bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficacy of preemergence herbicides over time
Authors: Altland James E. 
Published: August 2020

AbstractPreemergence herbicides are applied to container-grown nursery crops repeatedly throughout the year, often in 8 to 10 week intervals. Preemergence herbicide efficacy may decline over time, resulting in reduced weed control several weeks after application if weed seed density remains high. The objective of this research is to evaluate efficacy of preemergence herbicides on creeping woodsorrel (Oxalis corniculata L.) and flexuous bittercress (Cardamine flexuosa With.) by applying weed seed from 0 to 10 weeks after herbicide application. Granular formulations of pendimethalin, prodiamine + isoxaben, oxyfluorfen + pendimethalin, and flumioxazin were applied at their maximum labeled rates to separate groups of containers every two weeks for ten weeks. After the herbicide application at 10 weeks, 40 seeds of creeping woodsorrel and flexuous bittercress each were applied to all containers. All herbicides provided effective control when seed were applied within 2 weeks of herbicide application. Herbicides containing oxyfluorfen or flumioxazin provided effective preemergence bittercress and creeping woodsorrel control when seed were applied up to 8 to 10 weeks after herbicide application. Other herbicide products resulted in reduced control as the time between herbicide and seed application increased.Index words: weed control, container crops, substrates.Species used in this study: flexuous bittercress (Cardamine flexuosa With.), creeping woodsorrel (Oxalis corniculata L.).Chemicals used in this study: pendimethalin (Pendulum 2G), prodiamine + isoxaben (Gemini G), pendimethalin + oxyfluorfen (OH2), and flumioxazin (BroadStar).
Japanese Stiltgrass (Microstegium vimineum) Germination Pattern and its Impact on Control Strategies1
Authors: Payne Geoffrey , Evans Jim , Derr Jeffrey , Murdock Ethan 
Published: August 2020

Abstract
Field trials were conducted by Virginia Master Naturalists to determine the germination period for Japanese stiltgrass and its impact on timing of postemergence herbicide applications. Germination rates declined from April to June, with no germination seen after mid-June. Glyphosate applications in early May significantly reduced Japanese stiltgrass cover that month, but post-treatment germination resulted in approximately 25% cover by October, with 78% cover seen in untreated plots. However, no Japanese stiltgrass was observed in October when glyphosate was applied in either the third week of June or the third week of July. A single application of glyphosate was effective for Japanese stiltgrass control if applications are made in June after new germination had ceased, verified by multi-year herbicide field trials. Field trials conducted by Virginia Tech showed preemergence applications of prodiamine reduced Japanese stiltgrass stand from 30 to 94%, depending on rate and timing, but even in the most effective treatment there was still at least 19% cover by August. Prodiamine treatments that utilized May applications were more effective for crabgrass (Digitaria spp.) control than for Japanese stiltgrass, supporting the earlier germination pattern for Japanese stiltgrass. Inclusion of this work in this paper provides a more complete picture of the treatment options for Japanese stiltgrass. A timed postemergence herbicide application may be a better control option for this weed than use of a preemergence herbicide application.
Index words: herbicide application, invasive plants, weed control.
Chemicals used in this study: Glyphosate [N-(phosphonomethyl)glycine)], prodiamine (2,6-Dinitro-N,N-dipropyl-4-(trifluoromethyl)-1,3-benzenediamine).
Species used in this study: Japanese stiltgrass (Microstegium vimineum (Trin.) A Camus.).
Tolerance of Selected Bluegrass and Fescue Taxa to Simulated Human Foot Traffic
Authors: Evans G. E. 
Published: August 2020

Cultivars of Poa pratensis L., Festuca rubra L., subsp rubra, and Festuca arundinaceae Schreb. were subjected to simulated foot traffic and three irrigation regimes. Soil compaction was evaluated by soil bulk density measurements.
Clipping yields of 16 bluegrass species and cultivars increased with increasing soil moisture. Highest yielding bluegrass cultivars were those with either upright growth habit or rapid vertical growth. The conclusion is drawn that, unless evaluated upon the percent yield change, clipping weights are not an accurate method of assessing trampling resistance of certain strongly rhizomatous, prostrate growing cultivars of Kentucky bluegrass during moderate, continuous trampling. Under the experimental conditions of this study, Poa pratensis L cultivars ‘Merion’, ‘Newport’, and ‘Windsor’ appeared to have greatest resistance to trampling; Poa ampla and Poa trivialis L. having least trample resistance.
Clipping yields of seven cultivars of F. rubra also increased in most cases with increasing irrigation level. Significant yield differences, assumed to represent growth rate differences, occurred among cultivars. Interactions between cultivar and trample level were taken as measures of differential wear tolerance. Festuca rubra L. subsp. rubra ‘Pennlawn’ was significantly higher in trample resistance than all others. F. ovina L. KO-16 had better apparent trample resistance than others which had equal resistance to trampling.
Festuca arundinaceae ‘Goars’ was observed to have superior trample resistance to the others studied which were equal. With a single exception, clipping yields of tall fescue decreased with decrease in irrigation levels.
Effects of Rate and Repeat Application of Flurprimidol on the Growth of Photinia × fraseri and Ilex crenata ‘Compacta’
Authors: Laiche Adolph J. 
Published: August 2020

Flurprimidol, α-(1-Methylethyl)-α-[4-(trifluoromethoxy)phenyl]-5-pyrimidine-methanol, was applied to three month plants of Photinia × fraseri in 5.6 L (6 qt) containers and Ilex crenata ‘Compacta’ in 2.8 L (3 qt) containers as foliar sprays at 0, 33, 66, 132, 264, 528, 1056, 2112, 4224, and 8448 ppnl. Growth-medium drench applications with flurprimidol were applied at 0, 2, 4, 8, 16, 32, 64, 128, 256, and 512 ppm solution, 0.5 L (17 oz) per 5.6 L (6 qt) container to Photinia. The initial foliar spray treatments and the growth medium drench treatments were applied on July 14, 1983. All test plants were planted in soil on December 9, 1983. Foliar spray treatments were repeated on July 19, 1985.
Flurprimidol at low concentrations as a spray and drench substantially reduced plant size with little or no phytotoxicity. Duration of growth suppression increased as rate increased. Flurprimidol at low rates reduced growth for the remainder of the growing season in which it was applied. At higher rates growth was also reduced in the following growing season. Minor leaf distortion of smaller leaves was obtained at low rates and leaf distortion appeared to increase slightly at higher rates. Shoot growth after the effects of flurprimidol were no longer apparent appeared normal. Results indicate that flurprimidol alone and in conjunction with pruning can be helpful in maintaining woody landscape plants to a desirable size.
Preemergent Weed Control in Container-grown Herbaceous Perennials
Authors: Schuett Julie , Klett James E. 
Published: August 2020

Abstract
This study was conducted to evaluate several preemergence herbicides for weed control, effects on plant growth, and phytotoxicity to container-grown herbaceous perennials. Surflan (Oryzalin) was applied at 0, 2.24, 4.48, 6.72 kg ai/ha (0, 2, 4, 6 lb ai/A), Ronstar (Oxadiazon) at 0, 4.48, 8.96, 13.44 kg ai/ha (0, 4, 8, 12 lb ai/A), and Rout (Oxyfluorfen + Oryzalin) at 0, 3.36, 6.72, 10.08 kg ai/ha (0, 3, 6,9 lb ai/A) to container-grown Ajuga reptans atropurpurea L. (carpet bugle), Campanula garganica major (Ten.) Fiori (bellflower), and Liatris spicata (L.) Willd. (spike gayfeather). Additionally, Devrinol (Napropamide) and Treflan (Trifluralin) were each applied at 0, 4.48, 8.96, 13.44 kg ai/ha (0, 4, 8, 12 lb ai/A) to Astilbe × arendsii Arends. (false spirea) and Dicentra spectabilis (L.) Lem. (bleeding heart). Plants were grown in 2.54 1 (#1) containers in a medium of sand, topsoil, and sphagnum peat (1:1:1 by vol). Weed control was acceptable with all herbicides except Surflan at 2.24 kg ai/ha (2 lb ai/A) which did not control shepardspurse. Surflan applied at either 4.48 (41b ai/A) or 6.72 kg ai/ha (61b ai/A) rate resulted in phytotoxicity of carpet bugle, while the 6.72 kg ai/ha rate (6 lb ai/A) significantly reduced plant growth.
Response of Codiaeum variegatum ‘Gold Star’ as Influenced by Slow-Release Fertilizer
Authors: Chase A.R. , Poole R.T. 
Published: August 2020

Abstract
Codiaeum variegatum ‘Gold Star’ croton were grown at different nutritional levels of 3.3, 6.6, 9.9, 13.2, 16.5 and 19.8 g of slow-release 19N-3P-10K (19-6-12) per 12.5 cm (5 in) pot. Plant grade was highest with levels of 3.3–9.9 g per pot, with corresponding leachate electrical conductivity of approximately 200–1100 μmhos·cm−1.
Effect of Fertilizer Level on Severity of Xanthomonas Leaf Spot of Pilea spruceana
Authors: Chase A.R. 
Published: August 2020

Abstract
Severity of Xanthomonas leaf spot of Pilea spruceana was highest for plants receiving intermediate fertilizer rates (recommended to 5 times the recommended rate) and decreased at rates of 6–9 times recommended rate. Plant growth responded similarly with highest quality plants most susceptible to Xanthomonas campestris. Tissue nutrient content for highest quality plants was as follows: N (2.2%), P (0.37–0.38%), K (1.2–1.4%), S (1.00–1.06%), Mg (1.03–1.24%), Ca (2.07–2.30%), Fe (62–76 mg/kg), Mn (358–370 mg/kg), B (50–55 mg/kg), Cu (10 mg/kg), and Zn (348–357 mg/kg). Leachate electrical conductivity for highest quality plants was approximately 200 μmhos/cm. The results indicate that optimizing the nutrient status for highest quality foliar growth of P. spruceana may result in conditions which maximize severity of Xanthomonas leaf spot.
Fertilization of Four Indoor Foliage Plants With Osmocote or Nutricote
Authors: Poole Richard T. , Conover C.A. 
Published: August 2020

Abstract
Aphelandra, Dieffenbachia, Pilea and Chamaedorea grew equally in containers when fertilized with Osmocote or Nutricote incorporated or surface applied. There was slight indication that plants grew better at higher than recommended rate, but increased fertilizer costs and potential for ground water contamination suggest higher rates should not be used.
Propagation of Quercus L. Species by Cuttings
Authors: Drew John J. , Dirr Michael A. 
Published: August 2020

Abstract
Ten species of oak, Quercus L., were used to determine the feasibility of rooting oak cuttings. Cuttings were taken from the first, second, and third growth flushes from seedling stock plants (2 to 3-year-old) and treated with 1.0% potassium 1H-indole-3-butanoic acid (K-IBA), 5-sec. dip and placed under mist. Rooting ranged from 0% to 80% with Q. phellos L., Q. robur L., and Q. lyrata Walter rooting 80%,69%, and 43%, respectively, on the first date. Generally, rooting decreased with progressive flushes. Quercus alba L. and Q. suber L. rooted 2% or less over all dates. No consistent pattern of rooting was observed for white oak compared to red oak groups. Rooting was strongly species specific.
Damage Caused by Wind-Borne Salts to Landscape Plants and its Prevention by a Wind-Controlled Sprinkler System
Authors: Hagiladi A. , Ben-Jaacov J. , Eliasaf A. 
Published: August 2020

Abstract
Ocean spray carried by wind was shown to be the main cause of leaf scorching of vegetation along the Mediterranean coast of Israel. An overhead sprinkling system was designed to be activated when wind velocity reached a critical level. It was shown to reduce leaf scorching. The degree of protection depended on plant species. Plants showed different degrees of sensitivity to wind-borne salts in the following increasing order: Japanese Pittosporum (Pittosporum tubira Ait.), Thorny Elaeagnus (Elaeagnus pungens Thunb.), Common Oleander (Nerium oleander L.), Tamarisk, Athel (Tamarix aphylla Karst.).
Lowering of Calcareous Soil pH in Field-Grow Containers
Authors: Kidder G. , Holsinger M.J. , Yeager T.H. 
Published: August 2020

Abstract
Wettable sulfur (S) mixed with a Pineda fine sand (an Arenic Glossaqualf with 7.8 pH and 1.5% calcium carbonate equivalent) quickly acidified the soil, but the effect was lost within 8 weeks at low application rates and within 21 weeks at the highest rate (1 g S/kg soil or 1 lb S/1000 lb soil). Granular S mixed with the soil took one year to produce maximum pH reduction of 0.3, 0.4, and 0.9 pH units at 250, 500, and 1000 mg S/kg soil (1/4, 1/2, and 1 lb S/1000 lb soil), respectively . Wettable sulfur (S), surface-applied at 100 g/m2 (0.036 oz/10 ft2), lowered the pH of the upper 5 cm (2 in) of soil to the 5.6 to 5.8 range for one to two months before the pH returned to &gt; 7.0; granular S took about five months to lower the pH to 6.7 but the soil pH was 6.2 two years after application. Wettable S at 20 g/kg soil (0.32 oz S/lb soil) in a small cylindrical zone resulted in a temporary depression of pH within the treated zone but had no effect on pH in other areas of the container. Mixing up to 1.0 g iron sulfate/kg soil (0.016 oz/lb soil) failed to reduce soil pH. Live-oak trunk diameter and plant height were not affected by any of the soil treatments in the two-year experiment.
Desiccation Tolerance of Deciduous Plants During Postharvest Handling
Authors: Murakami Paul , Chen Tony H.H. , Fuchigami Leslie H. 
Published: August 2020

Abstract
Nurserymen consider Washington hawthorn (Crategus phaenopyrum Med.) sensitive and Norway maple (Acer platanoides L.) tolerant to postharvest practices. The desiccation tolerance, cold hardiness and water potential at various growth stages were monitored on field-grown Washington hawthorn and Norway maple. There were no differences between these two species in the rate of water loss in the root, shoot or whole plants. Hawthorn, however, was more sensitive to desiccation stress than maple throughout all growth stages. The roots lost water at a faster rate than the stems in both species. Hawthorn plants acquired rest and cold hardened later in the fall and attained less dormancy and less freezing tolerance than did maple.
Insecticidal Bark Bands for Reduction of Defoliation by Elm Leaf Beetle (Coleoptera: Chrysomelidae)
Authors: Hall R.W , Nielsen D.G. , Young C.E. , Hamerski M.R. 
Published: August 2020

Abstract
An experiment was conducted to evaluate the effectiveness of carbaryl (Sevin XLR +) applied to elm bark for prevention of defoliation by elm leaf beetle, Xanthogaleruca luteola (Müller). Trunks of trees were treated with 2% carbaryl applied as a 1 m (3.3 ft) wide band. First generation larvae were killed when descending treated trees as they moved toward pupation sites. Insecticide bands were generally effective in preventing defoliation at treated sites. However, defoliation by first generation larvae at one treated site caused unacceptable aesthetic damage.
Variation among Picea pungens Progenies grown in Ohio
Authors: Townsend A.M , Douglas L.W. 
Published: August 2020

Abstract
Wide variation in foliage color, height, and form was found among progenies of blue spruce (Picea pungens Engelm.) grown in Ohio from seed collected from 32 provenances. Data were collected seven and 12 years after permanent field planting of 3-3 stock. Broad differences also occurred among 4 geographic regions, each made up of anywhere from 4 to 12 provenances. Trees from the region (Region 3) of southern Colorado, northern New Mexico, and northern Arizona averaged the fastest growth, bluest color, and most symmetrical form. Those trees from Utah and Wyoming (Region 2) most often had the slowest growth rate and least desirable form and color. The average performance of trees from northern Colorado (Region 1) and southern New Mexico and southern Arizona (Region 4) was generally intermediate between that of Region 2 and Region 3. Although regional differences were significant, great variability existed among provenances across the entire range of the species. Nurserymen desiring to grow blue spruce with improved growth rate, color, and form at a lower cost should consider collecting seed from those seed sources which have consistently proven themselves to be superior in this and other studies.
Minimizing Disease Injury To Hybrid Poplars
Authors: Ostry Michael E. , McNabb Harold S. 
Published: August 2020

Abstract
Poplars (Populus L.) are among the most versatile of trees, but many poplar hybrids have often failed to grow as advertised because of their high susceptibility to several diseases. Chemical and cultural controls have been developed that can minimize disease incidence in hybird poplars, but planting resistant clones is believed to be the best long-term management strategy. Nursery operators need to produce these disease resistant clones in order to increase market acceptability.
Water Absorption of Hydrophylic Polymers (Hydrogels) Reduced by Media Amendments
Authors: Foster William J. , Keever Gary J. 
Published: August 2020

Abstract
Water absorbency of 4 commercially available hydrophylic polymers (hydrogels) (Agrosoke, Liqua-gel, Mizuace and Terra-sorb HB) in response to 4 media amendments (Micromax, Osmocote 18N-2.6P-10.0K (18-6-12), gypsum and dolomitic limestone) and the combination of 4 amendments was determined. Water absorbency of 4 hydrogels was reduced by all amendments except Osmocote added to Liqua-gel. Generally, hydrogel absorbency was reduced most by Micromax and the combination of media amendments, followed by gypsum, Osmocote, and dolomitic limestone. None of the hydrogels functioned as advertised.
Growth Response of 13 Container-Grown Landscape Plants to Uniconazole
Authors: Warren Stuart L. 
Published: August 2020

Abstract
Uniconazole, an experimental plant growth regulator, was applied as a foliar spray and a medium drench to 13 and 7 species, resp. Shoot dry weight was determined at 60, 90, and 120 days after treatment. Sixty days after treatment, shoot dry weight of no species was affected by uniconazole. At 90 and 120 days, shoot dry weight of all species, except golden privet (Ligustrum × vicaryi), Russian-olive (Elaeagnus angustifolia), and waxleaf privet (Ligustrum lucidum), decreased with increasing rates of uniconazole, regardless of method of application. Degree of growth reduction varied by species, rate, and method of application. For most species, uniconazole was effective in suppressing growth for 120 days. Generally greater reduction of shoot growth resulted from drench application compared to foliar application.
Paulownia tomentosa Seedling Growth at Differing Levels of pH, Nitrogen, and Phosphorus
Authors: Melhuish J. H. , Gentry C. E. , Beckjord P. R. 
Published: August 2020

Abstract
This study examined the effects of various levels of acidity, nitrogen, and phosphorus on the survival and growth of Paulownia tomentosa seedlings. The seedlings grew within a pH range of 7.0 to 4.0, but little or no growth occurred at pH 3.0. The seedlings grew well with nitrogen at 50 to 200 ppm and phosphorus at 5 ppm, but growth was greatly reduced below 10 ppm nitrogen. Higher levels of phosphorus need to be investigated.
Influence of Spectral Filters on Height, Leaf Chlorophyll, and Flowering of Rosa × hybrida ‘Meirutral’
Authors: McMahon M.J. , Kelly J.W. 
Published: August 2020

Abstract
Growth of Rosa × hybrida ‘Meirutral’ under different spectral filters was evaluated. Two filters that altered far-red (730 nm)/red (660 nm) light (FR/R) were developed. One, a blue textile dye, increased FR/R by filtering out a portion of red light. The second, a salt (copper sulfate) decreased FR/R by filtering out a greater portion of far-red than red light. A third filter that did not alter light quality was the control. The filters were installed in specially built growth chambers. Photosynthetic photon flux (PPF) was adjusted to equal values in each chamber.
Plants were significantly shorter and had higher leaf chlorophyll when grown under the reduced FR/R filter. The number of flower buds and number of buds showing color at termination of the experiment was not affected by light quality treatments.
Tree Root Growth and Development. I. Form, Spread, Depth and Periodicity
Authors: Gilman Edward F. 
Published: August 2020

Abstract
Root form is governed by seedling genetics and soil characteristics including texture, compaction, depth to the water table, fertility, moisture content and other factors. Trees develop lateral roots growing parallel to the surface of the soil. These are generally located in the top 30 cm (12 in) of soil. Fine roots emerge from lateral roots and grow into the soil close to the surface. If soil conditions permit, some trees grow tap and other vertically oriented roots capable of penetrating several feet into the soil. Many trees, particularly those planted in urban landscapes, do not generate tap roots. Lateral roots spread to well beyond the edge of the branches. Their growth in governed by competition from other plants, available water, soil temperature, fertility, stage of shoot growth and other factors.
Evaluation of Thermal Properties and Effect of Irrigation on Temperature Dynamics in Container Media
Authors: Martin Chris A. , Ingram Dewayne L. 
Published: August 2020

Abstract
Thermal energy flows in pine bark, 4 pine bark: 1 sand (by vol), and 3 pine bark: 2 sand (by vol) media as a function of volumetric water content were studied. The predicted rate of movement of heat energy was greatest for the 3 pine bark: 2 sand medium if the volumetric water content was between 10% and 65%. Field experiments were conducted to evaluate the effects of irrigation volume and timing and container media composition on container media temperature dynamics using a spray stake delivery system. Irrigating 10-liter (#3) containers with water at 26°C (79°F) was most effective as a container medium coolant if the volume which was applied equaled or exceeded 3.0 liters (0.8 gal), the applications were made beginning at midday, and sand was in the container medium compared to pine bark alone.
Tolerance of Woody Nursery Stock to Classic (chlorimuron) and Harmony (thiameturon)
Authors: Derr Jeffrey F. 
Published: August 2020

Abstract
Classic and Harmony applied at rates ranging from 0.009 kg ai/ha (0.008 lb ai/A) to 0.067 kg/ha (0.06 lb/A) provided excellent preemergence and postemergence control of common groundsel (Senecio vulgaris L.) 5 weeks after application to container-grown nursery plants. Classic at 0.034 kg/ha (0.03 lb/A) and 0.067 kg/ha (0.06 lb/A) reduced yellow nutsedge (Cyperus esculentus L.) growth by 50 to 77% 5 weeks after preemergence or postemergence treatments. Harmony did not affect yellow nutsedge from either type of application. ‘Seagreen’ juniper (Juniperus chinensis L.), ‘Blue Pacific’ juniper (Juniperus conferta Parl.) and ‘Bennetts Compacta’ holly (Ilex crenata Thunb.) tolerated all rates of Classic and Harmony. ‘Girard's Rose’ (Rhododendron kaempferi Planch.) and ‘Coral Bells’ azale(Rhododendron obtusum (Lindl.) Planch.), and redtip photinia (Photinia × Fraseri Dress) were initially injured by these herbicides, but outgrew the foliar damage.