bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Planting Depth on Growth of Young Apple Trees
Authors: Lyons C.G. , Byers R.E. , Yoder K.S.
Published: August 2020

Shallow planted trees of ‘Delicious’ apple (Malus domestica Borkh.) on Malling 7A (M 7A) and Malling-Merton 111 (MM 111) rootstock were smaller in the 5th year following planting and had higher bloom densities than deep-planted trees. Trees on MM 111 also had more fruit per cross sectional area when shallow planted. Deep planted trees of MM 111 had greater depth to the first root. No differences were observed in degree of lean of either rootstock.
Consumer Attitudes Toward the Defoliation of American Arborvitae, Thuja occidentalis, by Bagworm, Thyridopteryx ephemeraeformis
Authors: Sadof Clifford S. , Raupp Michael J.
Published: August 2020

A group of 93 retail nursery customers were surveyed to determine their attitudes toward defoliation of American arborvitae, Thuja occidentalis L., caused by the bagworm, Thyridopteryx ephemeraeformis (Haworth). More than half of the customers surveyed perceived plants with 4% of the leaf area missing or discolored as damaged. The proportion of customers who refused to buy a plant corresponded closely (r = 0.98, p < .0001) with the proportion of those who perceived the plant as damaged.
A Case for Direct Seeding of Woody Species on Highway Roadsides
Authors: Hipkins P. Lloyd , Coartney James S.
Published: August 2020

The use of woody species on highway rights-of-way is a long standing practice which is coming under closer scrutiny as costs of landscape materials and maintenance increase. Direct-seeding of woody species may be an option to help control establishment costs. The use of native species may help to reduce maintenance costs as well as the mortality experienced with exotic landscape cultivars. Past experience has shown that successful direct-seeding can be accomplished with proper site preparation and planting techniques.
Flatheaded Apple Tree Borer (Coleoptera: Buprestidae) in Nursery-Grown Red Maples: Phenology of Emergence, Treatment Timing, and Response to Stressed Trees
Authors: Potter Daniel A. , Timmons G. Mark , Gordon F. Carter
Published: August 2020

Emergence of adult flatheaded apple tree borers, Chrysobothris femorata (Olivier), from red maple (Acer rubrum L.) trees and cut bolts was monitored in central Kentucky from 1984–1986. A forecasting system based on accumulated degree-days (DD) was developed for predicting optimum treatment dates. Date of first emergence ranged from May 8 to June 6, corresponding to a mean accumulation of 412 Centigrade DD (742 F DD) calculated from a base temperature of 10°C (50°F). A single application of lindane or chlorpyrifos applied soon after adult borers began to emerge protected young red maple trees from infestation. Adult C. femorata were trapped in nurseries from May until August. Twenty-five species of adult Buprestidae representing 5 genera were attracted to experimentally stressed red maples. Although results were variable, stressed trees were generally more attractive and/or susceptible to borers.
Tolerance of Direct-Seeded Honey Locust to Preemergent Herbicides in Various Soil Types
Authors: Geyer W.A. , Long C.E.
Published: August 2020

Various soil types were seeded with honey locust (Gleditsia triacanthos L.) and treated with preemergent herbicides to determine their effect on germination, seedling survival, and growth. Tested were alachlor at 2.2 (2.0), chloroxuron at 2.2 (2.0), DCPA at 11.2 (10.0), EPTC at 4.5 (4.0), napropamide at 1.1 (1.0), oxadiazon at 4.5 (4.0) and profluralin at 0.6 (0.5) kg ai/ha (lb ai/A). Acceptable survival and growth was found for all but oxadiazon which significantly reduced survival in the sandy loam soils.
Influence of Slow-release Fertilizer Source on Growth and Quality of Areca Palm, Chrysalidocarpus lutescens Wendl
Authors: Rauch F. D. , Yahata P. , Murakami P. K.
Published: August 2020

There was little difference noted in plant growth and quality of Areca palm, Chrysalidocarpus lutescens Wendl., when treated with three levels of several slow-release fertilizers at the manufacturer's recommended rates. The two resin-coated (RC) materials 18N-2.6P-10K and 17N-3.1P-10K (18-6-12 and 17-7-12) and urea formaldehyde (UF) fertilizer 10N-4.4P-8.3K (10-10-10) resulted in significantly better growth than either the isobutyledene diurea (IBDU) 20N-2.2P-4.2K (20-5-5) or the sulfur-coated urea (SCU) 14N-6P-12K (14-14-14) fertilizer sources. The RC materials were the least expensive fertilizers used in the production of this slow growing crop.
Budset and Growth of Eastern White Pine Following Application of 6-Benzylaminopurine to Seedlings Fertilized with Different Levels of Nitrogen
Authors: Eric Hinesley L. , Wright Robert D.
Published: August 2020

Eastern white pine (Pinus strobus L.) were potted and solution fed once weekly during 2 growing seasons with 5 levels of N in the irrigation water: 50, 100, 200, 300 and 400 ppm. Leaders were treated with 750 ppm 6-benzylaminopurine (BA) in late June of the first year. The higher N levels resulted in greater stem diameter, greater foliage dry weight, longer and heavier needle fascicles, better foliage color, greater budset after application of BA, and more and longer branches on the BA-treated leader the second growing season. BA should be applied to trees with N concentration ≥ 1.5% in one-year-old foliage.
Micropropagation of Flame Azalea
Authors: Blazich Frank A. , Acedo Juan R.
Published: August 2020

Shoots tips excised from an actively growing stock plant of flame azalea [Rhododendron calendulaceum (Michx.) Torr.] were surface sterilized, the terminal portions were removed (decapitated) and the shoots placed horizontally on agar-solidified Woody Plant Medium (WPM) supplemented with 15 ppm 6-(γ, γ-dimethylallylamino)-purine (2iP). Within 4 to 6 months multiple shoot formation commenced. After 2 to 3 additional months of growth, axillary shoots were excised from the original explants. The shoots were decapitated and placed on WPM. After 2 subcultures, 8-node axillary shoots were excised, decapitated and cultured on agar-solidified WPM supplemented with 0, 4, 8, 12, 16, 24, and 32 ppm 2iP. The greatest number of shoots (microcuttings) ≥ 5 mm (0.2 in) were produced at 12 ppm 2iP. Microcuttings ≥ 10 mm (0.4 in) were rooted using ex vitro procedures. Enhancement of both axillary shoot multiplication and shoot length was achieved by addition to the medium of 80 ppm adenine sulfate and 200 ppm NaH2PO4.
Comparison of Ronstar Formulations for Efficacy and Phytotoxicity in Container Grown Landscape Plants
Authors: Kalmowitz K. , Whitwell T.
Published: August 2020

Three formulations of Ronstar [oxadiazon-2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-2-1 ,3,4-oxadiazolin-5 one], were evaluated for control of 3 weed species and injury to 3 woody landscape plants over 90 days. Wettable powder (WP) 50%, 20% granular and 0.24 kg/L (2 lb/gal) emulsifiable concentrate (EC) were evaluated at 3 rates, 2.2, 4.5 and 9.0 kg/ha (2,4 and 8 lb/A). The WP formulation was generally more effective than the G formulation for control of goosegrass [Eleusine indica (L.) Gaert] and Pennsylvania smartweed (Polygonum pensylvanicum L.). Ronstar at the 4.5 kg/ha (4 lb/A) rate of WP and EC formulations provided excellent control of goosegrass and Pennsylvania smartweed. Prostrate spurge (Euphorbia humistrata Eagelm. ex gray) was controlled only by the 9.0 kg/ha (8 lb/A) rate of all 3 formulations.

Pronounced injury to Compact Japanese Holly (Ilex crenata Thumb. ‘Compacta’) and ‘Hershey Red’ Azalea Rhododendron obtusum was evident at 14 and 30 days after treatment with the WP and EC formulations. Ninety days after treatment the species were marketable plants. Evergreen euonymus (Euonymus japonica) was not injured with any formulation or rate of Ronstar.
‘Bradford’ Pear Propagation by Softwood Cuttings
Authors: Gilliam C.H. , Dozier W.A. , Knowles J.W.
Published: August 2020

Three experiments were conducted evaluating rooting of Pyrus calleryana ‘Bradford’. Terminal cuttings rooted more easily than midsection or basal cuttings of recently matured wood. Use of 50% ethanol as a solvent for IBA resulted in reduced rooting of terminal cuttings. Supenor “quick dip” treatments identified for propagation of ‘Bradford’ pear included: KOH + 10–20,000 ppm IBA, ETOH + KOH + 10–20,000 ppm IBA, and K-IBA at 20,000 ppm IBA.
Use of Soluble Salts as an Indicator of Soil Fertility for Dieffenbachia and Dwarf Schefflera
Authors: Poole R.T. , Conover C.A.
Published: August 2020

Fifteen-cm (6 in) pots containing a peat-lite medium and no plants were leached with varying amounts of water for soluble salts (SS) analysis. Volume of water applied to pots within ranges tested was not an important factor when determining leachate soluble salts. Dieffenbachia maculata (Lodd) G. Don ‘Compacta’ and Schefflera arboricola H. Ayata (Dwarf schefflera) were fertilized with different sources and rates. Good quality Dieffenbachia were grown with a range of 2750 to 7700 kg N/ha/year (2500 to 7000 lbs/A/yr) with SS of leachate from 341 to 9750 micromhos/cm and 128 to 1243 from a 2:1 by volume method. Dwarf schefflera grew best with a range of 1100 to 6050 kg N/ha/year (1000 to 5500 lbs/A/yr) and SS of leachate from 1384 to 11796, and 2:1 extract from 159 to 1512. Level of conductivity varied considerably within treatments and was not a good indicator of desired soil fertility. Further tests showed that the pour-through method was best when percent of soil moisture varied between 33 and 100%.
Evaluation of Potato Leafhopper Injury Among Acer rubrum Progenies
Authors: Townsend A.M.
Published: August 2020

Significant variation in injury from potato leafhopper (Empoasca fabae (Harris)) was found among red maple (Acer rubrum L.) progenies grown from seed collected in 48 stands scattered throughout the species range. Both the stand of origin and one-parent families within stands were highly significant sources of variation in degree of injury. Seedlings from far northern areas generally sustained less injury than did seedlings from more southerly sources. The broad geographic pattern of injury paralleled that found in growth initiation in previous studies, and suggests that resistance to potato leafhopper injury is at least partially phenological in nature—with those trees initiating growth earliest in the spring sustaining the least injury.
Production of Pre-finished Northern Woody Plants in Florida
Authors: Ingram Dewayne L. , Zimet David , Still Steven , Kuhns Larry J.
Published: August 2020

The physiological and economic feasibility of producing pre-finished woody landscape plants normally considered restricted to northern climates in the southern states was investigated. Several years of work in Florida indicates that this production scheme is feasible for Ilex × meserveae S.Y. Hu ‘Blue Prince’, Viburnum opulus L., V. × juddii Rehd. and Berberis thunbergii DC. ‘Crimson Pigmy’. Euonymus alata Thunb. ‘Compacta’, Acer rubrum L., Magnolia × soulangiana Soul. -Bod. and Hamamelis virginiana L. were not viable candidates under production practices considered to date. The estimated costs for producing these plants in 930 cm3 (1 qt) containers is $0.66, with about 38% of this cost associated with labor.
Influence of Light and Temperature on Seed Germination of Flame Azalea
Authors: Malek Asiah A. , Blazich Frank A. , Warren Stuart L. , Shelton James E.
Published: August 2020

Seeds of flame azalea [Rhododendron calendulaceum (Michx.) Torr.] were germinated at 25°C (77°F) and 25°/15°C (77°/59°F) with daily photoperiods of 0, ½, ½ twice daily, 1, 2, 4, 8, 12 and 24 hr. Seeds exhibited an obligate light requirement. At 25°C (77°F), increasing photoperiods increased germination with maximum germination (85%) occurring by day 12 under continuous illumination. The alternating temperature of 25°/15°C (77°/59°F) enhanced germination when light was limiting. At this temperature, maximum germination of 84 to 91% was reached by day 24 for all photoperiods ≥½ hr although at photoperiods ≥4 hr, comparable germination was noted at day 18.
Phytotoxicity and Yellow Nutsedge Control in Azalea and Liriope with Basagran (bentazon)
Authors: Derr Jeffrey F. , Appleton Bonnie Lee
Published: August 2020

Tolerance of eight azalea cultivars and three liriope cultivars to two broadcast applications of Basagran at 1.1 and 2.2 kg/ha (1.0 and 2.0 lb/A) was determined in container studies. No injury was observed on azalea cultivars ‘Rosebud’, ‘Tradition’, ‘Delaware Valley White’ or ‘Elsie Lee’ 40 days after the second application of Basagran at 2.2 kg ai/ha (2.0 lb/A) plus crop oil. This treatment injured ‘Hershey's Red’ and ‘Girard's Rose’, but two applications of Basagran at 2.2 kg/ha applied alone or at 1.1 kg/ha (1.0 lb/A) with or without crop oil did not injure these two varieties. Slight injury (16%) was observed on ‘Corsage’ 20 days after the second application of Basagran at 1.1 kg/ha (1.0 lb/A), although no injury was seen with other treatments. Greater injury (22 to 35%) occurred to ‘Pleasant White’ 20 days after treatment when Basagran was applied twice at 1.1 or 2.2 kg/ha (1.0 or 2.0 lb/A) with or without crop oil. Injury to all azalea cultivars decreased with time, with no injury apparent 70 days after treatment. Greater injury (22 to 27%) was observed in variegated than green liriope or Liriope spicata (8 to 13%) 20 days after the second application of Basagran at 1.1 or 2.2 kg/ha (1.0 or 2.0 lb/A) with or without crop oil. Addition of crop oil improved the control of yellow nutsedge with Basagran at 1.1 or 2.2 kg/ha (1.0 or 2.0 lb/A).
Effect of Selected Pruning Methods to Obtain Straight Trunks on Container Grown Quercus shumardii Buckl.
Authors: Laiche Adolph J.
Published: August 2020

Quercus shumardii seedling trees in 7.6 1 (2 gal) containers were selected with straight and crooked trunks and planted in 26 1 (7 gal) containers on March 13, 1987. Pruning treatments to trees with straight and crooked trunks were: (A) not pruned; (B) lower lateral branches on the trunk headed back; and trunks severed at 5 cm (2 in) on (C) March 30, 1987 or (D) May 13, 1987 with lower lateral branches arising on the forced new trunk headed back. Trees were allowed to branch normally above 91 cm (3 ft). The study was terminated October 19, 1987.

Tree height and trunk quality of trees with straight trunks were not improved by pruning treatments. Height of trees with crooked trunks was not reduced by heading back laterals only, or by severing trunks on March 30, 1987. Trunk quality of trees with crooked trunks was substantially improved by all pruning treatments, although the resultant trunk quality was not equal to that of trees with straight trunks. Severing trunks 5 cm (2 in) above the growth medium and heading back lateral branches on the lower trunk reduced caliper and the number of branches above 91 cm (3 ft). Delaying severing of trunks approximately 6 weeks after bud break caused a further reduction of trunk caliper.
Rooting Response of Photinia × fraseri Dress ‘Birmingham’ to 25 Carrier and Carrier Plus IBA Formulations
Authors: Dirr Michael A.
Published: August 2020

Twenty-five carriers (solvents) either separately or in combination with IBA were tested for effectiveness in promoting rooting of Photinia × fraseri ‘Birmingham’, Fraser photinia. Maximum rooting percentages, root numbers and lengths resulted from carrier plus IBA solutions, although 95% ethanol produced 87% rooting. IBA plus 95 and 50% ethanol, 20 and 10% polyethylene glycol (PEG), 20 and 1% dimethyl sulfoxide (DMSO) produced the highest rooting percentages, root numbers and lengths. K-IBA and water was largely ineffective, suggesting that carriers enhanced the effect of the K-IBA. Twenty percent (20%) formulations of PEG, DMSO, and N,N-dimethylformamide (DMF) without IBA improved rooting response compared to 10 and 1% concentrations. The lack of effectiveness of K-IBA and water, and the relative effectiveness of higher rates of PEG, DMSO, and DMF without IBA suggest that carriers may have a significant effect on rooting with or without IBA.
Susceptibility of Lilacs to Mycoplasmalike Organisms
Authors: Hibben C.R. , Franzen L.M.
Published: August 2020

The cause of lilac witches'-broom has been identified as a mycoplasmalike organism (MLO). From field symptoms and the detection of MLO in the phloem by fluorescence microscopy, Syringa vulgaris cultivars were identified as susceptible but more tolerant of infection than non-vulgaris lilacs. The MLO were graft-transmissible but not seed-transmissible. Mycoplasmal infection has been identified in the following lilac species and hybrids: S. × diversifolia, S. × henryi, S. henryi × tomentella, S. × josiflexa, S. josikaea, S. julianae, S. komarowii, S. laciniata, S. meyeri, S. microphylla, S. × nanceiana, S. oblata var. dilatata, S. × persica, S. × prestoniae, S. sweginzowii, S. villosa, S. villosa × sweginzowii, S. vulgaris, and S. yunnanensis.
Paclobutrazol Inhibits Growth of Woody Landscape Plants
Authors: Keever G.J. , Foster W.J. , Stephenson J.C.
Published: August 2020

Paclobutrazol, applied as a spray or drench, suppressed growth of 8 woody landscape species. Magnitude of growth inhibition was directly correlated with application rate, whereas both magnitude and duration of growth inhibition was influenced by application method. Generally, paclobutrazol when applied as a drench suppressed growth to a greater degree than did spray applications. Flowering or fruiting of 3 species was generally promoted with paclobutrazol, while phytotoxicity symptoms were observed on 4 species.
Evaluation of Dinitroaniline Herbicides for Weed Control in Container Landscape Plant Production
Authors: Stamps Robert H. , Neal Catherine A.
Published: August 2020

Five formulations of three dinitroaniline (DNA) herbicides [Surflan (oryzalin); Pre-M, Southern Weedgrass Control (pendimethalin); and Barricade (prodiamine)] were applied at 4.48 kg ai/ha (4.0 lb ai/A) every four months to container-grown landscape plants. These treatments were compared with untreated and weed-free controls, as well as the combination herbicides Rout and Ornamental Herbicide 2 composed of oryzalin or pendimethalin, respectively, [1.12 kg ai/ha (1.0 lb ai/A)] with Goal (oxyfluorfen) [2.24 kg ai/ha (2.0 lb ai/A)]. The combination herbicides caused the greatest amount of acute phytotoxicity, severely damaging Hemerocallis hybrid ‘Aztec Gold’ and Liriope muscari ‘Big Blue’. Water dispersable granular formulations of Pre-M (pendimethalin) and Barricade (prodiamine) were phytotoxic to Photinia × fraseri while the granular formulations were not. Surflan (oryzalin) caused the greatest reduction in crop growth and was the only treatment that reduced survival. Surflan (oryzalin) and Ornamental Herbicide 2 (pendimethalin + oxyfluorfen) inhibited daylily flowering 98% and 65%, respectively. Hairy bittercress (Cardamine hirsuta), spotted spurge (Chamaesyce maculata), and yerba-de-tago (Eclipta alba) control generally was best with Barricade (prodiamine) and treatments containing Goal (oxytluorfen). All herbicides, except Surflan (oryzalin), reduced weed biomass after two herbicide applications. All herbicides provided significant weed control after three applications.
Rooting of American Chestnut Microcuttings
Authors: Serres Rod , Read Paul , Hackett Wesley , Nissen Per
Published: August 2020

A procedure for micropropagation of American chestnut (Castanea dentata (Marsh.) Borkh.) seedlings was devised and three factors affecting in vitro rooting were investigated. A two-step rooting procedure is utilized with a short term exposure to the auxin, IBA (indole-3-butyric acid), called the pulse treatment followed by transfer to an auxin-free medium called the rooting treatment. Optimum rooting was attained with an IBA concentratIon of 369 μM, a sucrose concentration of 4% (w/v) and half strength WPM basal medium concentration. This rooting regimen should enhance vegetative propagation techniques needed for rapid multiplication of selected disease-resistant trees.
Propagation of Heptacodium jasminoides Airy-Shaw by Softwood and Semi-hardwood Cuttings
Authors: Lee Chin Chin , Bilderback T.E.
Published: August 2020

Softwood and semi-hardwood two node cuttings of Heptacodium jasminoides from basal and middle stem sections rooted better than terminal sections. Basal and middle softwood cuttings exhibited greater rooting (65 and 55% resp.) than terminal cuttings (42%). Basal softwood cuttings produced more roots (7.0) than terminal cuttings (3.8). Root length and rootball diameter were not different among the three cutting positions. Semi-hardwood basal cuttings produced an average of 53.5 roots, while middle and terminal cuttings produced 25.8 and 19.7, resp. Cuttings treated with the potassium salt formulation of indolebutyric acid (K-IBA) exhibited increased rooting, greater root number and length, and greater rootball diameter in softwood cuttings. Semi-hardwood cuttings treated with K-IBA rooted in higher percentages and produced more roots than untreated cuttings.
Growth Response of Podocarpus and Ligustrum to VA Mycorrhizae and Fertilizer Rate
Authors: Yeager T.H. , Johnson C.R. , Schenck N.C.
Published: August 2020

Container-grown Podocarpus macrophyllus (Thunb.) D. Don and Ligustrum japonicum Thunb. inoculated or noninoculated with the mycorrhizal fungus Glomus intraradices Schenck & Smith were fertilized with Lesco 20N-2.6P-10K (20-6-12) at either 0, 4.3, 8.6, 17.3 or 34.6 g (0, 0.15, 0.30, 0.60 or 1.20 oz) per 6-l (#2) container. Plants were fertilized at potting and again 3.5 months later for each of 2 consecutive applications. Seven months after potting, P. macrophyllus shoot dry weights were greater for noninoculated than inoculated plants when fertilized with the manufacturer's recommended fertilizer rate of 17.3 g per container. L. japonicum shoot dry weights were not different due to inoculation at the 17.3 g fertilizer rate. Mean heights for P. macrophyllus were greater for the inoculated than noninoculated plants and plants fertilized with one-half the recommended fertlizer rate (8.6 g) were ranked superior to noninoculated P. macrophyllus receiving the manufacturer's recommended rate (17.3 g). One year after plants were transplanted to a simulated landscape, P. macrophyllus and L. japonicum shoot dry weights were not different due to inoculation.
Overwintering Container-grown Herbaceous Perennials in Northern Regions
Authors: Perry Leonard P.
Published: August 2020

A 3 year study was initiated to evaluate the survival of several species of container-grown herbaceous perennials with various overwintering techniques. Although species reacted individually to overwintering covers, those with white reflective surfaces generally provided adequate protection. Straw, non-reflective Plantfoamss™, or no cover usually resulted in large losses. Container medium temperatures were 4° to 7°C (8° to 15°F) degrees warmer than surrounding air temperatures, with a “sandwich” of 30 cm (1 ft ) fluffed oat straw between layers of white polyfilm providing the least medium temperature fluctuation (3°C or 6°F with ambient fluctuation of 16°C or 34°F), and the most temperature moderation (1°C or 34°F with ambient −16°C or 3°F). Uncovering plants later than the first week in April occasionall y resulted in plant losses.
Tolerance of Leyland Cypress and Red-Tip Photinia to Soil and Foliar Applied Sodium Chloride
Authors: Dirr Michael A.
Published: August 2020

NaCl at 0.15 N was applied 3 times per week as a soil drench or foliar spray to established container-grown plants of Leyland cypress [× Cupressocyparis leylandii (A. B. Jacks. & Dallim.) Dallim. & A. B. Jacks.] and red-tip photinia (Photinia × fraseri Dress ‘Birmingham’). Soil-salt applications were more injurious than spray applications. Leyland cypress did not develop necrosis, but dry weights of plants drenched with salts were reduced. Photinia leaves were necrotic in both salt treatments but dry weight was reduced only with plants receiving soil salts. Tissue Na levels did not reflect the degree of injury while Cl levels correlated with injury. Leyland cypress displayed high salt tolerance and red-tip photinia low tolerance.
Control of Basal Sprout Regrowth on Crapemyrtle with NAA
Authors: Keever Gary J. , Foster William J.
Published: August 2020

Inhibition of basal sprout development on Lagerstroemia indica L. × fauriei Koehne ‘Natchez’ and L. indica L. ‘Country Red’ was achieved with 1-naphthaleneacetic acid (NAA) applied as a directed trunk spray or in a lanolin paste. A directed trunk spray was more effective than lanolin paste application in reducing sprout number and dry weight; plant height of ‘Country Red’, but not ‘Natchez’ crapemyrtle, was reduced by spray application compared to lanolin paste application or the control. Sprout number and dry weight of both crapemyrtle cultivars, shoot dry weight of both cultivars sprayed, and plant height of sprayed ‘Country Red’ crapemyrtle decreased with increasing NAA rate. NAA rate did not affect shoot dry weight of either cultivar or height of ‘Country Red’ crapemyrtle treated with NAA in a lanolin paste. Height of ‘Natchez’ crapemyrtle treated by either method of application was not affected by NAA rate.
Anthracnose of Piggyback Plant Caused by Colletotrichum gloeosporioides (Penz.) Sacc.
Authors: Pierce Luellen , McCain A.H.
Published: August 2020

A leaf spotting disease of Tolmiea menziesii Torr. & Gray (piggyback plant) caused by Colletotrichum gloeosporioides (Penz.) Sacco was investigated. The disease requires a moisture period of at least 12 hours for symptoms to occur. The disease is severe at 15.5, 21, and 27°C, (60, 70, 80°F), but does not occur at 32°C (90°F). Daconil and Fore are effective fungicidal controls.
Effects of Application of Benzyladenine to Seedlings of Pinus sylvestris and Pinus nigra
Authors: Boe A.A.
Published: August 2020

Greenhouse grown seedlings of Pinus sylvestris L. (Scots pine) and Pinus nigra Arnold. (Austrian pine) were treated with plant growth regulators in a 1% solution of dimethyl sulfoxide. Benzyladenine (BA) induced branching of seedlings of Scots pine. Both Scots pine and Austrian pine seedlings were reduced in height by BA treatments. The addition of gibberellic acid (GA) to the BA treatments had little effect on branching or seedling height. After a second growth cycle the Scots pine seedlings treated with BA were shorter and had more branches while the Austrian pine seedlings were also shorter without an increase in the number of branches.
Herbicide Use In Propagation: Effects on Rooting and Root Growth of Stem Cuttings
Authors: Thetford Mack , Gilliam Charles H.
Published: August 2020

Two experiments were conducted to determine the effects of several preemergence applied herbicides on rooting, root quality and subsequent root growth of selected woody cuttings. In the first experiment Ilex × attenuata Ashe ‘Fosteri’ rooting percentage, primary root numbers and root ratings were suppressed with Surflan (oryzalin). In the second experiment, the long-term effects of herbicide use in propagation were monitored for 13 months after potting. Suppression of one or more rooting variables occurred with the 3 species, Abelia X grandiflora ‘Sherwoodii’, Buxus microphylla var. koreana, and Ilex crenata ‘Compacta’, 8 weeks after cuttings were placed in propagation. Thirteen months later, Surflan treated boxwood exhibited root and shoot growth suppression while ‘Compacta’ holly exhibited suppressed root growth.
Evaluation of Landscape Fabrics in Suppressing Growth of Weed Species
Authors: Martin Chris A. , Ponder Harry G. , Gilliam Charles H.
Published: August 2020

Two tests were conducted to evaluate weed penetration up through landscape fabrics. The degree of weed suppression varied depending on the specific landscape fabric. No landscape fabric gave total suppression of weeds tested. Sicklepod (Cassia obtusifolia L.) and smallflower morningglory (Jacquemontia tamnifolia (L.) Grisebach.) were inhibited by all landscape fabrics. Growth of pigweed (Aranthus sp.), bermudagrass (Cynodon datylon (L.) Persoon.), yellow nutsedge (Cyperus esculentus L.), and johnsongrass (Sorghum halepense (L.) Persoon.) was suppressed by certain landscape fabrics.
Effects of Banding and IBA on Rooting and Budbreak in Cuttings of Apple Rootstock ‘MM.106’ and Franklinia
Authors: Sun Wen-Quan , Bassuk Nina L.
Published: August 2020

Banding with Velcro™ of new shoot growth in moderately difficult-to-root apple rootstock MM.106 (Malus domestica Borkh.) for 7 days prior to taking cuttings, and treatment of cuttings with 500 to 2000 ppm indolebutyric acid (IBA) increased both percent rooting and root number. Banding, however, did not influence the rooting of easy-to-root Franklinia alatamaha Marsh. IBA at 0 to 1000 ppm induced a logarithmic increase in percent rooting of cuttings of MM.106 and root number of cuttings of Franklinia; but, higher levels of IBA reduced both. Banding prevented the rooting inhibition found at high concentrations of IBA in cuttings of MM.106, while simultaneously stimulating lateral budbreak and greater root number. Stem banding improved the establishment of cuttings treated with 1000 ppm and 2000 ppm IBA. Without banding, establishment of these cuttings was markedly decreased.
Growth of Perennials and Leaching of Heavy Metals in Media Amended with a Municipal Leaf, Sewage Sludge and Street Sand Compost
Authors: Bugbee G.J. , Frink C.R. , Migneault D.
Published: August 2020

Municipal leaves, sewage sludge, and street sand were composted by a modified Beltsville aerated pile technique. Rooted cuttings of Aster novi-belgii L. ‘Peter Harrison,’ Gaura Lindheimeri Engelm. & A. Gray and Sedum purpurem (L.) Link ‘Autumn Joy’ were grown for 4 months in 2 1 (2 qt) containers filled with media containing 0, 10, 30, 60, 80 and 100 (percent by vol) compost. The medium with 0% compost contained loamy sand topsoil, peat, sand and Styrofoam pellets (1:5:2:2 by vol). The pH of all media was between 6.0 and 7.0. Half the containers in each treatment received liquid fertilization in mid-season and half did not. Leachate from the containers was collected at monthly intervals and analyzed for the heavy metals Cd, Cr, Cu, Mn, Ni, Pb and Zn to determine their potential for leaching.

Growth of perennials was equal or greater in all media containing compost, compared to the medium containing no compost. Liquid fertilizer further improved growth. Adding compost increased media aeration, available plant nutrients and heavy metals and decreased moisture retention and bulk density. Heavy metal concentrations in leachate were low, probably due to the near neutral media pH, and not likely to pose an environmental risk.
Effect of Potassium Level on Severity of Drechslera Leaf Spot of Calathea picturata ‘Vandenheckei’
Authors: Chase A.R. , Broschat T.K.
Published: August 2020

Severity of Drechslera leaf spot (Drechslera setariae) of Calathea picturata ‘Vandenheckei’ was affected by potassium fertilization rate with ½, 1 or 2 times the recommended rate (1400 g/m3) causing a reduction in number of lesions caused by Drechslera setariae compared to plants receiving no potassium. In addition, plant quality, height and number of leaves were unaffected by potassium rate during the test period. Leachate electrical conductivity was unaffected by these potassium rates and was approximately 1000 μhos/cm two months after fertilization.
Pin Oak Root Injury from Soil Acidification with Sulfuric Acid
Authors: Watson Gary W. , Kupkowski Gary , von der Heide Kerstin
Published: August 2020

Sulfuric acid soil treatments that have been used to reduce soil pH in the landscape can cause root damage. When 5 cm (2 in) diameter holes were filled with 33% (4 N) sulfuric acid, pH reduction of one-half unit or greater was limited to soil within 5 cm (2 in) of the treatment hole and persisted less than 2 years. Fine root density was significantly reduced and root tip injury was significantly increased within 15 cm (6 in) of the treatment hole. Cambium of woody roots greater than 3 mm (0.1 in) diameter was killed up to 25 cm (10 in) from the application hole. Destruction of the cambium would result in the death of the roots beyond the point of cambium injury and may be responsible for crown dieback which sometimes develops following acid treatments in the landscape.
Evaluation of Media Consisting of a Cotton Waste for the Production of Tropical Foliage Species
Authors: Wang Yin-Tung
Published: August 2020

Media consisting of composted cotton waste (CW) alone and CW in combination with bark or peat moss or both were evaluated for producing two tropical foliage species. Asian bell tree (Radermachera sinica (Hance) Hemsl.) grew satisfactorily in media with 25% or 50% CW, but had less dry weight when produced in CW-amended media with 50% bark. Australian umbrella tree (Brassaia actinophylla Endl.) had less dry weight when produced in media having 50% or more CW. Australian umbrella tree responded the most favorably to the medium containing 25% CW, 50% bark and 25% peat moss which resulted in the poorest Asian bell tree. Plant response to media consisting of CW appeared to be species dependent. Although there were differences in the initial pH of leachates collected from potting media, the differences were small at the termination of this experiment. The electrical conductivity of the leachate varied considerably among various media.
Influence of End-of-day Red and Far-red Light on Potted Roses
Authors: Clark D.G. , Kelly J.W. , Decoteau D.R.
Published: August 2020

The effects of end-of-day red and far-red light on postharvest leaf chlorosis of potted roses were investigated. Rosa × hybrida L. ‘Meijikatar’ (Tradename: Orange Sunblaze) and ‘Confection’ plants were treated with 30 minutes of red light (600–700 nm) or far-red light (700–780 nm) at the end of each daily photoperiod throughout production. At harvest, plants were placed in storage for 5 days at 16°C (61°F). ‘Meijikatar’ plants treated with end-of-day far-red light had more leaf chlorosis than plants treated with end-of-day red light or those which served as controls. ‘Confection’ plants treated with end-of-day far-red light had more leaf chlorosis than plants treated with end-of-day red light. ‘Meijikatar’ plants were treated in the greenhouse at the end of each photoperiod with 1 hour of incandescent or fluorescent light, with control plants receiving natural greenhouse end-of-day light, and then placed into storage. Plants treated with end-of-day incandescent light were taller than plants treated-with end-of-day fluorescent light or controls. After simulated storage, plants treated with end-of-day incandescent light had the most etiolated shoots. Light treatments had no significant effect on the amount of leaf chlorosis 5 days after removal from simulated storage.
Biology and Management of the Eugenia Psyllid (Trioza eugeniae Froggatt)
Authors: James Downer A. , Koehler Carlton S. , Paine Timothy D.
Published: August 2020

Management and biological studies were conducted on eugenia psyllid (Trioza eugeniae Froggatt) in California landscapes and at the University of California, Riverside (UCR) in 1989 and 1990. Eugenia psyllid females reproduced the year around in Ventura, California, and laid an average of 119 eggs per female at UCR. Shoot length and number of shoots after pruning were increased when an efficacious pesticide was applied at the time of pruning. Mavrik (fluvalinate) and Tame (fenpropathrin) provided excellent control of adult psyllids and were associated with increased quality of eugenia foliage. Sevin (carbaryl), Diazinon (diazinon), and Orthene (acephate) were not as effective as the pyrethroids in controlling this insect. Superior oil and Insecticidal soap did not control eugenia psyllid. Pruning as a treatment on individual shrubs was not an effective control of the insect, while pruning of an entire hedge was associated with dramatic decreases of psyllids.
Influence of Container Design on Root Circling, Top Growth, and Post-Transplant Root Growth of Selected Landscape Species
Authors: Warren Stuart L. , Blazich Frank A.
Published: August 2020

‘Delaware Valley White’ azalea, ‘Green Luster’ holly, ‘Plumosa Compacta Youngstown’ juniper, and ‘Shasta’ viburnum were grown for 1 to 2 years in four container designs: a conventional straight-walled round container, a square container with corner holes, a round container with stepped-pyramid profiles, and a poly bag. Poly bag, square, and stepped-pyramid containers significantly reduced root circling on all species compared to the traditional straight-walled round container. There were no significant differences in root circling among the three designs. Top growth was harvested at the end of 1 and 2 years. Effect of container design on top dry weight was species dependent. Poly bag, square, and stepped-pyramid containers increased top growth by 11 to 23% compared to the straight-walled round container. However, no one design was consistently superior for 2 years compared to the straightwalled round container. In addition, three of four species did not respond to container design l out of 2 years. Plants were transplanted into the landscape after growing for 1 or 2 years in the containers. After 16 weeks in the landscape, ‘Green Luster’ holly initially grown in poly bag, square, and stepped-pyramid containers had greater new root dry weight and smaller shoot (top):root ratios compared to the straight-walled round container. Top and new root dry weight of ‘Shasta’ viburnum were significantly affected by container design. However, the shoot:root ratios were not significantly different compared to the straight-walled round container. In the landscape, container design did not significantly affect top dry weight, new root dry weight or shoot:root ratio of ‘Plumosa Compacta Youngstown’ juniper.
Herbicide Tolerance of Selected Ericaceous Species
Authors: Skroch W.A. , Warren S.L. , Gallitano L.B.
Published: August 2020

This study was conducted to determine the tolerance of seven Ericaceous species to 15 herbicide treatments. Treatment response was species dependent. Pre-M (pendimenthalin) at the 2.2 kg/ha (2 lb ai/A) rate reduced top fresh weight of mountain laurel (Kalmia latifolia), flame azalea (Rhododendron calendulaceum) and Carolina rhododendron (Rhododendron carolinianum) while the 4.5 kg/ha (41b ai/A) rate affected these 3 species plus drooping leucothoe (Leucothoe fontanesiana), sourwood (Oxydendrum arboreum), Catawba rhododendron (Rhododendron catawbiense) and azalea ‘Hinocrimson’ (Rhododendron ‘Hinocrimson’). SWGC (pendimethalin) at 3.4 kg/ha (3 lb ai/A) reduced top fresh weight of sourwood, flame azalea and Carolina rhododendron. Goal (oxyfluorfen) + AG98 reduced fresh weight of every species except Carolina rhododendron. Snapshot DF (isoxaben + oryzalin) at 3.4 kg/ha (3 lb ai/A) reduced top fresh weight of mountain laurel and flame azalea. Mountain laurel showed a reduction in fresh weight for Pennant GR (metolachlor) at the 4.5 kg/ha (4 lb ai/A) rate. At the 2.2 kg/ha (2 lb ai/A) rate of Ronstar WP (oxadiazon), reduced Catawba rhododendron top fresh weight, however, Catawba rhododendron was not affected by the 4.5 kg/ha (4 lb ai/A) rate. The Poast (sethoxydim) treatment at 0.6 kg/ha (0.5 lb ai/A) + crop oil concentrate reduced fresh weight of flame azalea. SWGC at 3.4 kg/ha (3 lb ai/A), OH2 (oxyfluorfen + pendimethalin) at 3.4 kg/ha (3.0 lb ai/A), Gallery (isoxaben) at 1.1 kg/ha (1.0 lb ail A), Snapshot GR (isoxaben + trifluralin) at 4.0 kg/ha (3.75 lb ai/A), Derby (metolachlor + simazine) at 5.7 kg/ha (5.0 lb ai/A), and the ready-to-use formulation of sethoxydim did not reduce top fresh weight of any of the seven species tested.
Ozone-Induced Acceptability of Yellow-Poplar and Black Cherry to Gypsy Moth Larvae
Authors: Endress Anton G. , Jeffords Michael R. , Case Laurie J. , Smith Lane M.
Published: August 2020

The feeding behavior of 3rd instar gypsy moth (Lymantria dispar L. [Lepidoptera: Lymantriidae]) was examined on foliage from black cherry (Prunus seratina L.) and yellow-poplar (Liriadendran tulipifera L.) seedlings exposed to 71 ± 31, 212 ± 37, and 337 ± 31 μg m−3 ozone (O3) for 70 hours to gauge the effect of O3 stress on host acceptability. Normally, black cherry is a suboptimal food source and yellow-poplar is unacceptable. With feeding preference assays conducted in the laboratory using feeding arenas, the leaf area consumption of black cherry control foliage (exposed to ambient air containing 71 μg m−3 O3) by starved larvae was approximately twice that of yellow-poplar control foliage during the first 4 hours. By 8 hours, the leaf area consumed was the same for both species. O3-treated leaves of both species were preferred by the larvae relative to leaves exposed to ambient concentrations. The effect was pronounced for yellow-poplar, where consumption of ozonated foliage was more than twice that of the control, and its acceptability was enhanced to a level approximating that of black cherry.
Soil Moisture Uptake by Green Ash Trees After Transplanting
Authors: Watson Gary W. , Kupkowski Gary
Published: August 2020

Forty-five Summit green ash trees (Fraxinus pennsylvanica Marsh. ‘Summit’) were planted on a compacted clay soil site. Unamended soil, amended soil, and friable topsoil were used as backfill, in combination with holes slightly larger than the root ball, twice, and 3 times the diameter of the root ball. Soil moisture tension (SMT) was monitored in the root ball, in the backfill, and outside of the planting hole. Soil moisture tension reached at least −50 KPa within the root ball in as little as two days. Improved backfill soil and large planting holes resulted in earlier significant uptake of soil moisture outside of the root ball compared to nearby soil where roots were excluded. SMT inside the root ball were significantly more negative than the surrounding soil for all treatments until twenty weeks after transplanting. At 68 weeks after transplanting, differences in SMT between the root ball, the backfill, and the soil outside the planting hole became insignificant for all treatments. Soil moisture tensions levels reported to inhibit root growth were frequently measured in the root zone throughout the first two growing seasons after transplanting.
Can Growth of Seed-propagated Oaks be Predicted before Lining out in Nursery Rows?
Authors: Harris J. Roger , Richardson-Calfee Lisa E.
Published: August 2020

Growth rates of nursery-grown oaks (Quercus L.) vary considerably, and many oak species are not commonly grown because of slow growth when young. A method for rapid screening of young oak seedlings to predict potential growth in a production nursery was investigated. Acorns from single maternal trees of four Virginia-native oak species, Quercus montana Wild. (chestnut oak), Quercus palustris Münchh. (pin oak), Quercus velutina Lam. (black oak), and Quercus alba L. (white oak) were collected in Blacksburg, VA, in the fall of 1999 and subjected to stratification (moist-chilling) at 5C (41F). Single acorns were then planted in individual cells of 50-cell liner trays and grown in a heated greenhouse until individual seedlings had set first buds. Height at first budset was recorded for individual seedlings. Trees were then transplanted into 3.8 liter (#1) black plastic containers and grown outdoors in Blacksburg, VA, until June 2001, when they were transplanted to field soil. All trees were grown in the ground for three additional growing seasons, and final trunk diameters were measured in February 2004. Height at first budset was not related to trunk diameter at the end of the experiment for any species and was only weakly related to final height for black oak. Trunk diameter of seedlings when planted in field beds 1.5 years from seed was related to trunk diameter at the end of the experiment for all species, but little variation was explained by the relationship for chestnut oak or black oak. Plant height at field planting was not as predictive as trunk diameter for final trunk diameter, except for black oak. The utility of screening a group of oak seedlings at the liner stage for subsequent growth potential is species-specific. Screening white oak by trunk diameter appears especially promising.
Performance of Five Models to Predict the Naturalization of Non-Native Woody Plants in Iowa
Authors: Kapler Emily J. , Widrlechner Mark P. , Dixon Philip M. , Thompson Janette R.
Published: August 2020

Use of risk-assessment models that can predict the naturalization and invasion of non-native woody plants is a potentially beneficial approach for protecting human and natural environments. This study validates the power and accuracy of four risk-assessment models previously tested in Iowa, and examines the performance of a new random forest modeling approach. The random forest model was fitted with the same data used to develop the four earlier risk-assessment models. The validation of all five models was based on a new set of 11 naturalizing and 18 non-naturalizing species in Iowa. The fitted random forest model had a high classification rate (92.0%), no biologically significant errors (accepting a plant that has a high risk of naturalizing), and few horticulturally limiting errors (rejecting a plant that has a low risk of naturalizing) (8.7%). Classification rates for validation of all five models ranged from 62.1 to 93.1%. Horticulturally limiting errors for the four models previously developed for Iowa ranged from 11.1 to 38.5%, and biologically significant errors from 4.2 to 18.5%. Because of the small sample size, few classification and error rate results were significantly different from the original tests of the models. Overall, the random forest model shows promise for powerful and accurate risk-assessment, but mixed results for the other models suggest a need for further refinement.
Differences in Seed Set and Fill of Cultivars of Miscanthus Grown in USDA Cold Hardiness Zone 5 and Their Potential for Invasiveness
Authors: Madeja Glen , Umek Lauren , Havens Kayri
Published: August 2020

Miscanthus sinensis Andersson has become a very popular ornamental grass used in a variety of horticultural settings, yet in many states it now appears on invasive species lists. Many cultivars have been released with a range of different characteristics that likely increase or decrease their invasive potential in different climates. To determine the fecundity, and by extension, the invasive potential of cultivars currently sold in USDA cold hardiness Zone 5, thirty-one cultivars of M. sinensis (Maiden grass, Chinese silver grass) along with one Miscanthus subspecies cultivar (M. sinensis Andersson subsp. condensatus (Hack.) T. Koyamama ‘Cabaret’), one Miscanthus hybrid (M. × giganteus J.M. Greef & Deuter ex Hodk. Renvoize), and one related species (M. sacchariflorus (Maxim.) Hack.) were transplanted into a common garden at the Chicago Botanic Garden in Cook County, IL, and evaluated for flowering, growth habit, and seed viability. Over the course of the 5-year trial period, 68.1% of all plants survived. Growth in clump size varied greatly among taxa, as did flowering periods. Most cultivars set filled seed, ranging from 14 to 349,327 seeds per plant; only four produced no seed over the course of the trial. Most cultivars of the species represent a high risk for self-seeding in Zone 5. Because Miscanthus sinensis is self-incompatible (8), risk of self-seeding increases when two or more cultivars are grown together. Implications for potential invasiveness are discussed.