bluuebunny/crossref_metadata_2025 huggingface dataset:
Propagation of Sterile Ornamental Pepper by Cuttings and in Vitro Shoot-tip Culture
Authors: Sultanbawa Fazal , Phatak Sharad C.
Published: February 2019

A sterile (nonflowering) mutant pepper plant (Capsicum sp.) with large, purplish-green, leathery leaves and purplish-green stems was observed during a hybridization program for ornamental peppers. Propagation of this mutant was investigated using cuttings rooted in the greenhouse and in vitro cultures. The most suitable treatment for rooting of cuttings involved the use of two-node cuttings, 2 to 4 mm in diameter, treated with Rootone and rooted in Promix inside a humidity chamber kept in 60% shade. With this treatment, 40% of the cuttings had rooted after 8 weeks. Two-node shoot tips callused when cultured in vitro in Murashige and Skoog (MS) medium containing 4.9 or 9.8 μm IBA or 8.8 μm BA, but 60% had rooted after 8 weeks in half-strength MS medium without growth regulators. Chemical names used: 1 H -indole butyric acid (IBA), N -(phenylmethyl)-1 H -purin-6-amine (BA).
Growth Regulators Influence Root and Shoot Development of Micropropagated Algerian Ivy
Authors: Al-Juboory K.H. , Williams D.J. , Skirvin R.M.
Published: February 2019

Shoots of greenhouse-grown Algerian ivy (Hedera canariensis L.) were surface disinfected and explanted on modified Murashige and Skoog (MS) medium supplemented with BA (10 μm) and NAA (2.5 μm). One month later the shoots were transferred to MS proliferation medium supplemented with TDZ (0.1 or 0.5 μm) and NAA (40 μm). An average of three microshoots developed on each stem treated with TDZ. Pruned shoots grown on MS medium supplemented with GA3 (20 μm) and BA (20 μm) branched better than unpruned shoots (3.7 vs. 1 per explant, respectively). Rooted shoots grown ex vitro grew and developed a shape suitable for commercial sale in 3 months. Chemical names used: N -(phenyl-methyl)-l H -purine-6-amine (BA); gibberellic acid (GA3); 1-naphthaleneacetic acid (NM); N -phenyl-W-1,2,3-thiadiazo-5-yl urea (Thidiazuron, TDZ).
Growth Response of Young Peach Trees to Distribution Pattern of Vegetation-free Area
Authors: Welker W.V. , Glenn D.M.
Published: February 2019

Peach (Prunus persica L. Batsch) trees were grown for five growing seasons in uniform-sized vegetation-free areas arranged in three patterns within a tall fescue (Festuca arundinacea Schreb.) sod. Trees grown in a vegetation-free area arranged in a strip pattern grew better than trees grown either in the center or edge of a square. The distribution pattern of the vegetation-free area influenced growth during the first 4 years; however, at the end of 5 years, differences in canopy width and trunk cross-sectional area were minimal. Thus, there is much latitude in distributing the available vegetation-free area as orchard floor management practices dictate.
Sour Cherry Trees Respond to Foliar Boron Applications
Authors: Hanson Eric J.
Published: February 2019

Seven trials were conducted over 3 years in several Michigan locations to study the response of sour cherry (Prunus cerasus L. cv. Montmorency) to foliar B sprays. Orchards ranged in age (6 to 12 years) and leaf B concentrations (19 to 32 μg B/g dry weight). Treatments consisted of a 500 mg B/liter spray applied to leaves in late September or early October, and an untreated control. Boron sprays increased B concentrations in dormant buds and flowers by 94% and 54%, respectively, but did not consistently change leaf levels. Boron applications increased fruit set and production by as much as 100% in one trial, but had no effect in others. Fruit set and production were most consistently increased in trees containing leaf B levels of 19 to 25 μg·g–1 dry weight. In trees with leaf B concentrations of 25 to 32 μg·g–1, responses to B were less consistent and smaller in magnitude.
Rootstock Affects Vegetative Growth Characteristics and Productivity of `Delicious' Apple
Authors: Schechter Ido , Proctor J.T.A. , Elfving D.C.
Published: February 2019

Fruit and leaves were harvested from sample branches in Oct. 1987 and 1988 from `Starkspur Supreme Delicious' apple (Malus domestica Borkh.) trees on nine rootstocks (Ottawa 3, M.7 EMLA, M.9 EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC-9, MAC-24, OAR 1) planted in 1980. Harvested leaves were separated into shoot leaves and spur leaves. Based on a standardized unit (centimeter of limb circumference), rootstocks strongly influenced the number, area, dry weight, and percentage of leaves in each category in both years. Yield per centimeter of limb circumference (limb yield efficiency, LYE) varied widely among rootstocks. LYE was highly correlated with spur density and with spur leaf variables but not with shoot leaf number, dry weight, or area. Rootstock effect on spur density may partially explain their effect on yield characteristics. The rootstock OAR 1 affected some of these characteristics differently than the others.
Feasibility of Trellised Cucumber Production
Authors: Russo V.M. , Roberts B.W. , Schatzer R.J.
Published: February 2019

Trellising was evaluated for its effects on yields of cucumber (Cucumis sativus L.) cultivars Dasher II, Marketmore 76, and PetoTripleMech at Lane and Wilbutton, Okla. Trellising improved total and marketable yield at both locations compared with ground culture. `PetoTripleMech', evaluated as a fresh-market cultivar, produced yields equal to, or higher than, the other cultivars. Average marketable fruit weight was not affected by trellising but was affected by cultivar at Lane, with `PetoTripleMech' having the heaviest fruit. Economic analysis indicated that trellising is a viable management system for small-scale cucumber production.
Seasonal Quality Responses of Perennial Ryegrass as Influenced by Fungicides
Authors: Dernoeden P.H. , McIntosh M.S.
Published: February 2019

Little is known about deleterious or beneficial nontarget effects of fungicides applied to turfgrasses. Five fungicides from several chemical classes were applied six times annually over 5 years to field plots of either `Regal' or `Fiesta' perennial ryegrass (Lolium perenne L.). All fungicides improved turfgrass quality during Spring 1984, Summer 1984 and 1985, Fall 1984, and Winter (except benomyl and chlorothalonil) 1985. Improved quality in Spring 1984 was attributed to red thread [Laetisaria fuciformis (McAlp.) Burds.] control; whereas, improved quality in Summer 1985 was due to brown patch (Rhizoctonia solani Kuhn.) control. For other years and seasons, the mechanism of improved quality provided by the fungicides was not determined. Other than red thread and brown patch control, few nontarget benefits and no nontarget detriments were observed visually with multiple applications of the fungicides evaluated. Chemical names used: methyl[1-butylamino carbonyl]-1H-benzimidazol-2-yl]carbamate(benomyl); tetrachloroisophthalonitrile (chlorothalonil); 1-isopropyl-carbamoyl-3-(3,5-dichlorophenyl) hydantoin (iprodione); bis(dimethyl-thio-carbamoyl) disulfide (thiram); and 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-y1)-2-butanone (triadimefon).
Electrolyte Leakage, Respiration, and Ethylene Production as Indices of Chilling Injury in Grapefruit
Authors: McCollum T.G. , McDonald R.E.
Published: February 2019

Storage of `Marsh' white seedless grapefruit (Citrus paradisi Macf.) for 2 weeks at 5C resulted in the development of chilling injury (CI). Electrolyte leakage from chilled fruit did not increase significantly until CI had become severe, and was therefore considered to be of limited value as an early indicator of CI. In contrast to electrolyte leakage, respiration and ethylene evolution were significantly higher in chilled than in nonchilled fruit, even before the onset of visual symptoms of CI. Respiration rates ranged from ≈8 to 11 and 5 to 7 ml CO2/kg per hour in chilled and nonchilled fruit, respectively. Ethylene evolution was not detected from nonchilled fruit, whereas chilled fruit produced from 45 to 250 nl ethylene/kg per hour. Results of this study indicate that electrolyte leakage does not increase until visible pitting of the flavedo has occurred, whereas stimulation of respiration and ethylene evolution occur early in the development of CI.
Postharvest Quality Characteristics of Cultivars of Potted Rose in Response to Holding Conditions and Cytokinins
Authors: Clark David G. , Kelly John W. , Pemberton H. Brent
Published: February 2019

Six cultivars of potted rose (Rosa ×hybrida L.) plants were evaluated for shipping stress-induced leaf chlorosis during holding at 8, 16, or 28C for 2, 4, or 6 days. `Meijikatar' showed more leaf chlorosis than the similar `Meirutral' at the higher simulated shipping temperatures and longer durations. Plants of `Meijikatar' were treated before simulated shipping with BA, TZ, or Promalin at 0, 25, 50, or 100 mg cytokinin/liter each, then paper-sleeved and stored in the dark in fiberboard boxes at 16C for 5 days. Plant quality 5 days after removal from storage was better with BA at 50 or 100 than at 0 mg·liter–1. All cytokinin-treated plants showed less leaf chlorosis than controls. Benzyladenine at 50 or 100 mg·liter–1 reduced leaf chlorosis when compared to all TZ treatments. There were no differences among treatments in the number of etiolated shoots per plant. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (benzyladenine, BA); trans-zeatin (TZ); gibberellic acid (GA4+7) + BA (Promalin).
Changes in Superoxide Dismutase Activity during Thidiazuron-induced Lateral Budbreak of Apple
Authors: Wang Shiow Y. , Faust Miklos , Jiao Hong J.
Published: February 2019

The effects of thidiazuron on changes in superoxide dismutase (SOD) activity in apple (Malus domestica Borkh cv. York Imperial) buds during dormancy break were determined. Dormant buds had low SOD activity. Increased SOD activity was correlated with budbreak induced by thidiazuron. Buds contained three distinct forms of SOD: Cu, Zn-SOD; Mn-SOD; and Fe-SOD. Most of the SOD activity in apple buds was attributed to Cu and Zn-SOD, followed by Mn-SOD. Iron-SOD was not present in dormant buds, and only a trace amount was found as buds started rapid expansion. Chemical name used: N-phenyl-N′-1,2,3,-thidiazol-5-ylurea (thidiazuron).
Transpiration by Crape Myrtle Cultivars Surrounded by Mulch, Soil, and Turfgrass Surfaces
Authors: Zajicek Jayne M. , Heilman J.L.
Published: February 2019

A study was conducted to explore how surface materials, including pine bark mulch, bare soil, and turfgrass, affect water use of diverse cultivars (dwarf weeping, dwarf upright, standard weeping, and standard upright) of crape myrtle (Lagerstroemia indica L.). Daily water use was measured gravimetrically, and instantaneous rates of sap flow were measured using heat balance stem flow gauges. Plants of all cultivars surrounded by the mulched surface lost 0.63 to 1.25 kg·m-2·day-1 more water than plants on the soil surface and 0.83 to 1.09 kg·m-2·day-1 more than plants surrounded by turf. The surface temperature of the mulch was higher than that of the other surfaces, resulting in greater fluxes of longwave radiation from the surface. Because of the greater energy load, plants on the mulched surface had higher leaf temperatures and higher leaf-air vapor pressure deficits (VPD) throughout the day. Plants on the mulched area also had higher stomata1 conductances during most of the day compared with those on bare soil and turfgrass surfaces.
Performance of 15 Exacum affine Genotypes in a Low-irradiance Environment
Authors: Rubino David B.
Published: February 2019

Fifteen cultivated genotypes of Exacum affine Balf. were evaluated for flower development and for flower and leaf color at 0 days (marketable stage, ≈ 25% of plant canopy covered with flowers), and after 14 and 28 days of maintenance in a low-irradiance environment (≈ 1 μmol·m-2·s-1 photosynthetically active radiation from cool-white fluorescent lights for 12 hours daily). Flowering and flower color development were reduced, but leaf color improved during maintenance under low irradiance. Variability was observed among the 15 genotypes for flower bud and flower color development in a low-irradiance environment.
Relationship of Sweetpotato Yield and Quality to Amount of Irrigation
Authors: Thompson Paul G. , Smittle Doyle A. , Hall Melvin R.
Published: February 2019

A line-source irrigation design was used to provide continuously increasing amounts of irrigation at each application to sweetpotato [Ipomoea batatas (L.) Lam]. Marketable yields increased with applied irrigation amounts until a total water application of 76% of pan evaporation (Epan) was reached and then decreased rapidly with applied irrigation amounts. Weight loss and decay of roots during storage showed quadratic responses to irrigation amounts and were minimal at the irrigation level of maximum yields. Contents of dextrins and maltose increased with irrigation amounts. Glucose content was maximum at a total water amount of 94% Epan and fructose content decreased with increased amounts of irrigation. Sensory ratings for appearance, flavor, texture, and preference, and objective color measurements of cooked flesh also reached their highest values near the irrigation amount of maximum yield.
Rate of Germination and Seedling Growth of Perennial Ryegrass Seed following Osmoconditioning
Authors: Danneberger T.K. , McDonald M.B. , Geron C.A. , Kumari P.
Published: February 2019

This study evaluates the effects of seed osmoconditioning on germination and seedling growth of perennial ryegrass (Lolium perenne L.). Seeds were osmoconditioned in polyethylene glycol 8000 with water potentials ranging from 0 to -1.4 MPa for 48 hours. Osmoconditioning for this crop at -1.1 MPa resulted in a 35% germination increase after 48 hours under optimum (15/25C) germination conditions. This promotive effect was observed until 104 hours for percentage germination and root growth and 118 hours for shoot growth. Rate of seed germination and seedling root growth of osmoconditioned seeds also was enhanced when seeds were placed under suboptimum germination temperatures of 5, 10, and 15C. These results suggest that while osmoconditioning enhanced initial germination rate and seedling root growth under laboratory conditions, it did not do so under prolonged favorable conditions. However, the promotive effects of osmoconditioning were more beneficial when seeds were exposed to less favorable germination conditions.
Treeshelter Use in Producing Container-grown Trees
Authors: Burger David W. , Svihra Pavel , Harris Richard
Published: February 2019

Treeshelters were used for the nursery production of Cedrus deodara Loud. (deodar cedar), Quercus ilex L. (holly oak), and Magnolia grandiflora L. (southern magnolia) trees growing in 19-liter containers. Air temperature, relative humidity, and CO, concentration were higher inside the treeshelters than outside. Trees grown inside treeshelters were 74% to 174% taller than trees grown without shelters. Trunk caliper of Magnolia and Quercus was not affected, however, for Cedrus trees caliper was larger for trees grown without a shelter. Upon removal of the shelter, Cedrus trees were incapable of supporting their own weight. Lateral branch development was inhibited and leaf senescence was greater with Magnolia trees grown in a shelter. Quercus trees grown in shelters were ready to be transplanted into the landscape. Water use was similar for trees grown with or without shelters. Trees grown in shelters had lower root fresh weights.
Effect of Dikegulac on Flowering and Growth of Bougainvillea `Rainbow Gold'
Authors: Norcini J.G. , McDowell J.M. , Aldrich J.H.
Published: February 2019

The use of dikegulac in production of hanging baskets (4.5-liter capacity) of Bougainvillea `Rainbow Gold' was investigated under decreasing daylengths and high temperatures. Liners treated with a single application of 1200 ppm dikegulac 4 weeks after transplanting and pruning (WATP) resulted in the only marketable hanging baskets 9 WATP. Application of 1200 ppm dikegulac 4 WATP enhanced flowering and aesthetic quality compared with plants that had only been pruned. Bract size did not appear to be reduced. Plant width tended to increase as time of application was delayed. Dikegulac had no effect on height or branching. Chemical name used: sodium salt of 2,3:4,6-bis-O-(l-methylethylidene)-a-L-xylo-2-hexulofuranosonic acid (dikegulac-sodium).
Controlled-atmosphere Storage of Sugar Peas
Authors: Ontai Stacey L. , Paull Robert E. , Saltveit Mikal E.
Published: February 2019

Sugar peas (Pisum sativum var. saccharatum cv. Manoa Sugar) were stored for 14 or 21 days under controlled atmospheres (CA) of 21% or 2.4% O2, plus 0%, 2.6%, or 4.7% CO2 at 10 or 1C. Changes in appearance, weight, and in the concentrations of chlorophyll, total soluble sugars, insoluble solids, and soluble protein were evaluated before and after storage. After 14 days of storage at 10C there were minor changes in all indicators of quality under the various storage conditions, but the appearance of sugar peas was better under CA than under 21% O2. When quality was evaluated after 21 days, however, storage under CA at 10C was not as beneficial as storage in 21% O2, at 1C. Holding peas in 2.4% O2, for up to 3 weeks at l0C, a higher than recommended storage temperature, maintained better quality than 21% O2. Increasing the CO, concentration from 0% to 2.6% or 4.7% had no adverse effects on quality and had a beneficial effect in some treatments. Compared with storage in 21% O2, the appearance of the peas was better, the concentrations of chlorophyll and soluble sugar were maintained at higher levels, and the insoluble solids were decreased in all atmospheres with 2.4% O2. Appearance and concentrations of chlorophyll, soluble sugars, and proteins were maintained at 1C regardless of treatments.
Use of Stored Pollen to Hybridize a Mandarin Hybrid and Citrus tachibana
Authors: Niedz Randall P. , Bausher Michael G. , Hearn C. Jack
Published: February 2019

Fresh pollen from Citrus tachibana Macf. was oven-dried (37C), freeze-dried, or placed into anhydrous acetone, and stored at -20C over silica gel. Pollen freeze-dried or stored in anhydrous acetone did not germinate 24 hours after treatment; oven-dried pollen germinated in 1 hour and was comparable to fresh pollen. Pollen that was oven-dried for 12 hours and stored for 1 year was used to pollinate a monoembryonic hybrid of `Temple' (origin unknown) × `Orlando' (C. paradisi Macf. `Duncan' ×C. reticulata Blanco `Dancy'). Glutamate-oxaloacetate transaminase (GOT) isozyme profiles verified progeny hybridity.
Field Reaction of Landrace Components of Red Mottled Beans to Common Bacterial Blight
Authors: Beaver James S. , Steadman James R. , Coyne Dermot P.
Published: February 2019

Field reaction of 25 red mottled bean (Phaseolus vulgaris L.) genotypes to common bacterial blight [Xanthomonas campestris pv. phaseoli (Smith) Dye] was evaluated in Puerto Rico over 2 years. The average disease severity (percent leaf area with symptoms) was similar over years. The determinate red mottled genotypes had almost twice as much disease as indeterminate genotypes. Eight of the indeterminate genotypes had significantly less disease than the mean of the field experiments. These genotypes may serve as useful sources of resistance to common bacterial blight. The size of the chlorotic zone around necrotic lesions varied between growing seasons, showing that environment can influence the expression of common bacterial blight symptoms.
Origin of Walnut Somatic Embryos Determined by RFLP and Isozyme Analysis
Authors: Aly Mohammed A.M. , Fjellstrom Robert G. , McGranahan Gale H. , Parfitt Dan E.
Published: February 2019

Somatic embryos derived from walnut (Juglans regia L.) ovule tissues were evaluated to determine whether they were of zygotic or maternal origin. Molecular markers were used to permit evaluation at an early stage, before whole plant development. Somatic embryos developed from potentially apomictic `Sunland' and `Cisco' ovule tissue isolated from bagged putatively unpollinated flowers. Phosphoglucomutase (PGM) isozyme analysis showed that all of these embryos, except one from each cultivar, carry the same zymotype as the maternal tissue. However, restriction fragment length polymorphism (RPLP) analysis combined with isozyme evaluation demonstrated that the tested embryos originated from zygotic rather than maternal tissues. This study demonstrates the application of molecular marker analyses, particularly RFLPs, evaluation of somatic embryo origin.
Inherent Limitations of Nondestructive Chlorophyll Meters: A Comparison of Two Types of Meters
Authors: Monje Oscar A. , Bugbee Bruce
Published: February 2019

Two types of nondestructive chlorophyll meters were compared with a standard, destructive chlorophyll measurement technique. The nondestructive chlorophyll meters were 1) a custom built, single-wavelength meter, and 2) the recently introduced, dual-wavelength, chlorophyll meter from Minolta (model SPAD-502). Data from both meters were closely correlated with destructive measurements of chlorophyll (r2 = 0.90 and 0.93; respectively) for leaves with chlorophyll concentrations ranging from 100 to 600 mg·m-2, but both meters consistently overestimated chlorophyll outside this range. Although the dual-wavelength meter was slightly more accurate than the single-wavelength meter (higher r2), the light-scattering properties of leaf cells and the nonhomogeneous distribution of chlorophyll in leaves appear to limit the ability of all meters to estimate in vivo chlorophyll concentration.
A Pulsed Subirrigation System for Small Plots
Authors: Elliott George C.
Published: February 2019

A schematic diagram and parts list is presented for a simple and inexpensive system for pulsed subirrigation (commerically referred to as ebb and flow or flood and drain). The system can be readily modified for flowing solution culture. It has proven useful in teaching and research applications. It can be assembled from readily available parts using hand tools.
Priming Leek Seed for Improved Germination and Emergence at High Temperature
Authors: Parera Carlos A. , Cantliffe Daniel J.
Published: February 2019

`Verina' leek (AIlium porrum L.) seed germination is normally reduced at temperatures > 25C. Leek seeds were primed in aerated solutions (1.5 MPa, 10 days at 15C) of d-mannitol (mannitol), polyethylene glycol-8000 (PEG), KNO, and a nonaerated solution of PEG-8000 (PEG). At high temperatures mannitol, PEG, and PEG significantly enhanced germination percentage relative to KNO, or the control. At constant 30C, the mannitol, PEG, and PEG treatments increased final germination almost 10 times and the coefficient of velocity (COV) was improved compared to KNO, and the control. 10 growth chambers with alternating day/night temperatures (38 to 28C or 32 to 22C, 10 to 14 hours, respectively), primed seeds had significantly higher emergence and a larger COV than the control. In a greenhouse study under good conditions for germination, total emergence of primed and nonprimed seeds was similar; however, mannitol, PEG, and PEG led to a significantly higher COV than the control or KNO, treatments. These controlled-environment results demonstrate that priming leek seeds via mannitol, PEG, and PEG may promote early emergence at high temperature and improve stand uniformity for container transplant production.
Fewer Whiteflies Found on CO2-enriched Greenhouse Tomatoes with High C: N Ratios
Authors: Tripp Kim E. , Kroen William K. , Peet Mary M. , Willits Daniel H.
Published: February 2019

Eight tomato (Lycopersicon esculentum) cultivars were grown for 16 weeks in greenhouses enriched for an average of 8.1 hours daily to 1000 μl CO /liter of air or in greenhouses maintained at ambient CO. Carbon dioxide enrichment significantly decreased the mean number of greenhouse whiteflies [Trialeurodes vaporariorum (Westward), Homoptera: Aleyrodidae] as measured by counts from commercial yellow sticky traps. The number of whiteflies present was negatively correlated with both seasonal foliar C: N ratio and percent C but positively correlated with percent N in the foliage. Thus, CO enrichment apparently alters plant composition in such a way as to reduce significantly the population growth of greenhouse whiteflies.
Brief Extensions of Curing and Presprouting Increased Plant Production from Bedded Sweetpotato
Authors: Hall Melvin R.
Published: February 2019

`Georgia Jet' and `Jewel' sweetpotato (Ipomoea batatas L.) roots were cured (32 ±C lC, 85% ± 5% relative humidity (RH)] for 7 days immediately after harvest and then subjected to 0, 4, 8, or 12 additional days of curing before storage (16 ± lC, 85% ± 5% RI-I). Roots were presprouted (32 ± lC, 85% ± 5% RH) for 0, 4, 8, or 12 days before bedding. Plant emergence of `Georgia Jet' was accelerated with increasing duration of curing, but emergence of both cultivars was accelerated with increasing duration of short-interval presprouting. With increasing duration of extended curing, there was a nonlinear increase in the number of early and total `Georgia Jet' plants. However, with increasing duration of presprouting, there was a linear increase in the number of early and total plants of both cultivars. Average weights of early and total `Jewel' plants were higher than those of `Georgia Jet' plants. Treatments did not influence deterioration of bedded roots or the number of sprouts remaining on roots of a cultivar after 9 weeks of plant harvest. However, `Jewel' roots retained more sprouts than `Georgia Jet' roots, possibly indicating greater capacity for continued production of plants from `Jewel' than `Georgia Jet' if additional plant harvests were conducted.
Photoperiod and Gibberellic Acid Modify Growth and Flowering of Craspedia Globosa
Authors: Annis David C. , Gibson Paul T. , Starman Terri Woods
Published: February 2019

The objective of this study was to investigate the influence of photoperiod and 0, 1, 5, or 10 applications at weekly intervals of GA3 foliar sprays at 500 mg·liter–1 on growth and flowering of Craspedia globosa `Drumstick' Benth. Long days (LD) hastened flowering and increased the number of flowers per plant. Short days (SD) increased foliage height and foliage fresh and dry weights. Foliage and total plant heights increased and days to bud and secondary inflorescence width decreased linearly as GA3 application frequency increased. Chemical name used: (1α,2β,4aα,4bβ,10β)-2,4a,7-trihydroxy-1-methyl-8-methylen egibb-3-ene-1,10-dicarboxylic acid 1,4a-lactone (gibberellic acid, GA3).
Production of Somatic Hybrid and Autotetraploid Breeding Parents for Seedless Citrus Development
Authors: Grosser Jude W. , Gmitter Frederick G. , Louzada E.S. , Chandler J.L.
Published: February 2019

Allotetraploid somatic hybrid plants of `Nova' tangelo [a sexual hybrid of `Clementine mandarin (C. reticulata Blanco) × `Orlando' tangelo (C. reticulata × C. paradisi Macf.)] + `Succari' sweet orange (C. sinensis L. Osbeck), and `Hamlin' sweet orange (C. sinensis L. Osbeck) + `Dancy' tangerine (C. reticulata) were regenerated following protoplast fusion. `Nova' and `Hamlin' protoplasts were isolated from ovule-derived embryogenic callus and suspension cultures, respectively, and fused using a polyethylene glycol method with seedling leaf-derived protoplasts of `Succari' and `Dancy', respectively. Plants were regenerated via somatic embryogenesis, and somatic hybrids were identified on the basis of leaf morphology, root-tip cell chromosome number, and electrophoretic analysis of peroxidase and phosphoglucose mutase isozyme banding patterns. Diploid plants were regenerated from unfused protoplasts of `Hamlin', `Nova', and `Succari'. Tetraploid plants of `Hamlin' and `Succari' were also recovered, apparently resulting from homokaryotic fusions. No `Dancy' plants were recovered. The somatic hybrid and autotetraploid plants can be used for interploid hybridization with selected monoembryonic scions to generate improved seedless triploid tangor/tangelo cultivars. The lack of suitable tetraploid breeding parents has previously inhibited the development of quality seedless cultivars by this method.
Use of a Cytokinin Conjugate for Efficient Shoot Regeneration from Leaf Sections of Highbush Blueberry
Authors: Rowland Lisa J. , Ogden Elizabeth L.
Published: February 2019

Conditions for improving the efficiency of shoot regeneration from leaf sections of highbush blueberry (Vaccinium corymbosum L.) were investigated. Effectiveness of tissue culture medium supplemented with the cytokinin conjugate zeatin riboside or the cytokinin zeatin at 10, 20, or 30 μm was compared with medium supplemented with the optimum 2iP concentration of 15 μm. Use of 20 μm zeatin riboside resulted in the most shoots per leaf section, » 6-fold higher than the number of shoots produced on 2iP medium. The number of shoots produced on medium supplemented with zeatin was not significantly higher than the number of shoots produced on 2iP medium. Consequently, we concluded that the cytokinin conjugate zeatin riboside was more effective than either of the free cytokinins, 2iP or zeatin, in promoting shoot regeneration from leaf sections of highbush blueberry. Chemical names used: 6-(y,y-dimethylallylamino)-purine (2iP); 6-(4-hydroxy-3-methyl-but-2-enylamino)purine (zeatin).
GROUND STEMS OF KENAF (Hibiscus cannabinus L.) AS A BULKING COMPONENT IN GREENHOUSE GROWTH MEDIA
Authors: Pill Wallace , Shi Bing
Published: February 2019

Kenaf stems were ground and sieved to yield fine (<2mm), medium (2 to 6 mm) or coarse (6 to 12 mm) grades. These grades were mixed at 25, 50 or 75% volumes in sphagnum peatmoss and then provided standard basal fertilization. Tomato and impatiens shoot fresh weights 4 weeks after transplanting (50 mg N.liter-1 daily liquid feed) were greatest in 25% medium kenaf, being 68 and 89%, respectively, those in peat-lite (ProMix BX). In a further study, medium kenaf was soaked for 3 days in 5000, 10000 or 15000 mg N.liter-1 from 20N-4. 3P-8.6K then mixed at 25% volume in peatmoss. Tomato seedlings transplanted into these media were provided 0, 100, 300 or 500 mg N.liter-1 daily liquid feed (LF) from 20N-4.3P-8.6K. With ≥100 mg N.liter-1 LF, soak solution concentration had no effect on shoot fresh weight. With 0 mg N.liter-1 LF however, kenaf media soaked in 10000 or 15000 mg N.liter-1 yielded greater shoot fresh weights than ProMix with 100 mg N.liter-1, LF.
MINERAL NUTRITION OF RED SPRUCE SEEDLINGS IN AN ACIDIC FOREST SOIL
Authors: Hoelldampf Baerbel , Barker Allen V
Published: February 2019

Coniferous forest trees showing chlorosis and dieback appear to be deficient in Ca and Mg. These deficiencies may be induced by nitrogenous nutrients borne in the atmosphere. This study assessed the roles of nitrogen nutrition and soil on nutrient accumulation by red spruce (Picea rubens, Sarg.) and radishes (Raphanus sativus, L.). Plants were grown in the greenhouse in acid O or A horizons (Typic Haplorthod) collected from a red spruce forest. Plants were grown with a complete nutrient solution with 15 mM N of which NH4 was 0, 3.75, 7.5, 11.25, or 15 mM with the remainder being NO3-. After 120 days, the spruce needles became chlorotic with 11.25 or 15 mM NH4. Radishes exhibited NH4-toxicity after 28 days. Radishes were larger in the O horizon than in the A horizon. As NH4 was increased, radishes had lesser dry weights and accumulated less foliar Ca. Foliar Ca also was lower in spruce with the higher NH4. Magnesium concentrations in leaves of red spruce and radishes were not affected significantly by increasing NH4 supply. Radishes are suitable indicator plants to study the effect of nitrogen form on mineral nutrition of spruce because each species responded similarly to the treatments.
STRAWBERRY FRUIT MALFORMATION AS A RESULT OF FROST INJURY
Authors: Handley David T.
Published: February 2019

Frost injury on strawberry flowers (cv. Redchief) was studied in a field over two seasons. During the first season, a light frost during anthesis caused varying degrees of injury to blossoms. Five grades were assigned to the blossoms according to the degree of injury observed. The resulting fruit malformations correlated to the severity of blossom injury, ranging from no development (blossom death) when flower receptacles were completely black, to slight dimpling when only a portion of the receptacle had been discolored. During the second season, a colder frost occurring at the bud stage caused generally greater injury to the blossoms. The range of injury was less variable, therefore only three grades were assigned to the blossoms. The resulting fruit malformation again related to the intensity of blossom injury. Frost has long been understood to kill unprotected strawberry blossoms. This study has shown that nonfatal frost injury to strawberry blossoms can result in a variety of fruit malformations which previously may have been attributed to other causes.
INFLUENCE OF CULTIVAR, PLANTING TECHNIQUE AND HARVEST DURATION ON ASPARAGUS YIELD
Authors: Wilcox-Lee Darlene , Drost Daniel T.
Published: February 2019

Crowns and tranplants of `Martha Washington' (MW) and `Jersey Prince' (JP) asparagus were planted in 1985. Plots were harvested for 0,2,4 weeks (traditional schedule); 1,2,6 weeks (moderate harvest pressure); or 2,4,8 weeks (severe harvest pressure) in 1986, 1987, and 1988, respectively. All plots were harvested for 8 weeks after 1988. An AOV was performed to test the main effects of cv, planting technique and harvest schedules and interactions on early and total season yield of large, medium-sized and total spears. MW produced a significantly higher yield of both early and total season large spears than JP in all years. Total yields did not differ between cvs. There was no significant effect of planting technique on yield in any year. Harvest schedules imposed in the first 3 years had significant long term effects on yield. Although severe harvest pressure produced larger yields than the other schedules in 1986-1988, from 1989-1991 yields were lowest in the severe harvest pressure plots. The traditional harvest schedule produced similar yields to the moderate pressure schedule. There were no consistent interactions between cultivar, planting technique and harvest schedule These data indicate that a slightly more aggressive harvest schedule in the early years of an asparagus planting would not have long term deterimental effect on yield. However, severe cutting pressure can reduce yields compared to traditional cutting schedules for at least 3 years after initial harvest pressure treatment
GA4 AND GA7 INFLUENCE FLOWER BUD FORMATION AND RUSSET DEVELOPMENT ON APPLE
Authors: Greene Duane W.
Published: February 2019

GA4+7 and GA4 substantially reduced russeting of `Golden Delicious' in four different years. There were indications that GA4 was more effective than GA4+7 at reducing russeting. The influence of gibberellins on flowering was variable and not always related to crop load. GA4 increased flowering in one experiment, had no influence in two experiments, and inhibited flowering in two experiments. GA7 either inhibited flowering or had no effect. There were indications that GA4 may partially reverse the inhibitory effect of GA7 on flowering in some instances.
FALL FRUITING RASPBERRY PRODUCTION UNDER PLASTIC TUNNELS
Authors: Lamarre Michel , Lareau Michel J.
Published: February 2019

From 1988 to 1990, the fall fruiting raspberries Heritage, Perron Red, Autumn Bliss and 3413-12 were field evaluated under two cultural systems: conventionnal production and production under plastic tunnel. The plastic tunnel was in place over 4 rows from early September to late October without supplemental heating. Compared to the conventionnal system, the tunnel contributed to a lengthening of 1 to 4 weeks in the fruiting period 2 years out of 3. In spite of the higher day temperatures, the rate of fruit ripening was not increased under the tunnel but fruit size was increased slightly. However, the latter did not translate in higher yield per day since fruit number decreased under the tunnel. Total yield increased only one year when the first killing frost occurred a full month before the second one. Generally, night temperatures were as low in the tunnel as those outside.
INTEGRATED MANAGEMENT OF WEEDS IN A PERENNIAL CROP:THE EXAMPLE OF CRANBERRIES
Authors: Else M.J.
Published: February 2019

In Integrated Pest Management (IPM), the costs of a control measure are compared to the potential for economic losses caused by a pest, with control measures being recommended only when expected costs of losses exceed costs of control. IPM models have been developed largely for insect pests, which multiply rapidly and for which timely population assessments are thus essential. Weed pests, on the other hand, multiply slowly. In the case of perennial crops, weeds may not reach populations sufficient to warrant control under conventional IPM criteria for many years. It is proposed that IPM concepts be adapted to weedy pests of perennial crops by creating models in which the long-term costs and consequences of both weeds and weed control measures are considered. These models would take into account expected increases in control costs and decreases in effectiveness of control measures over time and as a consequence consider some weeds to have effective thresholds at or near zero.
EFFECTS OF FIBROUS ROOT INFECTION BY STREPTOMYCES IPOMOEA ON YIELD OF SWEETPOTATO.
Authors: Ristaino Jean B. , Averre Charles
Published: February 2019

The effect of fibrous root infection by S. ipomoea on disease on storage roots and production of marketable yield in the susceptible sweetpotato cultivar `Jewel' was evaluated in field experiments in 3 years. Drip irrigation (main plots) reduced disease on fibrous roots in plots not treated with sulfur or fumigated, but did not significantly increase yields in any year. Sulfur (subplots) reduced the severity of the disease on fibrous roots in nonfumigated plots in 2 years, but reduced yields by 21-33% in 2 of 3 years. Fumigation of soil with Telone C-17 (sub-subplots) reduced the percentage of diseased storage roots produced per plot from 71%, 8%, and 22% in nonfumigated plots to 52%, 3% and 6% in fumigated plots in 1988, 1989 and 1990, respectively and reduced the severity of disease on fibrous roots in all years. Only fumigation increased the yield of marketable storage roots by 68% and 19% in two of three years. The severity of disease on fibrous roots was positively correlated with the percentage of diseased storage roots produced per plot (r = 0.84) and the number of diseased storage roots produced per plant (r = 0.64), and was negatively correlated with the number of storage roots produced per plant (r = -0.66). Yield of marketable storage roots was negatively correlated with both the severity of disease on fibrous roots (r = -0.77) and the percentage of diseased storage roots produced per plot (r = -0.73). These data demonstrate the importance of fibrous root disease in this pathosystem. Management strategies that reduce disease on fibrous roots may ultimately lead to increased yield of storage roots.
AN INTEGRATED PEST MANAGEMENT EXTENSION PROGRAM FOR NURSERY PRODUCERS IN SOUTH CAROLINA
Authors: Moody J.T. , Halbrooks M.C.
Published: February 2019

The ornamental horticulture industry in South Carolina has expanded significantly over the last decade. Today, concerns regarding environmental and public health, and stricter regulations of pesticide use, are creating incentives for growers to evaluate alternative methods of pest control. Nursery producers currently use an array of chemicals in an attempt to control pests including insects, weeds, and diseases. Integrated pest management (IPM) provides an opportunity to reduce chemical reliance. The overall objective of this extension program is to collect and collate information relevant to the implementation of an IPM program. The first year, 1989-90, surveys were developed to determine key factors related nursery pest management. Types of data collected included: key pest species; pest-plant relationships; grower action responses to pest problems; types and frequency of pesticide use. The second year, 1990-91, involved implementing IPM strategies such as: cultural methods; use of horticultural oils, soaps, and lower risk pesticides; and spot treatment applications to help maintain pest populations below economically damaging levels. Improvements in pest management included; reduced chemical applications, reduced associated environmental risks, and maintenance of aesthetic quality of plants.
CHANGES IN ORGANIC ACIDS AND OTHER COMPOSITIONAL AND PHYSIOLOGICAL ATTRIBUTES OF PEACHES DUE TO CHILLING INJURY.
Authors: Wang T. , Gonzalez A. R. , Gbur E. E. , Aselage J. M.
Published: February 2019

Babygold 5 (BG5) and Redhaven (RDH) peaches at maturity 4 were held at 2.3°C for 0, 2 and 4 weeks. After each cold storage treatment half of the fruit sample was evaluated; the other half was ripened for 8 days at 21°C and respiration was measured daily. The evaluations on both samples were for malic, citric and quinic acids, titratable acidity (TA), soluble solids (SS) and flesh firmness. Malic acid in ripened BG5 and RDH Fruits increased relative to their unripened counterpart over the cold storage time; citric acid increased in BG5, decreased in RDH; quinic acid decreased in both cultivars; TA increased; SS decreased in BG5, did not change in RDH; flesh firmness increased in BG5, did not change in RDH. Respiratory rate increased with cold storge time in both cultivars. Overall, BG5 showed more susceptibility to chilling than RDH.
EFFECT OF VARIOUS METHODS OF PACLOBUTRAZOL APPLICATION ON CHERRY TREE PERFORMANCE AND SOIL RESIDUE.
Authors: Jacyna T. , Dodds K.G.
Published: February 2019

Four-year old sweet cherry trees of cv. Bing growing in HDP(1481 trees/ha) were treated with paclobutrazol(PBZ) as trunk drench(T), shank(S) and paint(P) application at standart rate 15 mg PBZ/cm2 of trunk cross sectional area. All chemical treatments caused a significant reduction in total extension growth and shoot length as compared with the control. No significant differences in yield, fruit firmness, % soluble solids, fruit stalk length and fruit weight between the treatments were found. 18 months after PBZ application in the orchard, the PBZ soil residue was assessed by means of bioassay. Indicator plant produced 23.6, 56.1 and 70.5 percent of control growth when grown in the soil taken from T, S and P, respectively. P and S were able to significantly reduce PBZ soil residue without decreasing the effectiveness of PBZ and any adverse effects on fruit yield and quality.
SOIL INJECTION OF BAS 111-06W REDUCES SHOOT GROWTH IN PEACH
Authors: Reighard Gregory L.
Published: February 2019

The growth regulator BAS 111-06W was applied twice each spring for 3 years to 5-year-old 'Loring' trees. First year treatments were foliar sprays (1 or 2 g a.i.), trunk paints (2 or 4 g a.i.), and soil shank injections (2 or 4 g a.i.). Foliar treated trees developed severe leaf shotholing or bacteriosis. Shank treatments were the most effective in controlling shoot growth. Thus, second and third year treatments consisted only of the shank applications. Both the 2 and 4 g rates were equally effective in reducing shoot elongation 10-34% annually. Treated trees bloomed 1-2 days earlier and had shorter bloom periods than the controls. Flower bud density and flower number were greater on treated trees. Fruit yields were not affected. Treated trees required less summer and corrective winter pruning, but had more short shoots to thin out.
INTERACTION OF TRAINING SYSTEM, SUMMER PRUNING AND ROOT PRUNING ON YIELD AND CANOPY DENSITY OF PEACH
Authors: Olien W.C. , Williamson R.E. , Hood C.E. , Decoteau D.R. , Coston D.C.
Published: February 2019

Factorial combinations of ± root pruning (RP) and ± summer pruning (SP) were initiated in 1991 as subplots within a Redhaven/Lovell study of orchard training systems: Open Center (OC), Y-Trellis (YT), Central Leader (CL), and Meadow Orchard (MO) established in 1985. Root pruning was imposed at bloom (March 28) at 76 cm from the trunk to a depth of 45 cm. Summer pruning consisted of preharvest removal of water sprouts (June 5). Canopy density, quantified by transmittance of PAR radiation through the canopy, was greatest in OC and MO and least in YT and CL systems. SP and RP treatments further reduced canopy density by 35 to 80%. There were no main or interactive effects of SP and RP on 1991 yields or fruit quality, and also no interactive effects of orchard systems with SP and RP. Thus, SP and RP reduced canopy density without negative effects on fruit. RP, however, advanced harvest date by ca 4 days. A parallel study was also initiated in 1991 to determine the effects of root pruning distance (30, 60, 90 cm from the trunk, or no RP) on canopy density, yield, and fruit quality of mature, OC-trained Redhaven/ and Jefferson/Lovell. Reduction in canopy density without loss of yield or fruit size was obtained at a RP distance between 60 and 90 cm.
COMPARISON OF INTEGRATED CROP MANAGEMENT AND A SCHEDULED PREVENTATIVE PEST CONTROL PROGRAM IN A COMMERCIAL APPLE ORCHARD
Authors: Brown Gerald , Bessin Ricardo , Hartman John , Wolfe Dwight , Strang John
Published: February 2019

Apple growers in Kentucky normally control pests on a preventative schedule involving fifteen or more chemical applications annually. IPM technology designed to provide growers information about the threat of diseases and insects was used in a demonstration plot in a Daviess County orchard and in the U.K. research orchard, Princeton. The IPM systems used in Daviess County resulted in 6 less applications of pesticides than the traditional system, a savings of approximately $130 per acre. When compared to the traditional preventative spray schedule, the IPM treated apples showed no differences in fruit quality and in orchard diseases and insect infestations. The decreased pesticide use has the potential to reduce applicator exposure, residues on fruit, and the environmental impact of these chemicals. The results of this demonstration were shared with and received an enthusiastic response from growers, Extension personnel, students, consumers, and the news media. The project demonstrated the feasibility of using apple IPM by a Kentucky grower, and it provided students an insight into applied biology.
INFLUENCE OF ROW TUNNELS ON POTATO PRODUCTION IN MISSOURI
Authors: Wilson Mack A. , Kahn Victor A.
Published: February 2019

Four row covers (clear and white slitted), spunbonded polyester, and VisPore were used on `Atlantic' potato cultivar at Charleston, Missouri. Row covers were installed on March 6, 1991 and removed on May 5, 1991. No significant differences were observed with orthoganal comparisons on grade A, B, and total number of potatoes among row covers. Total yields were higher with row covers and the data was significant. Potato plant heights were greater with row covers and the data was significantly different when the control was compared with row covers.
EVALUATION OF WESTERN SHIPPER MELONS GROWN IN FLORIDA
Authors: Elmstrom Gary W. , Maynard Donald N.
Published: February 2019

Muskmelon (Cucumis melo L. reticulatus group), commonly called cantaloupe by growers, shippers, and consumers is a relatively minor crop in the southeastern U.S. The principal restraint on increased muskmelon production in this area is the lack of varieties that consistently produce high quality fruit. Resistance to both fruit rots, especially those induced by Fusarium, and foliar diseases such as downy mildew, powdery mildew, and gummy stem blight are also important because of the high humidity and frequent rainfall common to this area. The ideal shipping variety should have the capacity to produce high yields of round to oval, sutureless, heavily netted fruit that average 1.4 kg each, and that have a deep salmon-colored flesh, a small tight seed cavity, high soluble solids, and a pleasant taste and aroma. Evaluations at Leesburg and Bradenton, Florida over a three-year period have identified several western-type muskmelons well-adapted to this area. `Explorer', `Goldmark', `Mission', and `Tasty Sweet' ranked high in most of the categories mentioned above and should be evaluated in more extensive trials, which should include a study of postharvest quality.