne pathogens, including Fusarium, Monosporascus, and Macrophomina. Yields of grafted transplants are often much higher, and it has been shown possible to grow watermelons with saline water (4.5). A limitation of grafted transplants is that presently, we do not have a good solution for nematodes. A drawback is that in order to get good watermelon taste and flavour, the grower needs the experience to adjust agrotechniques, especially determining the best harvest date. Grafted tomato transplants were also introduced early on. Grafted tomato transplants can have excellent resistance to fusarium crown rot, corky root, and other soil-borne pathogens. Some rootstocks have been observed to tolerate water salinity of 8 ec and still produce commercially acceptable yields. Limitations to the use of grafted tomato transplants are the lack of compatibility of some of the cultivars with the rootstocks and the breakdown of nematode resistance at high soil temperatures. Melons, eggplants, and cucumbers are grafted under some conditions.
The Boulder County Jail Project
Authors: Badertscher* Kerrie B. , O'Meara Carol A.
Published: February 2019

The Boulder County Jail Garden was conceived to provide inmates at the jail an opportunity for community service time during their sentence. The jail kitchen needed fresh produce, but costs were rising and variety of choices suffered. In 1994 the Boulder County Jail staff contacted the Colorado Master Gardener™ program (MG), Boulder County, to work on a joint project in tending a 1.1-acre food production garden. Net pounds of produce have increased steadily over succeeding years from 6,300 lbs. in 1997 to 19,100 lbs. in 2003. Market value of 2003 crop is $22,700.00. Communities must be willing to have a volunteer group that can commit to long-term time investment in working the garden each year. MG's participate as mentors to inmates. Discussion outlines activities and critical components for a successful program.
Evaluation of Organic Herbicides
Authors: Ferguson* James
Published: February 2019

Cover crops, cultivation, flaming, soil solarization, and mulching are commonly used for weed control in organic production systems. However, several new herbicides, approved by the Organic Materials Review Institute (OMRI), are recommended as contact, non-selective, post-emergence herbicides for annual grasses and broadleaf weeds. Citric acid (Alldown), clove oil (Matran 2), thyme/clove oil (XPRESS) were compared with glyphosate (Roundup Pro), a systemic broad spectrum herbicide, at three sites in southern and north central Florida during September and October, 2003. Treatments varied at each site but included glyphosate (5% a.i. applied to runoff) organic herbicides at recommended rates (undiluted citrus acid at 61 L·ha-1; 10% clove oil at 76 L·ha-1; 10% clove oil/thyme oil at 76 L·ha-1) and at twice recommended concentrations and application rates. Grasses and broadleaf weed species were different at each site but included Alexander grass, bahia grass, Bermudagrass, carpetweed, crabgrass, hairy indigo, lambs quarters, Florida pusley, goatweed, nutsedge, pigweed, shrubby primrose willow, broadleaf signalgrass, southern sandbur, spurge, torpedograss, and citrus rootstock seedlings. Weed control with the organic herbicides at all three sites at recommended and at higher concentrations and rates was inconsistent, ranging from 10% to 40%, compared with 100% control with glyphosate. Labels for the organic herbicides generally specify application to actively growing weeds less than 10 cm tall, emphasizing their use as early season herbicides. Fall applications to larger weeds, some within the specified maturity and size range and others taller and producing seed, could partially explain poor weed control.
Analysis of Genetic Relationships of Calathea Species and Cultivars by AFLP Markers
Authors: Chen* Jianjun , Henny Richard , Chao C. Thomas , Devanand Pachanoor
Published: February 2019

Calathea, the largest genus in the family Marantaceae, is composed of 100 species native to tropical America in moist or swampy forest habitats. Because of their brilliant patterns of leaf color and different textures plus ability to tolerate low light levels, calatheas have been widely produced as ornamental foliage plants for interiorscaping. Thus far, genetic relationships among its species and cultivars have not been documented. This study analyzed the relationships of 34 cultivars across 14 species using amplified fragment length polymorphism (AFLP) markers. Six EcoR I + 2/Mse I + 3 primer set combinations were used in this investigation. Each selected primer set generated 105 to 136 scorable fragments. A total of 733 AFLP fragments were detected of which 497 were polymorphic (68%). A dendrogram was constructed using the unweighted pair-group method of arithmetic averages (UP-GMA) technique and a principal coordinated analysis (PCOA) was used to analyze the relationships. The 34 cultivars were divided into four clusters. Cluster I had 19 cultivars derived from C. roseo-picta and C. loesnerii with Jaccard's similarity coefficients from 0.74 to 0.97, of which six are somaclonal variants or sports and two cultivars are genetic identical. Only C. kennedeae `Helen' is positioned in cluster II. Cluster III had 10 cultivars across seven species; Jaccard's similarity coefficients among them varied from 0.41 to 0.63. Four species were situated in cluster IV with Jaccard's similarity between 0.27 to 0.41. Results from this study indicate that broadening of genetic diversity is needed for cultivars in cluster I as they are the most commonly grown calatheas but genetically are very close.
Crape Myrtle (Lagerstroemia sp.) Growth and Quality as Affected by Cultivar and Salt Stress
Authors: Cabrera* Raul I.
Published: February 2019

Rooted liners of the crape myrtle cultivars `Pink Lace', `Natchez' and `Basham's Party Pink' (`BPP') were grown in 20-L containers filled with a 2 peat: 1 pine bark: 1 sand (v/v) medium and irrigated for 15 weeks with irrigation water containing 0, 3, 6, 12, and 24 mm NaCl. Cultivar selection and salinity significantly affected plant growth and quality. Regardless of salinity level, `Natchez' plants had higher leaf area, total and shoot (top) dry weights and growth indices, whereas `Pink Lace' had the lowest. `BPP' had the highest average root dry weights across salt treatments. The vigorous shoot (top) growth of `Natchez' was also evident with an average shoot to root ratio of 4.1, compared to 2.7 and 2.4 for `BPP' and Pink Lace', respectively. Salinity significantly decreased plant growth and quality in the three cultivars, but the rate at which these parameters were reduced with increases in salinity differed among the cultivars. The rate of reduction in plant growth parameters was lower in `Pink Lace' plants compared to `Natchez' and `BPP'. However, foliage burn symptoms due to salt stress increased at significantly higher rate for `Pink Lace' plants compared to the other two cultivars. `BPP' plants had in general the lowest salt burn ratings at each salinity level. Leaf concentrations of Na and Cl increased with salt stress in all cultivars, but significantly lower concentrations were found in `BPP' plants. `Pink Lace' plants had better correlations with the recorded salt burn symptoms as compared to the other two cultivars.
Chilling Duration, Container Size and Photoperiod Influence Flowering of Aruncus `Misty Lace'
Authors: Armitage* Allan M. , Wetzstein HazelY. , Anderson Stephanie L. , Hirsch Gwen N.
Published: February 2019

Aruncus `Misty Lace is a new hybrid selection between Aruncus dioicus and A. aethusifolius. The plants outstanding characteristics include heat tolerance, dwarf stature, and delicate, plume-like flowers. The objectives of this study were to evaluate the effect of different production parameters (chilling duration, container size, and photoperiod) on flowering in this new genotype Tissue cultured plantlets of Aruncus `Misty Lace' were transplanted to 72- or 36-cell trays and to 10-cm pots. Transplanted materials remained on the greenhouse bench until roots were visible in the soil plug, then placed in a cooler at 2-4 °C for 0 (control), 4, 6, 8, 10 and 12 weeks of chilling. Upon removal, plants were placed in a greenhouse in 10-cm containers under long or short day photoperiods until flowering, or until the experiment was terminated. Plants required less time on the bench to flower as cooling time increased, regardless of container size. Plants flowered earlier under long days than short days, but photoperiod was less of a factor in the control of flowering than cooling duration. Death of plants was greatest in the 72-plug cells and least in 10-cm pots. Plants without well established root growth sustained significant losses, regardless of container size.
Variation in Fusarium-induced Ethylene Synthesis Among Tulip Cultivars
Authors: Miller* William B. , Verlouw Martijn , Liou Susan S. , Cirri Holly O. , Snover-Clift Karen , Watkins Chris
Published: February 2019

Ethylene evolution is a consequence of Fusarium infection of tulip bulbs, yet little is known about the bulb-pathogen interactions involved in the induction or time course of ethylene synthesis. The resulting ethylene can affect adjacent, non-infected bulbs, and results in a variety of disorders, most notably flower abortion. Earlier work indicates that cultivars vary in their sensitivity to ethylene, but there are few data on ethylene production by cultivar. In this experiment, we assessed Fusarium-induced ethylene production in 36 tulip cultivars. Bulbs were wounded, inoculated with a liquid Fusarium suspension (isolated from infected bulbs) and held at 25 °C. Control bulbs were wounded, but not inoculated. Ethylene production was monitored by headspace analysis and gas chromatography. Ethylene increased rapidly after a lag phase of at least 8 days, but there were large differences in ethylene production among cultivars. Of the cultivars tested, `Furand' evolved more than 340 μL/kg/fwt/hr (≈250 μL/L/bulb/day) on the 11th day after infection, a rate ≈440-fold greater than in non-inoculated bulbs. Inoculated cultivars producing ethylene at rates exceeding 50 μLL/kg/hr included `Mary Belle', `Libretto', `Nashville', `Yonina', `Friso', and `Prominence'. About 25% of the cultivars produced ethylene at rates >10 μL/kg/hr, and ≈40% of cultivars produced less than this rate on day 11. High-ethylene producing tulips could be stored separately from other cultivars, or be given increased ventilation during storage or transportation. Knowledge of cultivar variation might also be useful in breeding programs. Further questions concerning the specific tissue responsible for ethylene synthesis (bulb, fungus, or both?) also arise.
Characterization of Floral Initiation and Development in Hydrangea macrophylla Cultivars Varying in Re-blooming Capacity
Authors: Orozco-Obando* Warner , Wetzstein Hazel Y.
Published: February 2019

Recently, the release of Hydrangea cultivars with the capacity to produce a second flush of blooms has created a great expectation in the ornamental industry. However, the lack of fundamental information on flower development of big leaf Hydrangea does not allow a descriptive explanation of why re-blooming capacity occurs. The objectives of this study were to characterize the timing and location of flower initiation and development in several H. macrophylla cultivars throughout an annual cycle. Four cultivars were evaluated: 2 exhibiting re-flowering capacity (Penny Mac-PM and Endless Summer-ES) and 2 without (Madame Emile Mouillere-MEM and Nikko Blue-NB). Plants were managed under outdoor nursery conditions and harvested at each of four different time periods. These periods represented key developmental stages: 1) Pre-induction: late summer, after completion of shoot expansion; 2) Post-induction: late fall, following short day and cold temperature exposure; 3) Dormancy: winter, post leaf abscission; and 4) Post-dormancy: early spring, just prior to bud break. At each sampling time, bud location (terminal or lateral) and stem origin (basal, lateral, terminal, or secondary) were established. All buds >;2 mm were dissected under a stereomicroscope and the degree of floral induction was determined. Floral primordial were initiated not only in the terminal buds but also within axillary buds. The degree of induction and development varied according to the stem origin, bud location and cultivar. Cultivars with re-blooming capacity had floral primordial initiated within buds at the first sampling period prior to receiving inductive conditions. This suggests they may have minimal or no photoperiodic/temp requirements for flowering.
Radish (Raphanus sativus) as a Model System for the Study of Soil Moisture Effects on the Glucosinolate-myrosinase Complex
Authors: Radovich* T.J.K. , Streeter J.G. , Ling P.P. , Kleinhenz M.D.
Published: February 2019

Clarifying the influence of abiotic environmental factors on the glucosinolate-myrosinase complex in vegetables of the Brassicaceae is an important step in understanding physiological processes that affect crop quality. Previous related work in this lab has shown that irrigation timing in the field may influence physical-, chemical- and sensory-based indicators of cabbage quality. The objective of this study was to record glucosinolate concentrations and myrosinase activity in crop tissues from plants subjected to varying soil moisture levels, employing radish as a model. Plants of cv. Belle Glade were grown in a controlled environment system designed at the Ohio Agricultural Research and Development Center in Wooster, Ohio for maintenance of target soil moisture levels. Pots were maintained at three soil moisture ranges, 40% to 60% (A), 20% to 30% (B) and 10% to 20% (C) volumetric soil moisture content at 30 °C. Preliminary observations revealed that treatments A, B and C corresponded to soil tensions which were not stressful, moderately stressful, and severely stressful to plants, respectively. Pot evapotranspiration, leaf stomatal conductance and plant size followed the order A>B>C, while canopy temperatures followed the order C>B>A. In leaves, glucosinolate concentrations and myrosinase activity were about 15% greater in treatments B and C than in A, while glucosinolate levels and myrosinase activity were 28 and 50% lower in hypocotyls and roots, respectively, in C than in A. It is hypothesized that changes in enzyme and substrate synthesis and translocation within the plant in response to sub-optimal soil moisture levels may explain the differential response of tissue glucosinolate concentrations and myrosinase activity to soil moisture treatments.
Trinexapac-ethyl and Paclobutrazol Protect against Drought in Hot Pepper Plants
Authors: Phavaphutanon* Lop , Hebbe Yonit , Cohen Shlomo , Klein Joshua D.
Published: February 2019

Compounds that modulate the synthesis of gibberellin (GA) can also enhance resistance to abiotic stress in treated plants. Seed treatments of 600 ppm trinexapac-ethyl (TE), which inhibits GA synthesis by blocking the transformation of GA20 to GA1 and foliar applications of 15 ppm paclobutrazol (Paclo), which inhibits the oxidation of ent-kaurene to kaurenoic acid, were applied separately or together to three varieties of hot pepper (Capsicum annuum L.) that are popular in Thailand. Greenhouse-grown plants were subjected to 7-10 days of drought, and then rewatered before transfer to a screenhouse. Khee Noo (an upright “bird type” pepper) was most sensitive to drought, compared to Bang Chang and Hot (“cayenne type”). In all varieties, both Paclo and TE treatments reduced the height of irrigated plants, but led to the retention of both plant size and pepper yield in droughted plants, compared to either irrigated plants or to untreated droughted plants. Treatment with Paclo provided the greatest retention of leaf relative water content (RWC) under drought conditions, with no advantage to the combination Paclo+TE treatment. Only Paclo treatment increased leaf thickness in Bang Chan and Hot, whereas both Paclo and TE had similar effects on increasing leaf thickness in Khee Noo. Khee Noo was the variety most responsive to Paclo or TE treatments, with increases in leaf thickness, epicuticular wax, and leaf pigments, all of which may better allow the plants to survive stress by storing leaf moisture, enhancing photosynthesis (chlorophyll), and preventing oxidative injury (carotenoids). Electrolyte leakage, indicative of membrane permeability and thus of susceptibility to stress, was diminished by 25% to 33% in leaves from plants treated with Paclo or TE.
Effect of Winter Root-zone Temperature on Root Regeneration of Peach Rootstocks
Authors: Okie W.R. , Nyczepir A.P.
Published: February 2019

Roots of dormant peach trees can grow when soil temperatures are >7 °C, which commonly occurs in the southeastern U.S. during the winter. In our tests, root growth on 1-year-old nursery trees was minimal at 7 °C, and increased with temperature up to at least 16 °C, but rootstocks varied greatly in their regeneration at a given temperature. Trees on seedling rootstocks of `Guardian™', `Halford' and `Lovell' regenerated roots more slowly than those on `Nemaguard' at soil temperatures >7 °C. The regeneration rates mirrored the relative susceptibility of these rootstocks to peach tree short life syndrome in the southeastern U.S., which is associated with parasitism by ring nematode.
Harvest Date Effect on Yield and Controlled-atmosphere Storability of Short-day Onions
Authors: Boyhan George E. , Purvis Albert C. , Hurst William C. , Torrance Reid L. , Paulk J. Thad
Published: February 2019

This study was undertaken to evaluate the effect of harvest date on yield and storage of short-day onions in controlled-atmosphere (CA) storage conditions. In general, harvest yields increased with later harvest dates. Yields of jumbo (>7.6 cm) onions primarily showed a quadratic or cubic response to harvest date, first increasing and then showing diminished or reduced marginal yields. Medium (>5.1 to ≤7.6 cm) onions generally showed diminished yield with later harvests as jumbos increased. Neither days from transplanting to harvest nor calculated degree days were reliable at predicting harvest date for a particular cultivar. Cultivars (early, midseason, and late maturing) performed consistently within their harvest class compared to other cultivars for a specific year, but could not be used to accurately predict a specific number of days to harvest over all years. Only three of the eight statistical assessments of percent marketable onions after CA storage were significant with two showing a linear increase with later harvest date and one showing a cubic trend, first increasing, then decreasing, and finally increasing again based on harvest date.
The Effect of Temperature on Leaf and Flower Development and Flower Longevity of Zygopetalum Redvale `Fire Kiss' Orchid
Authors: Lopez Roberto G. , Runkle Erik S.
Published: February 2019

The vegetatively propagated `Fire Kiss' clone of the hybrid Zygopetalum Redvale orchid has appealing potted-plant characteristics, including fragrant flowers that are waxy lime-green and dark maroon with a broad, three-lobed, magenta and white labellum. We performed experiments to quantify how temperature influenced leaf unfolding and expansion, time from visible inflorescence to flower, and longevity of individual flowers and inflorescences. Plants were grown in controlled-environment chambers with constant temperature set points of 14, 17, 20, 23, 26, and 29 °C and an irradiance of 150 μmol·m-2·s-1 for 9 h·d-1. As actual temperature increased from 14 to 25 °C, the time to produce one leaf decreased from 46 to 19 days. Individual plants were also transferred from a greenhouse to the chambers on the date that an inflorescence was first visible or the first flower of an inflorescence opened. Time from visible inflorescence to open flower decreased from 73 days at 14 °C to 30 days at 26 °C. As temperature increased from 14 to 29 °C, flower and inflorescence longevity decreased from 37 and 38 days to 13 and 15 days, respectively. Data were converted to rates, and thermal time models were developed to predict time to flower and senescence at different temperatures. The base temperature was estimated at 6.2 °C for leaf unfolding, 3.5 °C for time to flower, and 3.7 °C for flower longevity. These models could be used by greenhouse growers to more accurately schedule Zygopetalum flowering crops for particular market dates.
Effects of Powdery Mildew of Grape on Carbon Assimilation Mechanisms of Potted `Chardonnay' Grapevines
Authors: Nail William R. , Howell G. Stanley
Published: February 2019

Potted grapevines (Vitis vinifera L. `Chardonnay') were inoculated with conidial suspensions of the grapevine pathogen causing powdery mildew of grape (GPM) (Uncinula necator (Schw.) Burr.). Leaves of inoculated and noninoculated vines were studied for the effects of varying light (PAR) and CO2 concentrations on factors affecting carbon assimilation. GPM reduced carboxylation efficiency (k), net CO2 assimilation rate (A), stomatal conductance (gs), and internal CO2 concentration (Ci) under ambient CO2, Amax at >900 ppm CO2, stomatal limitations to A (lg), and photochemical efficiency (Φ) on diseased leaves, while having no effect on the CO2 compensation point (Γ) or the light compensation point (cp). GPM had no significant effect on chlorophyll fluorescence (Fv/Fm).
Improved Rooting and Acclimatization of Micropropagated Hazelnut Shoots
Authors: Nas Mehmet Nuri , Read Paul E.
Published: February 2019

Microshoots of four hazelnut genotypes grown in vitro on Nas and Read medium (NRM) containing various combinations of CuSO4 • 5H2O and myo-inositol were successfully rooted and acclimatized ex vitro without any need of in vitro hardening treatments. Dipping of shoot bases in 1000 ppm indole-3-butyric acid (IBA) solution for 5 or 10 seconds followed by placement of shoots in plant growth regulator free NRM gave rise to formation of roots as early as 8 days. Shoots treated for 5 and 10 seconds rooted similarly, and depending on genotype, 88% to 98% rooting was observed within 15 days after treatment with IBA. Ex vitro survival of shoots three months after in vitro-root induction was 73% when shoots were treated with IBA for 5 seconds and 66% when shoots were treated for 10 seconds. The highest ex vitro survival rate (97%) 3 months after root induction was observed when shoots were treated with IBA solution for 10 seconds, and then cultured directly in peat pellets. Shoots developed good roots, and grew up to 70 cm in height 3 months after root induction. The potential use of rooting and acclimatization protocol for commercial micropropagation of hazelnut is presented.
Minimum Water Requirements of Four Turfgrasses in the Transition Zone
Authors: Fu Jinmin , Fry Jack , Huang Bingru
Published: February 2019

Water requirements for `Meyer' zoysiagrass (Zoysia japonica Steud., hereafter referred to as zoysia), `Midlawn' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy, hereafter referred to as bermuda], `Falcon II' tall fescue (Festuca arundinacea Schreb.) and `Brilliant' kentucky bluegrass (Poa pratensis L., hereafter referred to as bluegrass) were evaluated under a mobile rainout shelter at deficit irrigation levels of 20% to 100% of actual evapotranspiration (ETa), applied twice weekly, between June and September 2001 and 2002. Soil was a river-deposited silt loam (fine, montmorillonitic, mesic Aquic Arquidolls). Minimum annual irrigation amounts required to maintain quality ranged from 244 mm for bermuda to 552 mm for bluegrass. Turfgrass species and respective irrigation levels (% of ETa) at which season-long acceptable turf quality was maintained in each year were bluegrass, 100% (evaluated 2001 only); tall fescue, 60% in 2001 and 80% in 2002; bermuda, 60% in both years; and zoysia, 80% in both years. A landscape manager who could tolerate one week of less-than-acceptable quality could have irrigated tall fescue at 40% ETa (224 mm) in 2001 and 60% ETa (359 mm) in 2002. Likewise, bermuda exhibited unacceptable quality on only one September rating date when irrigated at 40% ETa (163 mm) in 2001. Bermuda was able to tolerate a lower leaf relative water content (LRWC) and higher level of leaf electrolyte leakage (EL) compared to other grasses before quality declined to an unacceptable level.
(242)`Black Pearl':A New OrnamentalCapsicum
Authors: Stommel John R. , Griesbach Robert J.
Published: February 2019

Considerable diversity exists in Capsicum L. germplasm for fruit and leaf shape, size and color, as well as plant habit. This morphological diversity, together with diverse ripe fruit color and varying hues of green to purple and variegated foliar pigmentation, affords myriad opportunities to develop unique cultivars for ornamental applications. The Agricultural Research Service of the United States Department of Agriculture announces the release of a new pepper [Capsicumannuum (L.)] cultivar named `Black Pearl'. `Black Pearl' is intended for ornamental applications and affords growers a new crop to add to their bedding and landscape plant assortment. `Black Pearl' combines black foliage with erect clusters of small round red-pigmented fruit. The vibrant fruit and foliage colors of this new cultivar add interest to the summer and fall garden. Black Pearl' has been trialed extensively for use as a bedding plant where its compact growth habit, black foliage, and brightly colored fruit provide an attractive ornamental display. Limited evaluations suggest that this cultivar is equally well suited for pot culture under high light conditions. `Black Pearl' was designated a 2006 All America Selection award winner after completion of national trials in 2004. `Black Pearl' is a release made available from a cooperative research and development agreement with Pan American Seed Company. Seed of `Black Pearl' is available from Pan American Seed Company, 622 Town Road, West Chicago, IL 60185. Plant Variety Protection for `Black Pearl' is pending.
(32) Effects of 1-MCP Treatments on Several Major Apple Cultivars Grown in Korea
Authors: Jung Seok-Kyu , Lee Jung-Myung
Published: February 2019

Fruits of `Tsugaru' (an early maturing cultivar), `Hongro' (mid-season cultivar), and `Fuji' (late cultivar), were harvested at different times of the year, depending upon their maturity, and treated with 1-MCP at 0.0, 0.5, 1.0, and 2.0 ppm for 8-24 hours. Fruits were also treated with 1-MCP at different times after harvest. Portions of 1-MCP-treated apples were also treated with ethylene in order to study the interaction between 1-MCP and ethylene. In other experiments, fruits were treated with ethylene first and then treated again with 1-MCP. Major results are as follows. Treatment of 1-MCP greatly retarded the senescence of `Tsugaru' apple stored at room temperatures as compared with the control. The sooner the time of 1-MCP treatment after harvest of fruit, the greater was the 1-MCP effect. In contrast to the time of 1-MCP treatment, the concentration of 1-MCP and duration of 1-MCP infiltration in a closed chamber exhibited only a minor effect. Ethylene treatment immediately before and/or after the 1-MCP treatment showed only the 1-MCP effect, thus clearly showing that 1-MCP treatment could completely reverse or counter the ethylene effect in `Fuji' apples. Repeated treatments of 1-MCP after a certain period of low temperature storage of `Fuji' apples were more effective than a single treatment. Parameters related with fruit quality will be discussed in detail.
(33) Effect of Natural Products on Decay and Antioxidant Activities of Fresh-cut Papayas
Authors: Wang Chien , Chanjirakul Korakot , Wang Shiow , Siriphanich Jingtair
Published: February 2019

The effect of naturally occurring volatile compounds on decay and antioxidant activities in fresh-cut papayas (Carica papaya L.) was studied. Exposure to methyl jasmonate (MJ), methyl salicylate (MS) or allyl isothiocyanate (AITC) substantially delayed the onset and reduced the severity of decay during and after storage at 5 °C. Treatment with tea tree oil (TTO) or ethanol (ETOH) was also effective in retarding decay, but to a lesser extent. No beneficial effect was obtained with the use of vinegar vapor. MJ and MS increased oxygen radical absorbance capacity and elevated the activities of several antioxidant enzymes, including glutathione reductase, glutathione peroxidase, guaiacol peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and superoxide dismutase. The nonenzyme components in the ascorbate-glutathione cycle were also increased by MJ and MS treatments, including ascorbate and glutathione. It is possible that MJ and MS treatments enhanced the antioxidant system and increased the resistance of tissue to decay. However, while AITC also suppressed the development of decay in papaya slices, it had little effect on antioxidant levels and antioxidant enzyme activities. Apparently, AITC exerted its effect through different mechanisms. Studies are in progress to determine if AITC inhibits decay directly via its antimicrobial properties.
(161) Use of Food Waste Composts in Ornamental Plant Production in Florida
Authors: Riffo Olivia , Ozores-Hampton Monica
Published: February 2019

The nursery industry in Florida relies entirely on peat as a major component in potting soil. Escalating peat costs are a major concern, so alternative media are attractive in Florida. The objectives of the project were to study the feasibility of using food waste compost (FWC) to replace peat in different annual ornamental crops. The experiments were conducted in Spring 2004 at the University of Florida/SWFREC Immokalee, Fla. The crops basil (Ocimum basilicum L.), marigold (Calendulaofficinalis L.), and periwinkle (Vincarosea L.) were grown in mixes of FWC. The treatments were: 1) 100% FWC; 2) 60% FWC, 25% vermiculite, 15% perlite; 3) 30% FWC, 30% peat, 25% vermiculite, 15% perlite; and 4) 0% FWC, 60% peat, 25% vermiculite, 15% perlite, by volume. Basil `U.H' was direct seeded; marigold and periwinkle were transplanted (5 cm tall) in pots (2 inches). All treatments received 4 g per pot of Osmocote (19-6-12) for 4 months. Percentage of basil germination and biomass were higher in mixes with 60% and 30% FWC as compared with 100% FWC and the control. Lower basil biomass in the control media was due to high weed biomass grown in the peat control media. There were no differences in biomass and number of flowers per plant among marigold treatments. But, periwinkle dry biomass and number of flowers per plant were higher in the control and 30% FWC than in 60% and 100% FWC, indicating a negative effect of FWC in periwinkle. It can be concluded that FWC may become a viable alternative to replace peat in basil and marigold when included in potting mixes between 30% and 60% by volume, but a negative effect was reported in periwinkle production.
(294) Radiation Cycle Affects Biomass Production and Carotenoid Accumulation in Kale
Authors: Lefsrud Mark G. , Kopsell Dean A.
Published: February 2019

Plant growing systems have consistently utilized the standard Earth day as the radiation cycle for plant growth. However, the radiation cycle can easily be controlled by using automated systems to regulate the exact amount of time plants are exposed to irradiation (and darkness). This experiment investigated the influence of different radiation cycles on plant growth, chlorophyll and carotenoid pigment accumulation in kale (Brassica oleracea L. var. acephala D.C). Kale plants were grown in growth chambers in nutrient solution culture under radiation cycle treatments of 2, 12, 24, and 48 h, with 50% irradiance and 50% darkness during each time period. Total irradiation throughout the experiment was the same for each treatment. Radiation cycle treatments significantly affected kale fresh mass, dry mass, chlorophyll a and b, lutein, and beta-carotene. Maximum fresh mass occurred under the 2-h radiation cycle treatment. The maximum dry mass occurred under the 12-h radiation cycle treatment, which coincided with the maximum accumulation of lutein, beta-carotene, and chlorophyll a, expressed on a fresh mass basis. The minimum fresh mass occurred during the 24 h radiation cycle treatment, which coincided with the largest chlorophyll b accumulation. Increased levels of chlorophyll, lutein and beta-carotene were not required to achieve maximum fresh mass production. Environmental manipulation of carotenoid production in kale is possible. Increases in carotenoid concentrations would be expected to increase their nutritional contribution to the diet.
(306) NFT versus Subirrigation: I. Yield and Water Use Efficiency of Tomato Grown in Closed Soilless Systems under Salinity or Water Stress
Authors: Montesano Francesco , Favuzzi Gianfranco , Parente Angelo , Serio Francesco , Santamaria Pietro
Published: February 2019

Sustainability of the soilless greenhouse system is under discussion in open cycle systems, where excess nutrient solution (NS) draining from the substrate is released into the environment. Closed growing systems (CGS) lead to the saving of water and fertilizers. The aim of this research was to compare two CGS: nutrient film technique (NFT) and trough-bench technique [Subirrigation (SUB)]. We report the results of yield and water use efficiency (WUE) of tomato (Lycopersicon esculentum Mill. cv. Kabiria) plants. NFT plants were grown with two electrical conductivity (EC) levels (2-4 and 6-8 dS·m-1) of NS (its highest EC was obtained by increasing all the ions therein). In the SUB system, two water tensions (-4 and –8 kPa) of susbtrate were compared; a NS with an electrical conductivity level of 2 dS·m-1 was used. The tensions were measured through tensiometers. Tomato plants were transplanted at the fourth to fifth true-leaf stage into pots containing 8 L of perlite for SUB. In both CGS, the plants were placed on steel gullies (slope of 2%). Six clusters per plant were harvested. Total and commercial yield were not influenced by the CGS (on average, 1959 and 1853 g/plant, respectively). The average weight of the fruit was lower in the SUB system's plants (40 vs. 43 g/fruit, respectively, for SUB and NFT). Salinity and water stresses resulted in a reduction of 26% of the yield and 16% of the average weight of fruits. The WUE was higher in SUB than NFT (30.7 vs. 26.0 g·L-1, respectively). Salinity stress reduced WUE (29.4 v.s 22.6 g·L-1 with 2–4 and 6–8 dS·m-1, respectively), whereas water stress did not.
(308) Irrigation Strategies for Rockwool-grown Greenhouse Tomatoes
Authors: Papadopoulos Athanasios , Saha Uttam , Hao Xuiming , Khosla Shalin
Published: February 2019

In rockwool-grown greenhouse vegetables, unsatisfactory spatial root development, rapid root collapse, and increased incidence of root diseases are very common. Improved water management could alleviate these problems to some extent, because this could favorably modify water-air distribution in the slab, thereby improving greenhouse vegetable yield and quality. The present study tested six irrigation strategies on the productivity of rockwool-grown tomatoes (cv. Rapsodie) during Jan.o–Aug. 2004. The four treatments, based on electronic Grodan? water content meters (WCMs), received irrigations when the slab water content (SWC) was ≈60%, 70%, 80%, and 90% while the other two treatments, based on balances, applied irrigations after a 700- or 500-g loss in the daily-adjusted slab weight (LDASW). Initially, we noticed a heterogeneous EC build-up in the slabs across various treatments, which probably distorted the expression of treatment effects (if any) on plant growth, yield, and water use. To minimize this problem, an EC control strategy of applying extra irrigation was devised and adopted in two sequential phases: 1) application of a 30-minute-long extra irrigation twice a week (for 7 weeks); and 2) extra irrigation(s) using the irrigation control routine of an Argus computer when the slab EC was ≈3.5 mS/cm (for 5 weeks). Slab EC was well controlled in both these phases and we observed significant treatment effects on root growth and marketable yield. Analyzing the results, we concluded that irrigating at 70% to 80% SWC was best for maximum root growth as well as marketable yield. The two irrigation treatments based on the 700- and 500-g LDASW were well maintained and performed equally well, producing marketable yields comparable to those produced by irrigating at 70% and 80% SWC.
(76) Thermal Effects on Vegetative Growth and Reproductive Behavior of Phalaenopsis Orchids
Authors: Wang Yin-Tung
Published: February 2019

Since Phalaenopsis orchids are CAM plants, learning how they respond to night temperature warmer than the day would help regulate their production. On 1 Apr. 2003, P. amabilis plants were subjected to day/night temperatures at 30/25, 25/30, 25/20, 20/25, 20/15, or 15/20 °C under 140 μmol·m-2·s-1 PPF. After 4 months, the total length of new leaves was shorter as a result of fewer and shorter new leaves when nights were cooler than the days and as the average daily temperature declined. More spikes were produced at 25/20 and 20/25 °C than at 20/15 or 15/20 °C. In another experiment, P. amabilis plants were moved to the above conditions on 12 Aug. Plants exposed to 30/25 or 25/30 °C had more leaf growth than at lower temperatures, but no flowering. Plants that were exposed to 25/20 or 20/25 °C spiked in 2 weeks; but plants took 20 and 18 d to spike under 20/15 or 15/20 °C, respectively. Again, as average daily temperature decreased, there was less leaf growth. Cooler day than the night reduced vegetative growth, regardless of temperature. Plants at 25/20 or 20/25 °C had higher flower count (12) than those at 20/15 or 15/20 °C (8). In a third experiment, plants of a large-flowered Doritaenopsis hybrid spiked at 22–24 d when exposed to 25/20 or 20/25 °C, whereas 30-33 d were needed to spike under 20/15 or 15/20 °C. In a fourth experiment, a Doritaenopsis hybrid spiked after 22, 21, or 25 d under 25/25, 25/20, or 20/20 °C. However, 37 d was required to spike under 20/15 °C. These results suggest that the best temperature range for spiking these orchids is 25 to 20 °C and a day/night temperature differential is not needed for spiking when temperature is at or below 25 °C.
(269) Taxonomic Relationship of Korean Native Aster, Based on Internal Transcribed Spacer (ITS) Sequences of Nuclear Ribosomal DNA
Authors: Hong Su-Young , Cho Kwang-Soo , Yoo Ki-Oug , Suh Jong-Taek , Yoo Dong-Lim
Published: February 2019

There are 25 species of aster in Korea. There is a controversy about the taxonomical classification of Aster. The genus Aster was classified into four genera, Aster, Gymnaster, Kalimeris, and Heteropappus, by morphological characters. In order to clarify the phylogenetic position of aster, the nucleotide sequence of the nuclear ribosomal DNA internal transcribed spacer (ITS) region was compared among 11 taxa in Korean native aster. The size of ITS1 and ITS2 ranged from 283 to 286 bp and from 251 to 257 bp, respectively. The size of 5.8S region was 164 bp in 11 taxa. The total length of ITS1, 5.8S and ITS2, A. tripolium was shown to be the shortest length, 701 bp; and A. scaber was shown to be the longest length, 706 bp. The G+C content of ITS1 ranged from 47.9% to 51.2% and ITS2 ranged from 52.2% to 55.1%. The range of each taxon was narrow. The total length of the character matrix was 708 characters. Among them, total indel showed 9; in the ITS1 region indel showed 6 it was 67%; and in the ITS2 region, indel showed 3. Most of the indels showed deletion or insertion of only one base pair, but in A. spathulifolius deleted two base pairs and in A. tripolium deleted five base pairs. But in A. yomena, A. hayatae, A. koraiensis, and A. hispidus, the indel was not detected. Phylogenetic trees did not even make a difference inter-genus, but A. yomena and A. koraiensis called genus Kalimeris and genus Gymnaster, respectively; these constituted a clade. A. hispidus called genus Heteropappus was placed as a sister group to the clade of A. ageratoides and A. glehni.
(340) Root Hardiness and the Influence of DNA Herbicides in Overwintered Containers
Authors: Bigger Michele , Mathers Hannah M.
Published: February 2019

A limiting factor in container production is cold temperature. Young roots have been found to be less hardy than mature roots (Steponkus, 1976; Studer et al., 1978). Proper overwintering procedures are essential to assure a viable crop in the spring. A common overwintering practice is the application of a preemergent dinitroanaline (DNA) herbicide prior to covering. The objectives of this research were to: 1) determine young and mature root hardiness values for containerized plants that did and did receive DNA herbicides prior to overwintering; 2) investigate differences in regrowth potential between untreated and DNA herbicide treated containers 30, 60, and 180 days after freezing (DAF). Research began in June 2003 and concluded Mar. 2004. In Aug. and Oct. 2003, herbicide treatments of 1× oryzalin (2.0 lb/acre a.i.), prodiamine (2.0 lb/acre a.i.), pendimethalin (3.0 lb/acre a.i.), trifluralin (2.0 lb/acre a.i.), or no treatment (control) was applied to the plants. In Jan. or Mar. 2004, plants were frozen to temperature treatments of, 0, –5, –10, –15, or –20 °C. After freezing, they were placed in a heated greenhouse and evaluated for regrowth. Regrowth and hardiness were evaluated two ways: by a visual rating score (0-10), where 0 = dead and 10 = healthy; and plant live height. Results pooled over all species, temperatures, sampling dates at 30 DAF show prodiamine significantly increased hardiness (23.7%) compared to the control. Results pooled over all species, temperatures, sampling dates, and all DAF show prodiamine significantly increased regrowth potential (24.5%) compared to the control. Both sampling date and DAF were significant when pooling over all species, temperatures, and herbicide treatments, indicating root injury had occurred.
(342) Cool-season Living Mulchesfor Florida
Authors: Chase Carlene A. , Mbuya Odemari S.
Published: February 2019

Living mulches between beds of polyethylene-mulched vegetable crops may suppress weeds and decrease surface and ground water contamination by pesticides. They should be either low growing or amenable to mowing and should withstand traffic. Twelve winter cover crops were planted in north (N.) and north central (N.C.) Florida in Fall 2004: black oats (Avena strigosa cv. Soilsaver), annual ryegrass (Lolium multiflorum cv. Gulf), rye (Secale cereale cv. Wrens Abruzzi), hard fescue (Festuca longifolia cv. Oxford), white clover (Trifolium repens cvs. Dutch white and New Zealand white), berseem clover (T. alexandrinum cv. Bigbee), crimson clover (T. incarnatum cv. Dixie), subterranean clover (T. subterraneum cv. Mt. Barker), arrowleaf clover (T. vesiculosum cv. Yuchi), a barrel medic (Medicago trunculata cv. Parabinga), and a disc × strand medic (M. tornata × M. littoralis cv. Toreador). Black oats, rye, and annual ryegrass established quickly and suppressed winter annual weeds. Canopy development of the other species was poor. Shoot biomass was greater in N. Florida than in N.C. Florida. The highest shoot biomass occurred with black oats. By 8 weeks after planting (WAP) rye and annual ryegrass had similar amounts of biomass, but by 16 WAP the yield of rye was greater. At some harvests, biomass with wheel traffic or mowing was lower than without, but black oats, rye, and ryegrass did not succumb to these treatments. Of the legumes, only crimson clover and `Toreador' medic in N. Florida produced sufficient biomass by 16 WAP to permit a harvest. Black oats, rye, and annual ryegrass appear to be the best living mulch candidates; however, black oats would require more frequent mowing.
(363) Effect of Visible Light Wavelengths on the Population Growth Rate of the Two-spotted Spider Mite (Tetranychus urticae Koch.)
Authors: Suzuki Takeshi , Amano Hiroshi , Kozai Toyoki
Published: February 2019

The two-spotted spider mite (Tetranychus urticae Koch.) has a worldwide distribution and is one of the most harmful agricultural pests for a variety of plant species. To reveal a visible light wavelength that reduces the population growth rate (as rm, unit: d–1) of the mite, we investigated the rm under wavelength peaks of 468, 515, and 658 nm with half bandwidths of 23, 44, and 22 nm using blue, green, and red light-emitting diodes, respectively. In all treatments, light intensity was set at 2.3 W·m–2 with a light period of 16 h·d–1, and air temperature was set at 25 °C. The survival percentage (lx) and the number of eggs deposited per female (mx) on each age (x, unit: d) were determined to calculate the rm by the following equation: ∑exp(–rm · x)· lx /100 · mx = 1. The rm and the total mx decreased with increasing wavelength. This result shows that the population growth rate can be reduced under red light (658 nm).