bluuebunny/crossref_metadata_2025 huggingface dataset:
Ornamental Grasses, Are They Acceptable Alternatives for Low-maintenance Landscapes?
Authors: Armstrong Traci , Wolfe J.E. , Bradley J.C. , Zajicek J.M.
Published: February 2019

Ornamental grasses are currently growing in popularity and are being used in parks, public plantings, and commercial landscapes. This study was developed to determine the esthetic appeal of 12 ornamental grasses and evaluate public attitude toward the use of these grasses in low-maintenance landscapes. Grasses were selected for this evaluation using the following criteria: recommendations of experts in the ornamental grass field; material used in the nursery trade; and recommendations in popular literature. Two field sites were prepared and planted in the Spring 1991 and 1992. Both sites were maintained and irrigated to enhance the survivability of the grasses. The survey was conducted on several dates in the Fall 1992. Participants responded to questions regarding ornamental grass use, and the need for research on water conservation in landscapes. In addition, participants were asked to rank the individual grass species as to their accept-ability for landscape use. The results of the survey indicate that visual aesthetics are a major factor in public acceptance of landscape materials. In addition, the majority of ornamental grasses tested in this study were acceptable alternatives for low-maintenance landscapes with native and introduced species equal in performance.
Effects of Different Durations and Timing of Far-red-deficient Environments on Chrysanthemum Growth
Authors: Carey Glenn , Bachman Gary , McMahon Margaret
Published: February 2019

The effect on plant height and internode length of `Iridon' chrysanthemum by far-red-deficient environments for two different durations was evaluated. Far-red deficiency was achieved by placing plants under double-walled polycarbonate panels filled with 6% (w/v) copper sulfate (CuSO4) solution. Controls were polycarbonate panels without CuSO4 solution. The plants were divided at random into four groups. One group was exposed all day to the CuSO4-filtered (ADCu) environment and another to all-day clear (ADCl) environment. Another set of plants were grown under CuSO4 filters and moved under clear filters 1 h before sunset each day (EODCl), while the last set of plants were grown under clear panels and moved under CuSO4 panels 1 h before sunset each day (EODCu). Plants moved at the end of the day were moved back to their original chambers after dark each night. The experiment was replicated. Overall change in plant height and average internode lengths were measured. The results were compared to ADCl (control). A 31% reduction in plant height was observed for EODCl, 42% reduction for ADCu, and 25% reduction for EODCu. Average internode length was reduced 11% for EODCl, 14% for EODCu, and 33% for ADCu.
Effects of Chilling, Ethanol, and Heat Shock on Enzyme Expression in Cucumber Seedling Roots
Authors: Boyd Windy A. , Jennings Paul H.
Published: February 2019

Chilling-sensitive cucumber seedlings that are treated with ethanol or heat-shocked have shown an increase in chilling tolerance. The mechanisms that regulate this response have not been identified. Cucumber seeds were germinated for 24 h and then treated with 500 mM ethanol for 2 h or heat-shocked at 40C for 3 h. Immediately after treatment, roots were excised and catalase activity was assayed. Another set of control and treated seeds were chilled for 72 h and catalase was assayed at the end of the chilling period. Comparisons will be presented between catalase activity levels before and after chilling, as well as between the control and treated groups. Treatments of ethanol and heat shock resulted in an increase in catalase activity when compared to controls.
Cu(OH)2 Affects the Growth and Root Structure of Two Woody Ornamental Species
Authors: Buechel Tom J. , Hasselkus Edward R. , McCown Brent H.
Published: February 2019

Root girdling and deformation are problems that occur in containerized woody ornamentals. Two small trees, the coarse-rooted Magnolia × loebneri `Leonard Messel' (grown in 5-gal containers), and the fine-rooted Crataegus × viridis `Winterking' (6' bare root), were transplanted into 10-gal containers, some of which were treated with “SpinOut” [a latex paint containing 100 g Cu(OH)2/liter]. The plants were grown in a pot-in-pot system for 3 months, after which new roots were analyzed for mat formation and branching pattern. No significant differences in shoot growth that could be attributed to the Cu(OH)2 treatment were observed. The treated containers prevented both root encirclement and reformation of matted roots, and resulted in a more-dense and fibrous root system than that observed in untreated containers. The differences were greatest with the coarse-rooted magnolia. The use of containers treated with copper compounds may be an effective means to reduce root problems commonly observed in modern containerized ornamental production.
Physiological and Biochemical Changes on the Roots of Aeroponically Grown, Phosphate-starved Tomatoes
Authors: Biddinger Eric J. , Liu Chunming , Raghothama K.G.
Published: February 2019

Phosphate starvation in plants results in altered biochemical and physiological responses. We are interested in understanding the changes that occur in response to phosphate starvation in the roots of tomato plants. Plants were grown in an aeroponic system developed by L.A. Peterson at the Univ. of Wisconsin. Aeroponically grown tomato plants were treated with various concentrations of phosphate, ranging from to 250 mM. Phosphate-starved plants exhibited significantly higher root to shoot ratios and a 40% decrease in the chlorophyll content of the leaves. Several changes in essential nutrient content were also observed. The phosphate concentration of both root and shoot tissues decreased as the Pi content of the nutrient solution decreased. Whereas the ratio of phosphate content in roots compared to the shoots did not change significantly in response to Pi starvation. Phosphate-starved plants accumulated significantly higher amount of magnesium in stem tissues. Furthermore, it also resulted in an increased accumulation of potassium in roots. Interestingly, the total extractable RNA from phosphate-starved roots was 1/5th of that of control roots. There was also a noticeable decrease (50%) in the total extractable RNA content of leaves from phosphate-starved plants.
Evaluation of Temperature and Moisture Content during Storage on the Germination of Flowering Annual Seed
Authors: Carpenter William J. , Ostmark Eric R. , Cornell John A.
Published: February 2019

Various combinations of temperature and moisture contents were used in evaluating the seed storage of nine genera of annual flowers. Relative humidity (RH) levels of 11%, 32%, 52%, and 75% provided wide ranges in seed moisture during storage at 5, 15, and 25C. At each temperature, total germination percentages (G) generally declined as seed moisture content increased during storage. The seed moisture range giving the highest G after 12 months of storage was determined for each temperature and plant genus. For all genera, seed moisture contents during storage increased as storage temperatures increased at constant RH levels. Moisture contents at 25C storage were 37%, 34%, 29%, and 20% higher than at 5C when RH levels were at 11%, 32%, 52%, and 75%, respectively.
Fertilization Rate Affects Production and Postharvest Quality of Tapeinochilus ananassae Flowers
Authors: Broschat Timothy K.
Published: February 2019

Greenhouse-grown Tapeinochilus ananassae Hassk. were fertilized with 1110, 2220, or 4440 g of Osmocote 17N–3P–10K/m2 per year for 4 years. Plants receiving the medium rate of fertilizer produced the most flowers, while the highest fertilization rate resulted in the fewest. Flower stalk length decreased each year after planting, but cutting back the vegetative shoots to the ground resulted in increased flower stalk length the following year. Fertilization with the highest rate resulted in reduced flower postharvest life, but floral preservatives and ethylene inhibitors had no effect on postharvest life.
Substrate Temperatures Influence Root and Shoot Growth of Southern Highbush and Rabbiteye Blueberries
Authors: Spiers James M.
Published: February 2019

A greenhouse study was conducted to evaluate the influence of substrate temperatures (16, 27, and 38C) on root and shoot growth of six blueberry (Vaccinium spp.) clones (three clones each of two types). Between types, southern highbush (primarily V. corymbosum L.) produced more roots and total growth than rabbiteye (V. ashei Reade). Comparing clones, `Gulfcoast' (southern highbush) was the most vigorous and `Tifblue' (rabbiteye) the least vigorous. Each clone had a negative linear response to substrate temperatures in all growth characteristics. Root and shoot growth was best at 16C. This study indicates that both rabbiteye and southern highbush blueberries would respond favorably to cultural practices that lower soil temperatures during the summer growing season.
Planting Depth Affects Survival, Root Growth, and Nutrient Content of Transplanted Pygmy Date Palms
Authors: Broschat Timothy K.
Published: February 2019

Mature pygmy date palms (Phoenix roebelenii O'Brien) having a minimum of 90 cm of clear trunk were transplanted into a field nursery at their original depth or with 15, 30, 60, or 90 cm of soil above the original rootball. Palms planted at the original level or with the visible portion of the root initiation zone buried had the largest canopies, highest survival rates, and lowest incidence of Mn deficiency 15 months after transplanting. Palms planted 90 cm deep had only a 40% survival rate, with small, Mn-deficient canopies on surviving palms. Palms whose original rootballs were planted 90 cm deep had very poor or no root growth at any level, but had elevated Fe levels in the foliage. None of the deeply planted palms produced any new adventitious roots higher than 15 cm above the visible portion of the root initiation zone.
Pre-sidedress Soil Nitrate Test for Sweet Corn
Authors: Heckman J.R. , Hlubik W.T. , Prostak D.J. , Paterson J.W.
Published: February 2019

Research was conducted with sweet corn (Zea mays L.) to evaluate the presidedress soil NO3 test (PSNT) originally developed for use on field corn on a wide range of New Jersey soils. Soil NO3-N concentrations reflected differences in N availability due to manure or preplant N application. The relationship between soil NO3-N concentration and relative yield of marketable ears was examined using Cate–Nelson analysis to define the PSNT critical level. Soil NO3-N concentrations >25 mg·kg–1 were associated with relative yields at ≥92%. The success rate for the PSNT critical level was 85% for predicting whether sidedress N was needed. Including NH4-N in the soil analysis did not improve the accuracy of the soil test for predicting whether sidedress N was needed. Although the PSNT is quite accurate in identifying N-sufficient sites, it appears to offer only limited guidance in making N-fertilizer rate predictions. The PSNT is most useful on manured soils, which frequently have sufficient N. The test likely will help decrease the practice of applying “insurance” fertilizer N and the ensuing potential for NO3 pollution of the environment.
Reduced Heat Shock Period of `Sharwil' Avocado for Cold Tolerance in Quarantine Cold Treatment
Authors: Nishijima Kate A. , Chan Harvey T. , Sanxter Suzanne S. , Linse Edward S.
Published: February 2019

A reduced heat shock period for `Sharwil' avocado (Persea americana Mill.) before quarantine cold treatment is described. The shortened heat pretreatment period of 8 to 12 hours, rather than the originally recommended 18 hours at 38C, is effective in reducing chilling injury symptoms when the pulp is at ≤2.2C during 16 days of storage. The reduced durations and the range of pretreatment hours affords packinghouses greater efficiency and more flexibility and will reduce handling costs relative to the longer exposure.
Sucrose Improves the Postharvest Life of Cut Flowers of a Hybrid Limonium
Authors: Doi Motoaki , Reid Michael S.
Published: February 2019

Regardless of their maturity at harvest, the vase life of cut inflorescences of the hybrid Limonium `Fantasia' placed in deionized water was 4 to 5 days. A vase solution containing Physan (a quaternary ammonium disinfectant solution) at 200 μl·liter–1 and 20 g sucrose/liter not only prolonged the longevity of individual florets but also promoted bud opening so that the vase life of cut inflorescences extended to 17 days. Pulse treatment with 100 g sucrose/liter in combination with Physan at 200 μl·liter–1 for 12 hours partially substituted for a continuous supply of sucrose. Including 30 mg gibberellic acid/liter in the vase solution was without benefit.
DNA Amplified Fingerprinting, A Useful Tool for Determination of Genetic Origin and Diversity Analysis in Citrus
Authors: Luro François , Laigret Frédéric , Bové Joseph-Marie , Ollitrault Patrick
Published: February 2019

We used three short repetitive nucleotide sequences [(GTG)5, (TCC)5, and (GACA)4] either as radiolabeled probes for hybridization with restricted citrus DNA or as single primers in polymerase chain reaction amplification experiments with total genomic DNA. We tested the ability of the sequences to discriminate between seedlings of zygotic or nucellar origin in the progeny of a Volkamer lemon (Citrus volkameriana Ten. & Pasq.) tree. The genetic variability within two species [Citrus sinensis (L.) Osbeck (sweet oranges) and Citrus reticulata Blanco and relatives (mandarins)] also was evaluated. DNA amplified fingerprinting with single primers was the more successful technique for discriminating between nucellar and zygotic seedlings. Although we were not able to distinguish among 10 cultivars of C. sinensis, all 10 C. reticulata cultivars tested were distinguishable. However, it still is difficult to identify the putative parents of a hybrid plant when the two parental genomes are closely related.
Callus and Somatic Embryogenesis from Cultured Anthers of Service Tree (Sorbus domestica L.)
Authors: Arrillaga Isabel , Lerma Victoria , Pérez-Bermúdez Pedro , Segura Juan
Published: February 2019

The effects of stage of microspore development, cold pretreatment, and growth regulators on the embryogenic response of anthers from service tree (Sorbus domestica L.) are reported. Callus proliferation required the presence of growth regulators in the culture medium, best results being obtained with combinations of auxins and BA. Microspore embryogenesis was only induced when anthers containing tetrads or uninucleate pollen were cultured on BA-supplemented media containing IBA or IAA. A cold pretreatment before anther culture elicited a significant decrease in callus formation and inhibited embryogenesis. Chemical names used: benzyladenine (BA), indole-3-butyric acid (IBA), indole-3-acetic acid (IAA).
Characteristics of Hardwood Cuttings Influence Rooting of Actinidia arguta (Siebold & Zucc.) Planch.
Authors: Beyl Caula A. , Ghale Gokul , Zhang Lianjun
Published: February 2019

Root development of hardwood cuttings of Actinidia arguta was investigated in relation to the size of cuttings and the number of buds. Dormant shoots of 13 Actinidia arguta cultivars and lines were cut into lengths varying from 3.5 to 18 cm and containing one to nine buds. After being treated with 0.3% indolebutyric acid in talc, cuttings were stuck into oasis foam cubes and placed under intermittent mist. Actinidia arguta lines and cultivars included 74-46, 74-55, 124-40, 125-40, 127-40, 119-40-B, `Meader Male', `Meader Female #1', `Geneva #1', `Ananasnaja', `Michigan State', A. arguta cordifolia (Miq.) Bean 1563-51, and a New Zealand A. arguta cordifolia selection. Cultivar significantly affected number of roots, root grade, and length of longest root. In general, cultivars with the highest rooting percentages also had the most and longest roots and the highest root grades. The best cuttings for root formation had eight to nine buds (with three to four in active growth), diameters <2 mm, and lengths >10 cm. Cuttings with five to seven buds (with one to three in active growth), diameters between 2 to 8 mm, and lengths >8 cm exhibited the best root development in terms of number of roots formed, root length, and root grade.
Root Pruning and Trunk Scoring Have Limited Effect on Young Bearing Apple Trees
Authors: Miller Stephen S.
Published: February 2019

To control excessive growth, vigorous `Smoothee Golden Delicious', `Jonagold', `Empire', and `Gala' apple (Malus domestica Borkh.) cultivars on Malling 7A (M.7A) rootstock planted at close in-row spacing (2.5 or 1.8 m) were mechanically root-pruned (RP), trunk-scored (TS; ringing), or both, annually for 3 to 5 years beginning in the fourth leaf. Trees were grown in a deep, well-drained, fertile soil and supplied with trickle irrigation. RP reduced terminal shoot length in 2 of 5 years on `Smoothee Golden Delicious'; trunk cross-sectional area (TCSA) was not affected by RP. TS reduced terminal length in 3 years and TCSA in each of 5 years of treatment on `Smoothee Golden Delicious'. Bloom density was not affected by RP on `Smoothee Golden Delicious' but was increased by TS in two of the three years measured. RP reduced terminal shoot length in `Gala', `Empire', and `Jonagold' in most years and TCSA in 1993 for all cultivars. TS had no effect on shoot length or TCSA in these three cultivars. Effects of RP and TS on yield and fruit size varied with year and cultivar. In general, the effects of RP and TS were inconsistent and often failed to reduce shoot growth or canopy spread. No practical advantage was recognized from these techniques for young apple trees growing on a fertile site with trickle irrigation.
Productivity and Profitability of Some Field-grown Specialty Cut Flowers
Authors: Starman Terri Woods , Cerny Teresa A. , MacKenzie Amy J.
Published: February 2019

The productivity and profitability of annual and perennial field-grown specialty cut-flower species were evaluated for the southeastern United States. Data were collected on 20 annuals and 20 perennials in 1992 and on 19 annuals and 19 perennials (10 in their second year of production) in 1993. Productivity and profitability were based on yield and stem length measurements. Yield was expressed as total number of stems harvested. Income per 30-cm center was predicted from the number of stems ≥41 cm long that were harvested. Some species had high yields but stem lengths were too short for most market outlets. Among those species that combined high yield with long stems and resulted in high profitability without major pest or postharvest problems were the perennials Achillea filipendulina Lam., Echinacea purpurea (L.) Moench, Liatris spicata (L.) Willd., and Platycodon grandiflorus Jacq. A. DC. and the annuals Antirrhinum majus L., Cosmos bipinnatus Cav., Scabiosa atropurpurea L., and Zinnia elegans Jacq. Low overhead of field production coupled with productive species could prove to be profitable.
Seasonal Cold-acclimation Patterns of Sedum spectabile × telephium L. `Autumn Joy' and Sedum spectabile Boreau. `Brilliant'
Authors: Iles Jeffery K. , Agnew Nancy H.
Published: February 2019

Electrolyte leakage and regrowth were measured from September through January to determine cold hardiness of Sedum spectabile × telephium L. `Autumn Joy' and Sedum spectabile Boreau. `Brilliant' plants grown outdoors in central Iowa. Crowns were subjected to 0, –3, –6, –9, –12, –15, –18, –21, –24, or –27C. Regrowth tests were performed on whole crowns and electrolyte leakage was determined on excised tuberous root and crown tissue. Both cultivars were killed at –3C in September, but they acclimated gradually through January. Maximum hardiness was achieved in January, with killing temperatures of –27C for `Autumn Joy' and –21C for `Brilliant'. Regrowth quality ratings were significantly correlated with crown and tuberous root electrolyte leakage measurements, although the relationship was stronger for `Autumn Joy'.
Greenhouse Screening of Corn Gluten Meal as a Natural Control Product for Broadleaf and Grass Weeds
Authors: Bingaman Barbara R. , Christians Nick E.
Published: February 2019

Corn (Zea mays L.) gluten meal (CGM) was evaluated under greenhouse conditions for efficacy on 22 selected monocotyledonous and dicotyledonous weed species. Corn gluten meal was applied at 0, 324, 649, and 973 g·m–2 and as a soil-surface preemergence (PRE) and preplant-incorporated (PPI) weed control product. CGM reduced plant survival, shoot length, and root development of all tested species. Black nightshade (Solanum nigrum L.), common lambsquarters (Chenopodium album L.), creeping bentgrass (Agrostis palustris Huds.), curly dock (Rumex crispus L.), purslane (Portulaca oleracea L.), and redroot pigweed (Amaranthus retroflexus L.) were the most susceptible species. Plant survival and root development for these species were reduced by ≥75%, and shoot length was decreased by >50% when treated PRE and PPI with 324 g CGM/m2. Catchweed bedstraw (Galium aparine L.), dandelion (Taraxacum officinale Weber), giant foxtail (Setaria faberi Herrm.), and smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl] exhibited survival and shoot length reductions >50% and an 80% reduction in root development when treated with PPI CGM at 324 g·m–2. Barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and velvetleaf (Abutilon theophrasti Medic.) were the least susceptible species showing survival reductions ≤31% when treated with 324 g CGM/m2.
Fumigation of Fruit with Acetic Acid to Prevent Postharvest Decay
Authors: Sholberg P.L. , Gaunce A.P.
Published: February 2019

Acetic acid (AA) as a vapor at low concentrations was effective in preventing fruit decay by postharvest fungi. Fumigation with 2.7 or 5.4 mg AA/liter in air at 2 and 20C reduced germination of Botrytis cinerea Pers. and Penicillium expansum Link conidia to zero after they had been dried on 0.5-cm square pieces of dialysis tubing. Decay of `Golden Delicious', `Red Delicious', and `Spartan' apples (Malus domestica Borkh.) inoculated with 20 μl drops of conidia of B. cinerea (1.0 × 105 conidia/ml) or P. expansum (1.0 × 106 conidia/ml) was prevented by fumigating with 2.0 and 2.7 mg AA/liter, respectively. Tomatoes (Lycopersicon esculentum Mill.), grapes (Vitis vinifera L.), and kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et R. Ferguson var. deliciosa] inoculated with B. cinerea or navel oranges (Citrus sinensis L.) inoculated with P. italicum Wehmer did not decay when fumigated with 2.0 mg AA/liter at 5C. AA fumigation at low temperatures (1 and 5C) with 2.0 or 4.0 mg AA/liter prevented decay of `Spartan' and `Red Delicious' apples and `Anjou' pears (Pyrus communis L.) inoculated with B. cinerea and P. expansum, respectively. `Spartan' apples immersed in a suspension of P. expansum conidia (1.4 × 105 conidia/ml) and fumigated with 2.7 mg AA/liter at 5C had an average of 0.7 lesions per fruit compared to 6.1 for nontreated fruit. Increasing the relative humidity from 17% to 98% increased the effectiveness of AA fumigation at 5 and 20C. At the concentrations used in our trials, AA had no apparent phytotoxic effects on the fruit. The potential for commercial fumigation with AA to control postharvest decay of fruit and vegetables appears promising.
Differential Thermal Analysis of St. Augustinegrass
Authors: Philley H.W. , Watson C.E. , Krans J.V. , Goatley J.M. , Matta F.B.
Published: February 2019

The objective of this study was to relate the lethal freezing temperatures of St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] genotypes, as measured by differential thermal analysis (DTA), to winter survival observed in the field. DTA-predicted lethal temperatures of 14 St. Augustinegrass genotypes ranged from –7.7 to –4.7C. Regression of field winter survival vs. DTA-predicted lethal temperatures resulted in an r2 = 0.57 for one field trial that evaluated cultivars with a relatively narrow range of expected freezing tolerance. In a second study evaluating cultivars with a greater range of freezing tolerance, r2 was 0.92 when winter survival was regressed on DTA-predicted lethal temperatures. DTA was successful in measuring freezing avoidance of St. Augustinegrass cultivars.
Root-zone Medium Influences Growth of Poinsettias Treated with Paclobutrazol-impregnated Spikes and Drenches
Authors: Newman Steven E. , Tant Jeffrey S.
Published: February 2019

An experiment was conducted to determine the influence of eight commercial root-zone media (four peat based and four pine bark based) on the effects of paclobutrazol applied to Euphorbia pulcherrima Willd. `Eckespoint Celebrate 2' as an impregnated spike or a drench. Paclobutrazol treatments had the least influence on stem elongation of poinsettias grown in the peat-based medium containing Bacctite, a compressed peat product designed to increase aeration and cation exchange capacity, or composted pine bark ground to a particle size that could pass through an opening 1 cm or smaller. Spikes were more effective at reducing shoot elongation than drenches. Spike treatments also resulted in lower bract dry-matter accumulation than drenches. Paclobutrazol applied as a spike to poinsettias at pinch could combine pinching and chemical growth regulator application into one simultaneous operation. Chemical name used: (±)-(R*,R*)-beta-[(4-chlorophenyl)methyl]-alpha-(1, 1,-dimethyl)-1H-1,2,4,-triazole-1-ethanol (paclobutrazol).
Household Detergent on Tomato: Phytotoxicity and Toxicity to Silverleaf Whitefly
Authors: Vavrina C.S. , Stansly P.A. , Liu T.X.
Published: February 2019

Household detergents were evaluated in field studies on fresh-market tomato (Lycopersicon esculentum Mill.) for insecticidal and phytotoxic effects. Laboratory bioassays were used to examine the toxicity of a household liquid dish detergent on small nymphs of silverleaf whitefly, Bemisia argentifolii Bellows and Perring. The detergents tested proved to be more toxic to whitefly nymphs than the commercial insecticidal soap. Detergent treatments were applied to tomato with a commercial high pressure hydraulic sprayer at 0%, 1%, 2%, 4%, and 8% (by volume) initially and at 0%, 0.25%, 0.5%, 1.0%, and 2.0% (by volume) in subsequent tests. As detergent rate, frequency of application, or both increased, plant dry weight accumulation and fruit yield decreased. Applying detergent also increased time to fruit maturity. A once-a-week application of 0.25% to 0.5% detergent initially applied 2 weeks after transplanting alleviated phytotoxicity and yield reduction problems.
Vegetation-free Area Influences Growth and Establishment of Rabbiteye Blueberry
Authors: NeSmith D. Scott , Krewer Gerard
Published: February 2019

`Tifblue' and `Brightwell' rabbiteye blueberries (Vaccinium ashei Reade) were planted in 1992 in a tall fescue (Festuca arundinacea Schreb.) sod. Vegetation-free areas of various sizes were maintained around plants to determine the area's influence on establishment and growth of young plants. Vegetation-free circles 0 (control), 0.6, 0.9, and 1.5 m in diameter were maintained from 1992 to 1994 by a combination of commercially recommended herbicides and hand-weeding. The treatments resulted in vegetation-free areas of 0, 0.3, 0.6, and 1.8 m2. Fall growth index values (derived from canopy height and width measurements) increased with size of vegetation-free area in each of the three years. The response was positive linear and negative quadratic, with little difference between the 0.6- and 1.8-m2 vegetation-free areas. Average shoot length in Fall 1992 showed a response similar to that of the growth index; total shoot count per plant was not affected by the treatments. Percent fruit set was not influenced by treatments; however, the number of flower buds per plant in Spring 1994 was correlated positively with size of vegetation-free area. The cultivars responded similarly. Thus, vegetation control seems to be important in establishing young rabbiteye blueberry plants, with the optimum vegetation-free area between 0.6 and 1.8 m2 during the first 2 to 3 years after planting.
Cellulose-based Coatings as Carriers for Candida guillermondii and Debaryomyces sp. in Reducing Decay of Oranges
Authors: Potjewijd R. , Nisperos M.O. , Burns J.K. , Parish M. , Baldwin E.A.
Published: February 2019

Varying the cellulose component of coating formulations affected the survival of two yeast biocontrol agents, Candida guillermondii (Castelani) Langeron and Guerra strain US7 and Debaryomyces sp. strain 230, when these yeasts were incorporated into the coating. Using methylcellulose as the main film-former gave the most recovery of the yeasts after an incubation period for both strains. Significant control of decay on naturally infected `Pineapple' and `Valencia' oranges [Citrus sinensis (L.) Osb.] was demonstrated for US7 in a methylcellulose-based coating for the first 2 to 4 weeks of storage at 16C and 90% relative humidity. During this time, US7 in methylcellulose formulations was similar in decay control to a commercial shellac coating with imazalil at 2000 mg·liter–1. A US7 concentration of at least 105 colony-forming units/cm was maintained on the coated fruit surface of `Valencia' oranges for 3 weeks of storage. Suppression of decay by US7 was improved by the addition of glucose and calcium chloride to the coating formulation. Although nearly equal in concentration recovered, Debaryomyces strain 230 was not as effective as US7 in disease suppression of `Pineapple' oranges. The addition of US7 to Nature Seal, a coating material made with methylcellulose, had neither a quantitative nor a qualitative effect on the pathogen population compared to the same formulation without the antagonist. Chemical name used: 1-[2-(2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl]-1H-imidazole (imazalil).
Establishment of Aloe, Gasteria, and Haworthia Shoot Cultures from Inflorescence Explants
Authors: Richwine Arthur M. , Tipton Jimmy L. , Thompson Gary A.
Published: February 2019

Shoot cultures of Aloe, Gasteria, and Haworthia species were initiated directly from immature inflorescences. Explants placed on a modified MS medium containing 5.4 mm zeatin riboside initiated shoots within 8 to 12 weeks. Long-term shoot cultures were established and maintained on media containing either 5.4 μm zeatin riboside or 4 μm BA. Shoots easily rooted in vitro, and rooted plantlets were esablished in soil. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); 6-[4-hydroxy-3-methyl-but-2-enylamino]purine riboside (zeatin riboside).
Temperature Effects on Resistance to Meloidogyne spp. in Excised Tomato Roots
Authors: Abdul-Baki Aref A. , Haroon Sanaa A. , Chitwood David J.
Published: February 2019

Resistance to root-knot nematodes (Meloidogyne spp.) in tomato (Lycopersicon esculentum Mill.) plants has been reported to break down at soil temperatures >28C. We evaluated in vitro root explants of tomato heterozygous (Mimi), homozygous (MiMi) at the Mi locus, or lacking the Mi-1 gene for resistance to Meloidogyne incognita (Kofoid & White) Chitwood and Meloidogyne arenaria (Neal) Chitwood at 28, 31, 34, and 37C. Genotypes Ace-55 UF and Rutgers, lacking the dominant allele, were susceptible to M. incognita and M. arenaria at all temperatures. Genotypes possessing the dominant allele (heterozygous or homozygous) were equally resistant to both nematode species. The resistance level in these genotypes was maintained fully at 31C, partially maintained at 34C, and lost at 37C. Resistance in the heat-tolerant Mi-heterozygous accession CLN 475-BC1F2-265-4-19 was not different from that of the heat-sensitive genotypes. As temperature increased, the genotypes differed in their sensitivity to resistance conferred by the Mi-1 locus.
Containerized Muskmelon Transplants: Cell Volume Effects on Pretransplant Development and Subsequent Yield
Authors: Maynard Elizabeth T. , Vavrina Charles S. , Scott W. Dennis
Published: February 2019

Muskmelon (Cucumis melo L. cvs. Superstar and Mission) transplants were grown in cellular seedling trays of polystyrene or styrofoam, with individual cells ranging in volume from 7 to 100 cm3, transplanted to the field, and grown to maturity in Florida and Indiana during the 1993 and 1994 growing seasons. Seedling leaf area, shoot and root weights before transplanting, and shoot dry weight 20 days after transplanting increased linearly with increasing cell volume in Florida. Thirty days after transplanting, vine length showed significant linear and quadratic trends with respect to cell volume in Indiana. In Florida, early and total yields increased linearly as transplant cell volume increased for `Mission' in both years and for `Superstar' in 1994. In Indiana, early yields increased linearly as transplant cell volume increased for `Mission' in 1994 and for `Superstar' in both years, but cell volume did not consistently affect total yield. Transplant tray effects on early and total yield unrelated to linear or quadratic effects of cell volume occurred in both locations, but these effects were not consistent.
Transplant Depth Influences Tomato Yield and Maturity
Authors: Vavrina Charles S. , Olson Stephen M. , Gilreath Phyllis R. , Lamberts Mary L.
Published: February 2019

`Agriset', `All Star', and `Colonial' tomato (Lycopersicon esculentum Mill.) transplants set to a depth of the first true leaf and `Cobia' transplants set to a depth of the cotyledon leaves yielded more fruit at first harvest than plants set to the top of the rootball (root–shoot interface). The increase in fruit count was predominantly in the extra-large category. More red fruit at first harvest suggested that deeper planting hastens tomato maturity. The impact of planting depth diminished with successive harvests, indicating the response to be primarily a first-harvest phenomenon in tomato.
Zinc Fertilization of Avocado Trees
Authors: Crowley David E. , Smith Woody , Faber Ben , Manthey John A.
Published: February 2019

Methods for Zn fertilization of `Hass' avocado (Persea americana Mill.) trees were evaluated in a 2-year field experiment on a commercial orchard located on a calcareous soil (pH 7.8) in Ventura County, Calif. The fertilization methods included soil- or irrigation-applied ZnSO4; irrigation-applied Zn chelate (Zn-EDTA); trunk injection of Zn(NO3)2, and foliar applications of ZnSO4, ZnO, or Zn metalosate. Other experiments evaluated the influence of various surfactants on the Zn contents of leaves treated with foliar-applied materials and on the retention and translocation of radiolabeled 65ZnSO4 and 65Zn metalosate after application to the leaf surface. In the field experiment, tree responses to fertilization with soil-applied materials were affected significantly by their initial status, such that only trees having <50 μg·g–1 had significant increases in foliar Zn contents after fertilization. Among the three soil and irrigation treatments, ZnSO4 applied at 3.2 kg ZnSO4 per tree either as a quarterly irrigation or annually as a soil application was the most effective and increased leaf tissue Zn concentrations to 75 and 90 μg·g–1, respectively. Foliar-applied ZnSO4, ZnO, and Zn metalosate with Zn at 5.4, 0.8, and 0.9 g·liter–1, respectively, also resulted in increased leaf Zn concentrations. However, experiments with 65Zn applied to leaves of greenhouse seedlings showed that <1% of Zn applied as ZnSO4 or Zn metalosate was actually taken up by the leaf tissue and that there was little translocation of Zn into leaf parenchyma tissue adjacent to the application spots or into the leaves above or below the treated leaves. Given these problems with foliar Zn, fertilization using soil- or irrigation-applied ZnSO4 may provide the most reliable method for correction of Zn deficiency in avocado on calcareous soils.
Dikegulac-sodium Spray Enhances Uniform Regrowth of Murraya paniculata (L.) Jack Hedge
Authors: Kawabata Osamu , Criley Richard A.
Published: February 2019

An aqueous solution of dikegulac-sodium at 0, 2000, 4000, 6000, or 8000 mg a.i./liter was sprayed on a mature Murraya paniculata hedge as the first leaves expanded on newly developing lateral shoots after trimming. The lateral shoots from each 0.09-m2 hedge surface elongated less and the coefficient of variation (cv) decreased as the growth regulator concentration increased. Application of dikegulac-sodium at 4000 mg a.i./liter to the most distal leaf on topped, single-leader seedlings inhibited the elongation of distal shoots while it enhanced proximal shoot growth. Dikegulac-sodium spray between 4000 and 6000 mg a.i./liter to the hedge decreased apical dominance among lateral shoots and enhanced uniform regrowth without causing visible damages. The cv reduction was attributed to the growth regulator-induced weakening of apical dominance. Chemical name used: sodium salt of 2,3:4,6-bis-O-(1-methylethylidene)-α-l-xylo-2-hexulofuranosonic acid (dikegulac-sodium).
Sources of Potential Errors in the Application of Random Amplified Polymorphic DNAs in Cucumber
Authors: Staub Jack , Bacher Jeffery , Poetter Karl
Published: February 2019

The influence of tissue age, pathogen infestation, intrapopulation contamination, and polymerase chain reaction (PCR) conditions were assessed as sources of error in random amplified polymorphic DNA (RAPD) analysis. DNA from young, uninfected tissue provided the most consistent results. Plants infected with Sphaerotheca fuliginea Schl. (ex Fr.) Poll. showed variation in RAPD banding patterns compared to those of uninfected plants. Differences in banding patterns were detectable when DNA from two inbred lines were mixed at dilution ratios of ≤20:1 but not ≥50:1. Differing lots of commercially available 10× reaction buffer, MgCl2 stock solutions, and Taq DNA polymerase affected RAPD banding patterns and overall yield. For reproducibility of RAPD assays, it may be necessary to optimize reactions for specific lots of PCR reagents from either commercial or in-house sources.
A Double-flowered Geraldton Wax (Chamelaucium uncinatum Schauer) with an Anomalous Flower in the Ovary
Authors: McComb Jen A. , Newell Chris , Lullfitz George
Published: February 2019

A naturally occurring mutant of Chamelaucium uncinatum Schauer (Geraldton wax) is described. It has double flowers with the staminodes transformed into petals. Pollen is exuded from the anthers but is not deposited on the pollen presenter in a lipid droplet, which is normal for the species. An anomalous secondary flower with petals, stamens, and gynoecium is present in the ovary.
INVESTIGATION OF LEWISIA TWEEDYI SEED ANATOMY AND SEEDCOAT-IMPOSED DORMANCY
Authors: Roberts Christia M.
Published: February 2019

Lewisia tweedyi (A. Gray) Robinson is an endangered, herbaceous perennial native to the Cascade Mountains of northern Washington state and southern British Columbia. It is highly valued as an ornamental, but has a reputation for being challenging to grow and is only cultivated by alpine specialists. The better known Lewisia species, L. cotyledon, is a minor commercial crop in some areas of Europe and western North America. Lewisias are members of the Centrospermae; a linear peripheral embryo surrounds centrally located perisperm. Lewisia tweedyi seed is distinct from all other lewisias in having a fleshy appendage, or caruncle. Germination practices include stratification for an unspecified period in a garden cold frame. In addition to a long germination period, percent germination is characteristically low. A number of tests, including sowing under axenic conditions, and combinations of prechill periods and liquid N scarification were conducted. Seedcoat-imposed dormancy and germination requirements have been determined.
IN VITRO SCREENING FOR ANTHURIUM TOLERANCE TO BURROWING NEMATODE, RADOPHOLUS SIMILIS
Authors: Wang K.H. , Kuehnle A.R. , Sipes B.
Published: February 2019

Burrowing nematode, Radopholus similis, reduces flower-yield-infected anthurium fields. Genetic resistance is one alternative to chemical control of the disease in anthurium. Seventeen commercial anthurium varieties, established in vitro on anthurium nutrient medium, were inoculated with burrowing nematodes to screen for tolerance. Three months after inoculation, plant responses were compared by number of nematodes recovered and by symptom index and plant weight loss with respect to non-inoculated plants. Results show that `Mauna Kea' and `Flamingo' anthuriums are among the most tolerant, while `Ozaki' is one of the most susceptible. These results are consistent with grower field evaluation. Nematode count is positively correlated with symptom index and weight loss. The mechanism of tolerance or resistance of anthurium toward burrowing nematode is unclear. However, due to the fact that burrowing nematode is a migratory endoparasite, a preinfectional resistance or tolerance mechanism is more likely to take place.
EVALUATING CARROT CULTIVARS IN WASHINGTON THROUGH ON-FARM TRIALS AND IN-MARKET TASTING
Authors: Sorensen Erik J.
Published: February 2019

Carrots are among the most important commercial vegetable crops in Washington state. Over the past decade, production by both large-scale and small-scale growers has steadily increased. To assist these growers, a variety of carrot cultivars for fresh market and processing have been evaluated in on-farm trials and in-market tasting conducted by Washington State Univ. Cooperative Extension. In 1994, 116 entries from 16 seed companies and the U.S. Dept. of Agriculture were planted for evaluation. Imperator-, Chantenay-, Nantes-, and Kuroda-type carrots were planted in separate sections of this on-farm trial. Foliage and roots of all entries were scored at 120 days after planting. Customers at the Pike Place Market were asked to evaluate the appearance, flavor, and texture of 22 of these carrots. A majority of evaluators expressed a preference for Kuroda-type carrots. Some Nantes-type carrots also received high scores. The suitability of carrot cultivars for new products, including carrot juice and carrot chips, and nutritional levels were analyzed in a related study.
MICROPROPAGATION OF FICUS BENJAMINA L. `VARIEGATA'
Authors: Sukamto L. Agus
Published: February 2019

Shoot tip culture of Ficus benjamina L. `Variegata' produced multiple shoots on Murashige and Skoog (MS) medium with 1 μm 2,4-dichlorophenoxy acetic acid (2,4-D), 1 μm napthalene acetic acid (NAA), 1 μm benzylaminopurine (BAP), l-proline at 2 mg·liter–1, and l-glutamine at 1 mg·liter–1 without previously producing callus. Multiple shoots were more profuse on one-half MS medium with 4.44 μm BAP. Single shoot of multiple shoots produced roots on one-half MS medium with NAA at 2.69 μm. Leaf culture of the plant produced profuse calli on same media without plant regeneration. Calli subcultured on one-half MS or MS media with 1.7 μm indole-3-acetic acid (IAA) and 150 μm 6-(y,y-dimethylallylamino)-purine (2iP) did not induce plant regeneration.
GROWTH OF FOUR SOUTHWESTERN LANDSCAPE TREES IN CUPRIC-HYDROXIDE-PAINTED NURSERY CONTAINERS
Authors: Martin C.A. , Bhattacharya S.
Published: February 2019

Seedling liners of sweet acacia (Acacia smallii), shoestring acacia (Acacia stenophylla), palo brea (Cercidium praecox), and Chilean mesquite (Prosopis chilensis) were potted on 1 June 1993 into 27-liter (#5) black polyethylene containers filled with a 70% ponderosa pine forest mulch, 15% sand, and 15% silt (by volume) rooting medium. Just before potting, the inner wall of one-half of the containers of each species was painted with a latex paint impregnated with cupric hydroxide; the remaining containers were unpainted as a control treatment. Trees were then grown for 5 months in an outdoor container production nursery at a spacing distance of 45 cm. All trees were irrigated and fertilized according to standard nursery practices. The effect of cupric-hydroxide-painted containers (CHPC) on tree growth was species specific. Compared with nonpainted controls, CHPC caused roots to become more branched and decreased shoot lateral branch number and extension lengths of sweet acacia and shoestring acacia. CHPC also decreased height of shoestring acacia, but did not affect height of sweet acacia or root and shoot dry weight of sweet acacia and shoestring acacia. Shoot and root dry weight, height, and shoot lateral branch number and extension lengths of Chilean mesquite in CHPC were all increased compared with nonpainted controls. CHPC did not affect root branching of Chilean mesquite. Also, CHPC did not affect any measured growth variable of palo brea.
LIFE IN THE WORLD WIDE WEB—SPIDER OR FLY?
Authors: Belliston Jim
Published: February 2019

The Internet is a computer network phenomenon with no center and no circumference. It is a vast interconnected WEB of information resources. Historically, finding data in this WEB has been difficult, but things are improving rapidly. In this session, we will find out how to safely get around in this network of information. We will find repositories of relevance to the horticultural discipline. We will also discuss how to contribute to the information resources found on the Internet.
Peach Tree Vegetative and Root Growth Respond to Orchard Floor Management
Authors: Parker Michael L. , Meyer John R.
Published: February 2019

Peach (Prunus persica L. Batsch. `Biscoe'/Lovell) trees were grown in a sandy loam soil under six orchard floor management systems, including five vegetative covers (continuous under the tree) and a vegetation-free control (bare ground). At the end of the fifth year, trees grown in bare ground and nimblewill grass (Muhlenbergia schreberi J.F. Gmel.) had a significantly larger trunk cross-sectional area (TCSA) than trees grown in weedy plots, centipedegrass [Eremochloa ophiuroides (Munro) Hack.], or bahiagrass (Paspalum notatum Flugge). Trees grown in brome (Bromus mollis L.) did not differ significantly in TCSA from any other treatment. Soil profile excavations of the root system revealed that trees grown in bare ground or with nimblewill had significantly higher root densities than those in the weedy plots or grown with bahiagrass. Vector analysis of root distribution indicated that trees grown in bare ground or nimblewill rooted deeper than trees in all other treatments. The greatest reduction in deep rooting occurred with bahiagrass.
Azadirachtin: Potential Use for Controlling Lepidopterous Insects and Increasing Marketability of Cabbage
Authors: Leskovar Daniel I. , Boales A. Kipp
Published: February 2019

Azadirachtin (ATI), an insect growth regulator derived from extracts of neem (Azadirachta indica A. Juss) seed, was evaluated for the control of cabbage looper (Trichoplusia ni Hübner), diamondback moth (Plutella xylostella L.), and silverleaf whitefly (Bemisia argentifolii Bellows and Perring) in cabbage (Brassica oleracea L. Capitata Group) grown in southwestern Texas. In Fall 1992, ATI was tested with the a.i. at 0, 22, 33 and 44 g·ha–1. In 1993, ATI was evaluated at 33 g·ha–1 and in combination with M-Pede (1%, v/v), an organic insecticide based on potassium salts of fatty acids at 49%. Two commercial (Align and Neemix) and one experimental hydrogenated (LDF) ATI formulations were evaluated at 11 g·ha–1 in 1994. Insect populations were monitored weekly before and after treatment application. Plant damage was evaluated immediately before harvest, and marketable yields were determined. In 1992, large (>6 mm long) and total cabbage looper counts were reduced by ATI compared with the nontreated control. Insect mortality was similar for all ATI rates tested in 1992. In 1993, ATI at 33 g·ha–1 + M-Pede reduced the number of cabbage looper and diamondback moth larvae. ATI efficacy against cabbage looper and diamondback moth was enhanced when crop oil (polyol fatty acid esters with polyethoxylated derivatives) was tank-mixed with Align or LDF formulations in 1994. ATI did not reduce the number of silverleaf whitefly nymphs compared to the control. In all seasons, ATI-treated plants had lower insect-induced plant damage and higher marketable head weights than the nontreated control. Using ATI on lepidopterous pests appears to be beneficial for integrated pest management strategies.