bluuebunny/crossref_metadata_2025 huggingface dataset:
High Zinc Concentrations in the Growing Medium Contribute to Chlorosis in Blueberry
Authors: Gupton Creighton L. , Spiers James M.
Published: February 2019

An experiment arranged in a randomized complete block design with four replications of two cultivars × six pH levels × four Zn levels was conducted to determine if Zn caused leaf chlorosis in rabbiteye (Vaccinium ashei Reade cv. Climax) and southern highbush (mostly V. corymbosum L. cv. Bladen) blueberry. `Bladen' accumulated more foliar Mn and Zn than `Climax', but Fe concentration was similar in the two cultivars. Leaf chlorosis ratings were similar for the two cultivars. Solution pH had no significant effect on Mn, Zn, or Fe leaf concentration or degree of chlorosis. Zinc level in the nutrient solution affected leaf concentration of Mn and Zn but not of Fe. A significant linear increase in chlorosis resulted from increasing Zn solution concentration from 30 to 120 mg·L–1. We conclude that high levels of Zn may induce leaf chlorosis in rabbiteye and southern highbush blueberry.
Paper Sludge Amendments for Turfgrass
Authors: Norrie J. , Gosselin A.
Published: February 2019

The behavior of turfgrass grown on paper-sludge-amended soils was evaluated over 2 years. Two experiments were performed, one with deinked sludge and another with primary sludge. Four paper sludge, sand, and organic soil substrate mixtures with proportions ranging from 0% to 50% paper sludge were incorporated into existing soils. Two fertilization levels were applied in strip plots across sludge treatments and three turfgrasses of seeded Kentucky bluegrass (Poa pratensis L. `Georgetown'), Kentucky bluegrass sod, and an 80 Kentucky bluegrass: 20 perennial ryegrass (Lolium perenne L. `Prelude') seed mix were arranged within split plots. Effects of deinked and primary sludge experiments were similar. Supplemental N and, to a lesser degree, P and K fertilization with N at ≈4.5 to 5.5 t·ha–1, P at 1.18 to 1.26 t·ha–1, and K at 1.34 to 1.46 t·ha–1 improved ground cover, turf color, and stand quality. Despite differences in visual evaluations, leaf mineral nutrition was only slightly affected by fertilization treatments. Soil in nonfertilized plots was several times lower in N-NO3 when compared to fertilized plots, regardless of sludge rate. Soil in fertilized plots had higher concentrations of inorganic N regardless of sludge amendment. The soil C: N ratio was ≈13:1 in nonamended plots and more than 15:1 under the highest sludge rate. Deinked and primary paper sludges can be used effectively as soil amendments if turfgrass receives adequate supplemental N, P, and K.
Suitability of Composted Green Waste for Horticultural Uses
Authors: Hartz T.K. , Costa F.J. , Schrader W.L.
Published: February 2019

The study was undertaken to determine the physiochemical properties and nutrient supply characteristics of composted green yard and landscape waste (CGW) and to document its performance as a field soil amendment or constituent of potting media. Three CGW samples were collected from each of two composting operations in California from Nov. 1993 to Apr. 1994. Macronutrient content varied widely between operations, and among samples from the same operation, with mean total N, P, and K levels averaging 1.1%, 0.26%, and 0.67%, respectively. Controlled-environment incubation of a moist 1 CGW: 9 soil blend (2 weeks at 30 °C) was conducted to determine net N mineralization from CGW. Despite low C: N ratios (<12), five of six CGW samples showed net immobilization, a characteristic of immature compost. An in-field incubation of soil amended with 1% or 2% CGW (w/w) showed no net N release from CGW over 4 months. In a field trial, bell pepper (Capsicum annuum L.) fruit yield was increased by soil amendment with CGW (17 or 34 t·ha–1) under a low N fertilizer regime (168 kg·ha–1), but was unaffected where sufficient fertilizer N (280 kg·ha–1) was applied. CGW was compared with peat as a constituent of potting media; both were blended 1:1 (v/v) with perlite and used in the production of tomato (Lycopersicon esculentum Mill.) and marigold (Tagetes erecta L.) plants under varying fertigation regimes (constant feed of N at 0, 50, or 100 mg·L–1 as 15N–13P–12K). CGW was equivalent or superior to peat in plant growth; CGW did contribute to crop macronutrient nutrition, but the highest fertigation rate was required for optimum growth.
Zoysiagrass Establishment from Sprigs following Application of Herbicides, Nitrogen, and a Biostimulator
Authors: Carroll M.J. , Dernoeden P.H. , Krouse J.M.
Published: February 2019

Sprigs of `Meyer' zoysiagrass (Zoysia japonica Steud.) were treated with urea nitrogen, a biostimulator, and one of three preemergence herbicides or one of two postemergence herbicides to hasten establishment in two field studies. Monthly application of N at 48 kg·ha–1 during the growing season had no influence on sprig establishment the first year, but slightly increased (+5%) zoysiagrass cover the second year. Presoaking sprigs in a solution containing (mg·L–1) 173 auxin and 81 cytokinin, and iron at 1.25 g·L–1 before broadcasting of sprigs, and biweekly sprays (g·ha–1) of 53 auxin and 24 cytokinin, and iron at 0.2 g·L–1 or (g·ha–1) 68 auxin and 36 cytokinin, and iron at 1.45 g·L–1 after broadcasting sprigs had no effect on zoysiagrass cover or rooting. Preemergence and postemergence herbicide use generally enhanced zoysiagrass cover by reducing smooth crabgrass competition [Digitaria ischaemum (Schreb. ex Schweig) Schreb. ex Muhl]. Oxadiazon enhanced zoysiagrass coverage more than dithiopyr, pendimethalin, quinclorac, or fenoxaprop. Oxadiazon and dithiopyr provided similar levels of crabgrass control, but dithiopyr reduced `Meyer' zoysiagrass midsummer root growth. Chemical names used: 3,5,-pyridinedicarbothioic acid, 2-[difluromethyl]-4-[2-methyl-propyl]-6-(trifluoromethyl)-S,S-dimethyl ester (dithiopyr); [±]-ethyl 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy] propanoate (fenoxaprop); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); 3,7-dichloro-8-quin-olinecarboxylic acid (quinclorac).
Enhancement of Snap Bean Emergence by Gliocladium virens
Authors: Smith V.L.
Published: February 2019

Emergence of snap beans (Phaseolus vulgaris L.) in field soil in 1993–95 was enhanced by the biocontrol agent Gliocladium virens J.H. Miller, J.E. Giddens, & A.A. Foster. The fungus was applied to each seed at planting as a wheat bran alginate pellet formulation in 1993–95. Preemergence and postemergence damping-off were reduced in plots treated with G. virens. Nodulation on the roots of treated plants was numerically increased in 1993 and 1994 compared to nontreated plots. Efficacy of G. virens was reduced in 1995, probably due to high ambient temperatures at the time of planting. In plots with reduced stand, leaf area was increased and yield on a per-plant basis was larger than in plots with a better stand. Total yield also was increased in plots with fewer plants, except in 1994. Fungi isolated from failed seedlings included Fusarium spp., Pythium spp., and Rhizoctonia solani Kühn.
Fruit Pigmentation of Four Green Apple Cultivars Responds to Urea Sprays but not to Nitrogen Fertilization
Authors: Meheriuk M. , McKenzie D.-L. , Neilsen G.H. , Hall J.W.
Published: February 2019

Four green apple (Malus domestica Borkh.) cultivars, `Granny Smith', `Mutsu', `Newtown', and `Shamrock', were subjected to a factorial experiment of two rates of nitrogen fertilization and three concentrations of foliar urea sprays for 4 years. The higher rate of N (160 kg N/ha) had no effect on ground color or fruit quality relative to the lower rate of 80 kg N/ha. Urea sprays enhanced green pigmentation in `Granny Smith' and `Newtown' at harvest and retarded yellowing of fruit in all cultivars during air storage at 0C. Response was similar for urea at 0.5% and 1%, and urea sprays did not adversely affect quality. Urea sprays increased fruit N by 23% and 47% for the 0.5% and 1% concentrations, respectively.
Interseeding Legumes into Chile: Legume Productivity and Effect on Chile Yield
Authors: Guldan Steven J. , Martin Charles A. , Cueto-Wong Jose , Steiner Robert L.
Published: February 2019

Three legumes [hairy vetch (Vicia villosa Roth.), barrel medic (Medicago truncatula Gaerth.), and black lentil (Lens culinaris Medik.)] were interseeded into `New Mexico 6-4' chile pepper (Capsicum annuum L.) when plants were 20–30 cm tall (3 Aug., “early” interseeding) or when plants were 30–40 cm tall (16–17 Aug., “late” interseeding) in 1993 and 1994. Our objectives were to determine the effect of legume interseeding on cumulative chile yield, and late-season dry-matter and nitrogen yields of aboveground portions of the legumes. Legumes were harvested on 8 Nov. 1993 and 15 Nov. 1994. Chile yield was not significantly affected by legume interseeding. In 1993, legumes accumulated 57% more dry matter and 55% more N when interseeded 3 Aug. vs. 16 Aug. In 1994, legumes accumulated 91% more dry matter and 86% more N when interseeded 3 Aug. vs. 17 Aug. Aboveground dry-matter yields in 1993 ranged from 1350 kg·ha–1 for black lentil interseeded late to 3370 kg·ha–1 for hairy vetch interseeded early. Nitrogen yields ranged from 52 kg·ha–1 for black lentil interseeded late to 136 kg·ha–1 for hairy vetch interseeded early. In 1994, hairy vetch was the highest yielding legume with dry matter at 1810 kg·ha–1 and N at 56 kg·ha–1 interseeded early, while black lentil yielded the lowest with dry matter at 504 kg·ha–1 and N at 17 kg·ha–1 interseeded late. In the spring following each interseeding year, we observed that hairy vetch had overwintered well, whereas barrel medic and black lentil had not, except when a few plants of barrel medic survived the winter of 1994–95. Results from this study indicate that legumes can be successfully interseeded into chile in the high-desert region of the southwestern United States without a significant decrease in chile yield.
Salinity Affects Growth, Yield and Elemental Concentration of Fennel
Authors: Graifenberg A. , Botrini L. , Giustiniani L. , Di Paola M. Lipucci
Published: February 2019

`Monte Bianco' and `Everest' fennel (Foeniculum vulgare Mill.) were grown in 157-L plastic pots and irrigated with water containing NaCl at 0, 0.25, 0.5, 1.0, 1.5, 2.0, or 2.5 g·L–1. The salt-tolerance threshold for yield was expressed as electrical conductivity of irrigation water (ECi) and saturated soil extract (ECe). ECi was 1.15 dS·m–1 for both cultivars and ECe was 1.51 and 1.47 dS·m–1 for `Monte Bianco' and `Everest', respectively. The thresholds for plant fresh weight were the same as yield. Below the threshold the average bulb yields were 265 g/plant in `Monte Bianco' and 284 g/plant in `Everest'. Relative yields were reduced 18.9% and 17.8% for ECi and 15.7% and 14.3% for ECe for each unit increase above the threshold in `Monte Bianco' and `Everest', respectively. Sodium concentration was higher in bulbs in comparison with other tissues at all salinities. Bulb Na concentration increased to 3 dS·m–1, reaching 1835 and 1866 mmol·kg–1 dry weight in `Monte Bianco' and `Everest', respectively. Chloride concentration had similar tissue distribution and trend as Na. Potassium concentration in bulbs decreased with increasing Na concentration, while it remained constant in the other organs. Calcium concentration was not affected by salinity. Thus, fennel is sensitive to salt stress, lacking mechanisms for controlling ion influx into plant tissues, and is unable to cope with saline sodic environments.
In Vitro Rooting and Greenhouse Acclimatization of Veltheimia bracteata and V. capensis Shoots
Authors: Ault James R.
Published: February 2019

Shoot initiation and multiplication were obtained in vitro from immature flower bud and leaf explants of Veltheimia bracteata Bak. `Lemon Flame' and from leaf explants of V. bracteata `Rosalba' cultured on a Murashige and Skoog (MS) medium supplemented with sucrose at 30 g•L–1, and either 8.87 μm BA plus 0.54 μm NAA or 8.87 μm BA plus 5.40 μm NAA. Shoot initiation and multiplication was obtained from a single leaf explant of Veltheimia capensis (L.) DC. on MS medium with 8.87 μm BA plus 0.54 μm NAA. Shoots of the three genotypes rooted on subculture to medium with 0.0, 4.14, or 8.29 μm K-IBA or 0.0, 4.46, or 8.92 μm K-NAA. Maximal rooting was 98% for V. bracteata `Lemon Flame', 95% for V. bracteata `Rosalba', and 98% for V. capensis, from medium with 4.46 μm KNAA. Rooted shoots were acclimatized for 3 to 4 weeks. Overall survival percentage was 69% for V. bracteata `Lemon Flame', 65% for V. bracteata `Rosalba', and 83% for V. capensis. Chemical names used: 6-benzyladenine (BA); potassium salt of indole-3-butyric acid (K-IBA); potassium salt of 1-naphthaleneacetic acid (K-NAA); 1-naphthaleneacetic acid (NAA).
Water Loss and Survival of Stem Cuttings of Two Maple Cultivars Held in Subirrigated Medium at 24 to 33 °C
Authors: Zhang Hongyi , Graves William R. , Townsend Alden M.
Published: February 2019

We determined transpiration rate, survival, and rooting of unmisted, softwood cuttings of `Autumn Flame' red maple (Acer rubrum L.) and `Indian Summer' Freeman maple (Acer ×freemanii E. Murray). Effects of perlite at 24, 30, and 33 °C were assessed to determine whether responses of cuttings would be consistent with cultivar differences in resistance to root-zone heat previously shown with whole plants. During 7 d, cutting fresh mass increased by ≈20% at all temperatures for `Autumn Flame' red maple, but fresh mass of `Indian Summer' Freeman maple decreased by 17% and 21% at 30 and 33 °C, respectively. The percentage of cuttings of `Indian Summer' that were alive decreased over time and with increasing temperature. Transpiration rate decreased during the first half of the treatment period and then increased to ≈1.1 and 0.3 mmol·m-2·s-1 for `Autumn Flame' and `Indian Summer', respectively. Mean rooting percentages over temperatures for `Autumn Flame' and `Indian Summer' were 69 % and 16%, respectively. Mean rooting percentages at 24, 30, and 33 °C over both cultivars were 74%, 29%, and 25%, respectively. Over temperatures, mean root count per cutting was 41 and seven, and mean root dry mass per cutting was 4.9 and 0.4 mg, for `Autumn Flame' and `Indian Summer', respectively. Use of subirrigation without mist to root stem cuttings was more successful for `Autumn Flame' than for `Indian Summer'. Temperature × cultivar interactions for cutting fresh mass and the percentage of cuttings remaining alive during treatment were consistent with previous evidence that whole plants of `Autumn Flame' are more heat resistant than plants of `Indian Summer'. Mass and survival of stem cuttings during propagation in heated rooting medium may serve as tools for screening for whole-plant heat resistance among maple genotypes.
Shade Influences Plant Growth, Leaf Color, and Chlorophyll Content of Kalmia latifolia L. Cultivars
Authors: Brand Mark H.
Published: February 2019

The effect of shading during nursery production on the growth, foliage color, and foliar chlorophyll content of container-grown Kalmia latifolia cultivars was investigated. Five cultivars were grown under 40% shade, 60% shade, or full sunlight for a 2-year production cycle. During the first year of production, there were no significant differences in measured growth characteristics for most cultivars in response to light treatment. Shade improved foliar color by decreasing lightness (L*), decreasing chroma, and changing hue angle from a yellow-green to a darker green. Foliar chlorophyll concentration increased under shade. In the second year of the production cycle, the response of foliar color and chlorophyll concentration to shade was similar to that observed in year 1. Plant size, number of branches, leaf area, leaf dry mass, and stem dry mass decreased linearly with increasing shade in year 2. Although shading improves foliar color, it probably should not be employed for container production of Kalmia latifolia in cool, northern production areas due to reduced plant growth during year 2. Shade may be useful in the first year of production to enhance foliar color without reducing shoot growth.
Supplemental Light before Harvest Increases Phenethyl Isothiocyanate in Watercress under 8-hour Photoperiod
Authors: Palaniswamy Usha , McAvoy Richard , Bible Bernard
Published: February 2019

Watercress (Nasturtium officinale R.Br.) plants were grown in growth chambers at 15 °C or 25 °C and either 8- or 12-h photoperiod (PP). The photosynthetic photon flux (PPF) was 265 μmol·m-2s-1 in all chambers, but beginning 1 week before harvest, half of the plants in each chamber were subjected to a higher PPF (435 μmol·m-2·s-1). At harvest, watercress leaves and stems were analyzed for phenethyl isothiocyanate (PEITC) concentration. Without supplemental PPF, watercress grown at 25 °C and 12-h PP produced higher PEITC concentration in leaves and stems than plants grown at 15 °C and 12-h PP, or plants grown at 8-h PP and either temperature. With one week of supplemental PPF before harvest, plants grown at 15 or 25 °C and the 8-h PP produced PEITC concentrations as high as plants exposed to 12-h PP and similar temperatures. However, a week of supplemental PPF did not alter PEITC concentrations in plants grown at the 12-h PP, regardless of temperature. At 25 °C, plants grown under the low PPF and the 12-h PP produced 62% greater dry mass than plants exposed to a week of high PPF and the 8-h PP, but did not differ in PEITC content. Thus, the effect of one week of high PPF on PEITC concentration depended on photoperiod.
Increased Yield of Heat-tolerant Tomatoes with Deep Transplanting, Morning Irrigation, and White Mulch
Authors: Hanna H.Y. , Millhollon E.P. , Herrick J.K. , Fletcher C.L.
Published: February 2019

Studies were conducted in Fall 1994 and Summer 1995 to determine growth and yield response of heat-tolerant tomatoes (Lycopersicon esculentum Mill.) to transplant depth, time of daily irrigation, and polyethylene mulch color. Five-week-old tomato transplants were planted to a depth of either 7.5 or 15.0 cm, drip irrigated every other day for 2.5 h starting at either 7:30 am or 2:30 pm for 80 d following transplanting, and mulched with white-surface (white on black) or black polyethylene. Soil temperatures were recorded daily at 4:00 pm for 21 d from the beginning of fruit set (2 weeks following transplanting) until the tomato canopy shaded the mulch surface. Transplanting tomatoes to a depth of 15.0 cm significantly increased marketable yield in both years and the total yield in 1 year of this study. Mean fruit mass was not influenced by transplant depth, but plant dry mass was significantly increased by deeper transplanting in 1995. Morning irrigation increased the marketable and total yields and mean fruit mass in both years and plant dry mass in 1995. White-surface mulch had a similar effect on yield and fruit mass. Soil temperature was significantly lower at the 15.0-cm depth than at 7.5 cm in both years. Morning irrigation and white-surface polyethylene mulch also significantly reduced soil temperature in both years.
Growth of `Tifway' Bermudagrass Following Application of Nitrogen and Iron with Trinexapac-ethyl
Authors: Johnson B. Jack
Published: February 2019

A field study was conducted to assess the effects of N and Fe with trinexapac-ethyl (TE) on established `Tifway' bermudagrass (Cynodon dactylon × C. transvaalensis) during 2 years at Griffin, Ga. There were no TE × Fe or N treatment interactions when applied in three applications at 4-week intervals each year. Combinations of Fe with TE improved turfgrass quality over TE alone at 1 to 2 weeks after each treatment. The improvement from Fe sources was 17 % higher with Sprint 300 and SoluPlex, 33% higher with Ferromec and LawnPlex, and 67% higher with ferrous sulfate. Vegetative suppression of `Tifway' bermudagrass at 14 weeks after treatment ranged from 46% in 1994 to 28% in 1995 when treated with TE at 0.1 kg·ha-1 in three applications at 4-week intervals. Neither N or Fe influenced vegetative growth when applied with TE. Chemical name used: 4 (cyclopropyl-α-hydroxy-methylene)-3.5-dioxocyclohexanecarboxlic acid ethyl ester (trinexapac-ethyl).
Use of Ethephon as a Controlled Abscission Agent on Paprika Pepper
Authors: Kahn Brian A. , Motes James E. , Maness Niels O.
Published: February 2019

Mechanical harvest of paprika pepper (Capsicum annuum L.) produces a mixture of marketable and unmarketable fruit. Our objective was to increase the percentage of marketable red fruit in a once-over harvest by using ethephon to remove late-developing flower buds, blooms, and green fruit. Three experiments were conducted on field-grown plants in southwestern Oklahoma. We tested ethephon solutions of 0, 1000, 2000, 3000, and 4000 μL·L-1 as a one-time foliar application on various dates in September and October. Total dry mass of harvested fruit decreased linearly as ethephon rate increased in all experiments. Marketable fruit, as a percentage of total harvested fruit mass, increased linearly with ethephon rate in two of three experiments. Ethephon decreased the percent of total harvested fruit mass due to green fruit in all experiments. We recommend a single application of ethephon at about 2000 to 3000 μL·L-1 as a controlled abscission agent to increase the percentage of harvested red fruit in paprika pepper. The precise timing of the application will vary with the situation, but the last 10 days in September seemed an appropriate interval for southwestern Oklahoma. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).
Biological Control of Rose Powdery Mildew with the Antagonist Yeast Tilletiopsis pallescens
Authors: Ng Ken K. , MacDonald Leslie , Punja Zamir K.
Published: February 2019

The efficacy of Tilletiopsis pallescens Gokhale, a naturally occurring ballistosporeforming yeast isolated from mildew-infected leaves, was evaluated as a biological control agent against rose powdery mildew [Sphaerotheca pannosa (Wallr.:Fr.) Lév. var. rosae Woronichin]. Two trials were conducted on potted rose (Rosa sp.) plants (1-year-old cv. Cardinal Pink) under commercial greenhouse-growing conditions during the summer (June to September) when mildew was most severe. Mildew-infected plants were subjected to one of four treatments: a T. pallescens spore suspension applied three times (3–4 d apart), distilled water (applied three times), one application of T. pallescens spore suspension, or one application of culture filtrate without spores. Two weeks after treatment began, mildew development was evaluated by enumerating conidial density on sampled leaflets. Sporulation was significantly reduced (by 97%–98%) on plants treated with three applications of T. pallescens spore suspension, compared to a 47%–57% reduction on plants treated with three applications of distilled water. There was no significant difference in conidial density between plants treated with one application of T. pallescens spore suspension and plants treated with one application of its culture filtrate, with a 78%–94% reduction in conidia, which was significantly higher than for the water treatment. The mode(s) of action of T. pallescens appears to be eradicant and associated with enzymes or metabolites produced in the culture filtrate. The results from this study demonstrate the potential for biological control of rose powdery mildew under commercial growing conditions in British Columbia.
Market Quality of Guavas after Hot-water Quarantine Treatment and Application of Carnauba Wax Coating
Authors: McGuire Raymond G.
Published: February 2019

Immersion of guavas (Psidium guajava L.) for 35 min in water at 46.1 ± 0.2 °C slowed softening, sweetening, and color development of fruit and delayed ripening by 2 days. Heat treatment also increased susceptibility to chilling injury, decay, and weight loss in storage, but overall loss of quality was minimal. Waxing fruit within 90 min of heat treatment exacerbated chilling injury, further delayed ripening with a concomitant increase in the percentage of fruit not ripening, and caused fruit to remain greener. Waxed fruit had a lower acidity and soluble solids concentration and did not appear to ripen normally. Although heating did not appreciably affect the percentage of fruit that failed to ripen, the combination of heating and nearly immediate waxing increased the proportion not ripening to 45%. Heat and wax treatments, alone or in combination, caused CO2 levels to increase significantly before the initiation of ripening, but waxing also reduced the O2 content of fruit at this time. Before ripening, O2 levels were inversely correlated (r ≤ – 0.950) with injury, firmness, date and percentage of fruit ripening, and pH and directly correlated (r ≥ 0.950) with peel color and the concentration of acids and sugars in the pulp. Delaying the waxing of heat-treated guavas or reconditioning them for 24 h at 20 °C before cold storage promoted normal ripening and helped to maintain the quality of heat-treated fruit.
Rooting Stem Cuttings of Atlantic White Cedar Outdoors in Containers
Authors: Hinesley L. Eric , Snelling Layne K.
Published: February 2019

Stem cuttings of Atlantic white cedar [Chamaecyparis thyoides (L.) B.S.P.] were collected in early June 1995, divided into two parts (distal tip and proximal segment), and rooted for 12 weeks in shaded containers outdoors. Total rooting was near 80%. Mist intervals of 8 and 15 min yielded the best rooting percentages and the least dieback and injury. Two rooting media were tested, with similar results. Rooting was slightly higher in Spencer-Lemaire Rootrainers (Hillson size), compared to RoPak Multi-pots (#45). More than 90% of the tips rooted, even without IBA treatment. Auxin improved rooting of stem segments, but the difference between IBA at 1.5 and 3.0 g·L-1 was small. Yield of cuttings suitable for transplanting or potting was 80% for tips, 58% for segments. Dividing stem cuttings into two or more parts allows multiplication of rooted propagules from a collection. Chemical name used: 1H-indole-3-butyric acid (IBA).
Basal Pruning Fraser Fir Christmas Trees
Authors: Hinesley L. Eric , Snelling Layne K.
Published: February 2019

Fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees were basal pruned (branches were removed from the lower 15 to 25 cm of the stem, i.e., handle) at heights ranging from 0.6 to 0.9 m up to 1.5 to 1.8 m tall, and were harvested 2 to 4 years later. Basal pruning reduced cutting time ≈25%, and baling time ≈10%. Commercial height and stem diameter were unaffected, but the average harvest weight of pruned trees 2.1 to 2.4 m tall (2 to 4 years after basal pruning) was reduced ≈1.4 kg.
Internships for Students: A College-wide Program with Active Faculty Involvement
Authors: Ferriss Terry L.
Published: February 2019

The College of Agriculture, Food and Environmental Science at the Univ. of Wisconsin–River Falls was established in 1968 and has evolved into a successful program, placing more than 200 students on internships annually. Much of the program's success has been attributed to the commitment and active involvement of faculty. Each discipline within the College of Agriculture has one or more faculty designated to participate in the program. These faculty are referred to as the Faculty Coordinators. The Faculty Coordinators assist students in identifying work sites, collaborate with the student and employer to develop and approve learning objectives and a special internship project, read and evaluate student's on-going progress reports, make on-site visits with the interns and employers and evaluate the student's overall experience. The program is centrally administered through the Program Director, who reports to the Dean of the College. A Program Assistant provides clerical and office support for the Faculty Coordinators and Director. Six faculty members and the Director serve on the College's Internship Committee, which establishes and reviews the policies and procedures affecting the program. The program provides students with an opportunity to integrate classroom theory with practical experience, explore career opportunities, enhance and develop technical, interpersonal, and communication skills, and develop professional contacts.
Developing a Maturity Index for New Cherry Cultivars Growing in the San Joaquin Valley
Authors: Crisosto Carlos H. , Garner David , Crisosto Gayle M. , Southwick Steve , Ritenour Mark A.
Published: February 2019

During the past 5 years, we have investigated the relationship between cherry skin color stages (light red, 50% bright red, 100% bright, and dark red) measured at harvest and harvest/shipping quality for `Brooks', `Tulare', and `King' cultivars. This relationship was studied with fruit grown in different geographic locations within the San Joaquin Valley (SJV). SSC increased, but titratable acidity levels did not change as cherries matured to the dark skin color. The perception of sweetness, sourness, and cherry flavor by a trained taste panel was related to the different cherry skin color stages. Dark red color developed on cherries picked at earlier color stages after simulated shipment. Pitting and stem browning were the main market life limitations. Pitting, stem browning, and decay were higher on cherries picked at the dark and 100% bright red colors than cherries picked at earlier stages.
Nematicide Trials on Paprika Pepper
Authors: Kahn Brian A. , Damicone John P. , Jackson Kenneth E. , Motes James E. , Payton Mark E.
Published: February 2019

Nematodes (Meloidogyne sp.) are a potential problem when paprika peppers (Capsicum annuum L.) are grown in fields historically planted to peanuts (Arachis hypogaea L.). Nine nematicide treatments were evaluated over 3 years in field experiments on paprika pepper. Materials tested included the chitin nematicide ClandoSan and six chemicals: fosthiazate, carbofuran, aldicarb, oxamyl, fenamiphos, and dichloropropene. Stands at harvest were increased relative to the control by ClandoSan in 2 of 3 years. Other horticultural effects (plant dry mass and fruit yield) were minimal for all nine nematicide treatments. No one nematicide treatment consistently reduced nematode counts at harvest relative to the control. Nematode counts at harvest were greater in plots treated with ClandoSan than in plots treated with any other material in 2 of 3 years. Nematicide treatments were not cost effective under the conditions of these studies.
Long-term Effects of Triazol Growth Regulators on Stem Elongation of Rhododendron and Kalmia
Authors: Gent Martin P.N.
Published: February 2019

The persistence of effects of paclobutrazol or uniconazol on stem elongation was determined for several years after large-leaf Rhododendron and Kalmia latifolia were treated with a single-spray application of these triazol growth-regulator chemicals. Potted plants were treated in the second year from propagation, and transplanted into the field in the following spring. The elongation of stems was measured in the year of application and in the following 2 to 4 years. Treatments with a wide range of doses were applied in 1991, 1992, or 1995. For all except the most-dilute applications, stem elongation was retarded in the year following application. At the highest doses, stem growth was inhibited 2 years following application. The results could be explained by a model of growth regulator action that assumed stem elongation was inversely related to amount of growth regulator applied. The dose response coefficient for paclobutrazol was less than that for uniconazol. The dose that inhibited stem elongation one-half as much as a saturating dose was about 0.5 and 0.05 mg/plant, for paclobutrazol and uniconazol, respectively. The dose response coefficient decreased exponentially with time after application, with an exponential time constant of about 2/year. The model predicted a dose of growth regulator that inhibited 0.9 of stem elongation immediately after application would continue to inhibit 0.5 of stem elongation in the following year.
Effect of Nitrogen, Gibberellic Acid, Triadimefon, and Kinetin on the Seedling Growth of Sapodilla (Achras sapota) and Tamarind (Tamarindus indica)
Authors: Morales-Payan J.P. , Santos B.M.
Published: February 2019

Container experiments were conducted in the Dominican Republic to determine the effects of nitrogen, gibberellic acid, triadimefon, and kinetin on the seedling growth of sapodilla (Achras sapota) and tamarind (Tamarindus indica). Plants were started from seeds on cylindrical plastic containers (20 × 20 cm) filled with an artificial a 1:1 mixture of sand and loamy soil, allowing the growth of only one plant per container. Nitrogen rates (0.5, 0.75, and 1.0 g N per plant, applied as ammonium sulfate) were factorially combined with the rates (0, 25, 50, 75, and 100 ppm each) of the regulators. When the plants had three true leaves, nitrogen was applied to the growing mixture, whereas the growth regulators were applied foliarly. Plants were allowed to grow during 60 days after treatment. There were no nitrogen and regulator interactions. Kinetin treatments did not significantly influence shoot dry weight and height in either species. Both species responded with linearly increased height, internode length, and dry weight to increasing GA3 concentrations. Increasing rates of the growth retardant triadimefon significantly reduced the internode length and total height of sapodilla and tamarind seedlings. These results suggest that gibberellin and triadimefon could be effectively used as a means to stimulate or retard, respectively, the growth of sapodilla and tamarind.
Influence of Folcysteine and Nitrogen on Lettuce (Lactuca sativa) Yield
Authors: Morales-Payan J.P. , Santos B.M.
Published: February 2019

Greenhouse experiments were conducted in the Dominican Republic to determine the effect nitrogen (N) and the biostimulant folcysteine on the yield of `Black Seeded Simpson' lettuce. Plants were individually grown in plastic containers filled with loamy soil and treated with combinations of N and folcysteine. N rates (35, 70, 105, 140, 175, and 210 kg/ha) were applied at planting, while folcysteine (0, 100, 200, 300, and 400 ppm) was applied as a foliar spray when the plants had five true leaves. Plants were harvested 50 days after planting. The results show that there was an interaction of the effects of N and folcysteine on lettuce yield. The highest yields were obtained with combinations of 300–400 ppm of folcysteine and 140–210 kg N.
Evaluation of the Genetic Diversity Castanea pumila var. ozarkensis through Isozyme Analysis and DNA Amplification Fingerprinting
Authors: Dane Fenny , Huang Hongwen
Published: February 2019

The genetic diversity within and between four geographic populations of the Ozark chinkapin was evaluated and partitioned in order to gain an understanding of the overall genetic diversity and structure of this species, which will be instrumental for its preservation and germplasm enhancement. Nuts of chinkapin trees along the natural range of the species in the Sylamore Ranger District of the Ozark National Forest in Arkansas were collected and evaluated with isozyme and RAPD markers scattered across the genome. Allozyme differences were detected among the geographic populations. Allele frequencies will be determined and subjected to genetic diversity statistics. A conservation plan will be recommended.
Influence of Ontological Age on Adventitious Bud and Shoot Formation of Pawpaw [Asimina triloba (L.) Dunal] Nodal Explants
Authors: Finneseth C.L.H. , Layne Desmond R. , Geneve R.L.
Published: February 2019

Clonal propagation of pawpaw is currently limited to budding and grafting. A tissue-culture system to rapidly produce clonal material would be valuable for both production and preservation of germplasm. Forced scion wood, shoots from root cuttings, and seedlings were explant sources for ontologically mature, intermediate, and juvenile ages, respectively. Preliminary data indicated that nodal explants had more rapid adventitious shoot formation than shoot tip explants. Disinfestation protocols were developed for each explant source. Nodal explants were cultured on MS medium supplemented with 10 μM BA and 0.1 μM TDZ. Within 3 weeks, 60% of the seedling explants had expanded axillary buds, while no bud expansion was observed for explants of either the intermediate or mature sources. By 6 weeks, seedling axillary shoots had elongated and were suitable for subculture. By 8 weeks, multiple adventitious buds and shoots had formed on all seedling explants. At this same time, axillary shoots began to elongate on intermediate source explants, but mature source explants appeared to be recalcitrant. Explant exudation caused medium darkening, but, by reducing the transfer interval from 4 to 2 weeks, discoloration was minimized. Mature source explants were maintained in culture and after ≈7 months, axillary bud expansion occurred in a small percentage of these explants.
Factors Influencing Shoot Regeneration and ß-Glucuronidase Expression from `Royal Gala' Apple Internodes
Authors: Liu Qingzhong , Salih Sarbagh , Hammerschlag Freddi
Published: February 2019

Factors influencing regeneration and ß-glucuronidase expression from apple (Malus × domestica Borkh.) stem internodes were studied as part of a program to develop transgenic `Royal Gala' apple with improved disease resistance. The early stages of the transformation process were monitored by counting the number of ß-glucuronidase (GUS) expressing zones immediately after co-cultivation of explants with Agrobacterium tumefaciens supervirulent strain EHA105 (p35SGUS_INT) and by counting the number of GUS-expressing calli developing on explants 2 weeks after co-cultivation. Etiolated shoots were produced from in vitro shoots cultured for 2 weeks in the light followed by 2 weeks in the dark and were compared with shoots cultured for 4 weeks in the light (green shoots). First internodes from etiolated shoots produced three, 10 and 100 times the number of shoots regenerated from second, third, and fourth internodal explants, respectively, and produced seven times the number of shoots compared with similar explants from green shoots. 100% of first internodes from etiolated shoots exhibited GUS-expressing zones and yielded twice as many GUS-expressing zones when compared with leaf explants from green shoots, which exhibited GUS-expressing zones in only 60% of the explants. An average of nine GUS-expressing calli per explant were produced on first internodes from etiolated shoots 2 weeks after co-cultivation.
Callogenesis and Organogenesis as Affected by NAA and Picloram Concentrations under an Aluminum Medium in Malus prunifolia
Authors: de L. Fortes Gerson R. , de F. Oliveira Marisa , Muller Nilvane T. G. , Faria Janine T.C. , Andrade Luciana B.
Published: February 2019

The apple crop in Brazil is established in acid soils with low pH. This condition leads to high aluminum levels in the soil. The aim of this work was to evaluate the callogenesis and organogenesis of apple rootstock somatic material under aluminum and different auxins concentrations. Internodes of apple rootstock cv. Marubakaido were inoculated in a MS medium containing aluminum (10 mg·L–1), BAP (5.0 mg·L–1), MS vitamins, myo-inositol (100 mg·L–1), sucrose (30 g·L–1), and agar (6.0 g·L–1). Picloram and NAA were tested at (0, 0.5, 1.0, 1.5, and 2.0 μM. Internodes were inoculated in test tubes and the whole material remained in dark for 3 weeks and then to 16-h photoperiod, 25 ± 2°C and 2000 lux. NAA-treated explants performed better than picloram ones. Callus intensity was maximized at 0.5 μM NAA. Although the higher percentage of callus formed (91%) occurred for NAA at 1.0 μM and 82% for picloram at the same concentration. NAA-treated explants responded for 62% of regenerated callus, while picloram presented only 6%. NAA also increased the mean number of shoots (3.54) and buds (11.52) as compared to picloram, which presented 1.40 and 2.78, respectively.
Screening of Mycorrhizal Arbuscular Fungi for Nursery Production of Banana Vitroplants
Authors: Michel-Rosales A. , Farias J. , Guzman S. , Lopez G. , Valdovinos G.
Published: February 2019

In western Mexico, banana is traditionally multiplied by vegetative reproduction in the orchard; recently, micropropagation of this species has increased considerably. Banana has been shown to give a positive response to AM fungal inoculation. However, the selection of efficient AM fungi species, currently propagated in vitro, has not been documented. The selection of the most-effective arbuscular mycorrhizal (AM) fungi for growth enhancement of banana vitroplants is the first step toward development of an AM inoculation system. This work reports the effect of nursery inoculation of Glomus aggregatum, G. clarum, G. etunicatum, G. intraradices, G. monosporum, G. mosseae, and Gigaspora margarita on the banana vitroplants growth. Pots (4 kg) containing a mixture of soil and coconut fiber (1:1) sterilized with methyl bromide were used. Treatments were arranged under a fully randomized experimental design with eight replications. The plants were harvested 120 days after inoculation and plant height, number of leaves, leaf area, fresh weight of roots, mycorrhizal colonization, and intensity of infection were measured. Glomus etunicatum, G. monosporum, G. mosseae, and G. aggregatum were shown to be the most-effective endophytes. Plant height was increased, as well as the production of banana roots in response to mycorrhizal inoculation with these fungi. On the other hand, G. intraradices and G. clarum showed low levels of colonization. The data clearly show the most efficient AM fungi for future inoculation studies in nursery banana production.
Arbuscular Mycorrhizal (AM) Fungal Isolates Differentially Altered Morphology of Young `Volkamer' Lemon Plants under Well-watered Conditions
Authors: Fidelibus Matthew W. , Martin Chris A. , Stutz Jean C.
Published: February 2019

Four AM fungal isolates (Glomus sp.) were screened for effects on growth of `Volkamer' lemon (Citrus volkameriana Ten. and Pasq.) under well-watered conditions. Plants were inoculated with an isolate of AM fungi, or non-inoculated. Non-mycorrhizal plants received more phosphorus (P) fertilizer than mycorrhizal plants because mycorrhizae enhance P uptake. Mycorrhizal and non-mycorrhizal plants were grown in 8-liter containers for 3 months in a glasshouse. Plants were then harvested, and root length colonized by mycorrhizal fungi, leaf P concentration, and plant growth were determined. Root length colonized by AM fungi differed among isolates; control plants were non-mycorrhizal. Leaf P concentration was in the optimal range for all plants; however, plants colonized by Glomus mosseae Isolate 51C had higher leaf P concentration than non-mycorrhizal plants. Plants colonized by Glomus AZ112 had higher leaf P concentration than all other plants. All plants had similar canopy leaf area, shoot length, and shoot dry mass. Plants colonized with AM fungi, except Glomus mosseae Isolate 51C, had longer root length and greater root dry mass than non-mycorrhizal plants. All mycorrhizal plants had lower shoot:root dry mass and leaf area:root length ratios than non-mycorrhizal plants. Our results showed that under optimal P nutrition and well-watered conditions, AM fungal isolates differentially altered the morphology of citrus plants by stimulating root growth.
Controlling Root and Weed Growth in a Nursery Crop Sandbed Subirrigation System
Authors: Svenson Sven E. , Adams Dave , Ticknor R.L.
Published: February 2019

Roots growing out of container drainholes, and weeds growing on the sandbed surface, are the two major problems associated with the use of sandbed subirrigation systems for nursery crop production. Adjusting the water level within the sandbed, application of herbicides to the sandbed surface, placing weed barriers on the sandbed surface, and placing copper hydroxide-treated weed barriers on the sandbed surface were tested to control rooting-out and weed growth. Coppertreated barriers provided the best control of rooting-out and weed growth without reducing the shoot growth of heather, forsythia, or weigela. Several herbicides provided good control of rooting-out and weed growth without reducing the shoot growth of daphne.
Effects of Flood Irrigation Frequencies on Yield and Quality of `Lisbon' Lemons in Southwestern Arizona
Authors: Wilcox Mark
Published: February 2019

A 3-year study (1993–96) was recently completed evaluating the response of `Lisbon' lemons to various flood irrigation intervals. The irrigation intervals were based on soil moisture depletion (SMD), as calculated from frequent neutron probe soil moisture measurements at various depths. Individual treatments were irrigated when total SMD was 25%, 40%, 55%, and 70% respectively. Results obtained indicate that fruit growth was significantly reduced at the 70% SMD regime. In the first (ring) picks the most frequent (25% SMD) and the frequent (75% SMD) had reduced yields. Combined data from the three years indicated that early yields were maximized at the 40% SMD regime. Differences in fruit quality (peel thickness, percentage juice, solid/acid ratio, etc.) were not generally statistically significant at the 0.05 probability level.
Hardiness and Ornamental Characteristics of Lacebark Elm Selections
Authors: Pair John C. , Rajashekar Channa , Shelton Michael
Published: February 2019

Numerous cultivars of lacebark elm (Ulmus parvifolia) have been introduced recently without adequate testing of their hardiness. A block of commercial cultivars plus numerous experimental numbers were established to observe differences in growth form, ornamental characteristics, and cold hardiness. Laboratory freezing tests were conducted from November to March over a 3-year period to determine acclimation and deacclimation to low temperatures. Stem sections approximately 5 cm long were sealed in test tubes and placed in a low-temperature programmable freezer maintained at 0°C. Samples were cooled by approximately 6°C per hour from 0 to –48°C and held for 1 h at each temperature. Samples were then removed, allowed to thaw at room temperature, and held for 7 to 10 days. Stem samples were sectioned longitudinally to observe browning in xylem and bark tissues. During the winter of 1995–96, no visible injury could be noted on trees in the field in spite of very dry, desiccating weather with temperatures reaching –23°C. Laboratory freezing tests indicated acclimation to –30°C by 18 Dec. 1995 on several cultivars. During warm periods in February, deacclimation occurred on many selections to –18°C, whereas others maintained a killing point of –30°C. Growth form, bark exfoliation, and fall color varied among cultivars.
RAPD Markers Linked to Major Genes for Common Bacterial Blight and Purple Flower Color in a Tepary Bean Cross
Authors: Park S.O. , Dursun A. , Coyne D.P.
Published: February 2019

Common bacterial blight (CBB), incited by Xanthomonas campestris pv. phaseoli (Xcp), is an important disease of common bean (Phaseolus vulgaris L.). Tepary bean (P. acutifolius A. Gray) is of interest to bean breeders because of resistance to CBB. The objective was to identify RAPD markers linked to major dominant genes for CBB resistance and purple flower color using bulked segregant analysis in an F2 population from a tepary bean cross Nebr#19 [resistant (R) to CBB and white flower color] × Nebr#4B [susceptible (S) to CBB and purple flower color]. Ten RAPD primers (600 RAPD primers screened) showed polymorphisms between bulked DNA derived from R and S plants. All markers showed coupling linkage with CBB resistance. The RAPD marker of G-14 primer was 5.2 cM distant from the gene for resistance to Xcp strain LB-2. The RAPD marker of L-18 primer was 6.8 cM distant from the gene for resistance to Xcp strain SC-4A. The RAPD marker of G-14 primer was 26.2 cM distant from the gene for resistance to Xcp strain EK-11. Seven RAPD primers showed polymorphisms between bulked DNA derived from purple and white flower plants. All markers showed coupling linkage with the gene for purple flower color. The RAPD marker of Y-6 primer was 3.6 cM distant from the gene for purple flower color.