bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining the Microwave Radiations Exposure Level Needed for Weed Control Using a Stationary and Running Belt Microwave Radiations Applicator System1
Authors: Rana Aman , Derr Jeffrey F. 
Published: August 2020

Abstract
There is a demand for nonchemical weed control strategies, with microwave radiations one possible option. Accurately measuring a weed's exposure level to microwave radiations is a challenge when there is a gap between when electricity is applied to the magnetron and actual production of microwave radiations. This gap causes an error in the calculation of actual energy needed for weed management. Any misinterpretation over-estimates the required energy load, adversely affecting the perceived value of the technology. Studies were conducted to eliminate the existing lag period. A running belt prototype was built for this purpose using two magnetrons producing 900 watt each installed on a treadmill with a power supply. There was significant improvement in the precision for calculations of total energy required for weed control. These anatomically diverse weeds showed more uniform thermal injuries and greater control using the running belt prototype system than a stationary unit. The LD50 for broadleaf weeds treated with microwave radiations using the running belt system ranged from 31.2 joules.cm−2 for common ragweed (Ambrosia artemisiifolia L.) to 36.8 joules.cm−2 for pitted morningglory (Ipomoea lacunosa L.). In comparison, treatment of weeds with microwave radiations using the stationary mode system resulted in a range of LD50 values of 64.5 joules.cm−2 for common ragweed to 155.1 joules.cm−2 for white clover (Trifolium repens L.). Similarly, the LD50 values for grasses treated with microwave radiations using the running belt system ranged from 34.3 for dallisgrass (Paspalum dilatatum Poir.) to 69.5 joules.cm−2 for southern crabgrass [Digitaria ciliaris (Retz.) Koeler]); in comparison, the range in LD50 values for grasses treated with stationary system was 136.1 to 182 joules.cm−2. The LD50 values for sedges treated with microwave radiations using the running belt system ranged from 29.2 joules.cm−2 for yellow nutsedge (Cyperus esculentus L.) to 78.1 joules.cm−2 for fragrant flatsedge (Cyperus odoratus L.); in comparison, the range in LD50 values for the stationary mode system was 119.4 joules.cm−2 for fragrant flatsedge to 145.9 joules.cm−2 for yellow nutsedge.
Index words: Nonchemical control, weed control, efficacy, prototype, weed management.
Effects of Tree Production Method and Transplanting on Root Hydraulic Conductance1
Authors: Yin Jingjing , Harper Richard W. , Bassuk Nina L. 
Published: August 2020

AbstractThe objective of this study was to investigate the post-transplant, root specific hydraulic conductance (KS) of two oak species (Quercus bicolor Willd. and Quercus rubra L.). Q. bicolor and Q. rubra trees responded differently to transplanting across the differing types of production methods. Overall, higher post-transplant fine root KS resulted in a larger leaf area after transplanting. Container-grown (CG) trees had the highest root KS immediately after transplanting compared to balled-and-burlapped (BNB), in-ground fabric (IGF), and bare-root (BR) trees, but KS in CG trees was largely reduced at the end of the first growing season after transplanting. Post-transplant variations of fine root KS also differed between the two tree species. Fine root KS remained similar in BNB and IGF Q. bicolor trees after transplanting, but increased with time after transplanting in Q. rubra trees. The increase in KS was especially greater in BNB and BR Q. rubra trees than IGF Q. rubra.Index words: transplanting, root hydraulic conductance, tree production method, Quercus bicolor, Quercus rubra, oak.Species used in this study: Swamp white oak (Quercus bicolor Willd.); northern red oak (Quercus rubra L.).
Dimethenamid Persistence and Leaching Potential in a Soilless Mix1
Authors: Robertson Lori , Derr Jeffrey F. 
Published: August 2020

Abstract
Dimethenamid and the granular combination product pendimethalin plus dimethenamid are herbicides registered for use in nursery production and landscape maintenance. The objectives of this study were: (1) to compare the effectiveness of sprayed dimethenamid and the granular combination of pendimethalin plus dimethenamid in container nursery production, (2) to determine the impact of formulation on leaching of dimethenamid in soilless media versus field soil and (3) to determine the influence of irrigation volume on herbicide leaching. Dimethenamid is less mobile in pine bark than field soil, while pendimethalin is more mobile in pine bark. The leaching profile for the granular pendimethalin plus dimethenamid combination product was similar to dimethenamid in field soil and similar to pendimethalin in pine bark. There was no significant difference in herbicide movement in pine bark or field soil after doubling the irrigation volume from 17.8 cm (7 in) to 35.6 cm (14 in). Compared to pendimethalin, dimethenamid leaches less in pine bark, explaining its greater effectiveness for weed control in container production.
Index words: Herbicide leaching, soilless mix, pine bark, ornamentals, adsorption.
Species used in this study: southern crabgrass [Digitaria ciliaris (Retz.) Koel.]; spotted spurge [Chamaesyce maculata (L.) Small].
Chemicals used in this study: dimethenamid (Tower); dimethenamid plus pendimethalin (FreeHand); pendimethalin (Pendulum 2G).
Shallow Substrates Support the Growth of Contrasting Plant Types Installed in Irrigated, Arid-Climate Green Roofs1
Authors: Forrest Lauren , Gioannini Rachel , VanLeeuwen Dawn M. , Hilaire Rolston St. 
Published: August 2020

Abstract
Extreme evaporative demand makes substrate depth a critical design factor in arid-climate green roofs. The objective of this study was to determine whether a shallow irrigated substrate could support the growth of hens and chicks (Sempervivum calcareum L.) and iceplant [Delosperma nubigenum (Hook.f.) L.Bolus] in an arid environment. First, an experiment was conducted in the greenhouse that established that plants survived in 10 cm (3.9 in), 15 cm (5.9 in), and 20 cm (7.9 in) substrate depths, which then lead to a second experiment in an outdoor environment. The substrate was heat-expanded clay:sand:worm castings (6:3:1, by volume) in a greenhouse experiment and heat-expanded clay:zeolite:worm castings (6:3:1, by volume) in an outdoor experiment. In the greenhouse experiment, deep root length density (RLD) was significantly greater in the 10 cm-deep (3.9 in) substrate, while outdoors, deep RLD was highest for plants grown in the 15 cm-deep (5.9 in) substrate. Outdoors, iceplant had significantly greater mean coverage and shoot dry weight than hens and chicks. Lack of significant differences in quality and coverage due to substrate depth, coupled with higher RLD in the 10 cm (3.9 in) and 15 cm (5.9 in) depths in both experiments provides evidence that shallow irrigated substrates support the growth of both taxa.
Index words: iceplant, hens and chicks, plant coverage, root length density, quality, zeolite, heat expanded clay.
Species used in this study: hens and chicks (Sempervivum calcareum L.); iceplant [Delosperma nubigenum (Hook.f.) L. Bolus].
Long-term Weed Control for Landscape Pecan (Carya illinoinensis) Trees1
Authors: Hand Lavesta C. , Foshee Wheeler G. , Monday Tyler A. , Sibley Jeff L. 
Published: August 2020

Abstract
Studies were conducted at the E.V. Smith Research Center in Shorter, AL (32°43′N, -85°89′W) in 2013 and 2014 to evaluate herbicides suitable for providing season-long weed control in pecan orchards. Herbicide treatments included: (1) glyphosate applied at 1.12 kg ae·ha−1 (1.0 lb ae·A−1), (2) glyphosate at 1.12 kg ae·ha−1 + indaziflam at 73.1 g ai·ha−1 (1.04 oz ai·A−1), (3) glyphosate at 1.12 kg ae·ha−1 + flumioxazin at 422 g ai·ha−1 (6.02 oz ai·A−1) + pendimethalin at 4.25 kg ai·ha−1 (3.79 lb ai·A−1), and (4) a nontreated control. Glyphosate + indaziflam provided the highest weed-free area at all rating dates, but at 150 DAT (69%) it wasn't acceptable. Glyphosate + flumioxazin + pendimethalin provided a similar weed-free area to glyphosate + indaziflam 30 DAT (88%).
Index words: landscape weed control, shade trees, pecan, edible landscape.
Species used in this study: Carya illinoinensis (Wang.) K. Koch ‘Desirable'.
Chemicals used in this study: indaziflam (Alion®), glyphosate (Cornerstone Plus), flumioxazin (Chateau ®), pendimethalin (Prowl H20®).
Increasing amounts of coir dust in substrates do not improve physical properties or growth of tree seedlings in a novel air-pruning propagation tray1
Authors: Munroe Ryan , McGrath Darby , Henry Jason 
Published: August 2020

AbstractAir-pruning can improve tree seedling root quality in propagation by subjecting root tips to desiccation, thereby avoiding deflections, but also increases substrate dry-out rates. Several studies have indicated that coconut (Cocos nucifera L.) coir dust can enhance water holding properties, possibly benefiting trees grown in air-pruning trays. However, water availability characteristics are influenced by particle size. In this experiment, coir dust was added into a sphagnum peat-perlite substrate mix at rates of 10, 15 and 20%. An industry standard peat-perlite mix was tested as a fourth substrate type. Red oak (Quercus rubra L.), red maple (Acer rubrum L.), quaking aspen (Populus tremuloides Michx.) and eastern white cedar (Thuja occidentalis L.) were grown from seed in these four substrate types. Physical and chemical properties of all substrate types were analyzed pre-experiment. The particle size distribution was finer and more even in the peat-perlite mix compared to the three coir mixes. The higher proportion of coarse particles in the 20% coir mix may have reduced water availability. Seedlings grown in the 15 and 20% coir mixes had lower above and below-ground growth compared to the 10% coir and peat-perlite mixes in all species except red oak.Index words: soilless media, water holding capacity, air space, particle size distribution, chlorophyll content, tree growth.Species used in the study: red oak (Quercus rubra L.); red maple (Acer rubrum L.); quaking aspen (Populus tremuloides Michx.); eastern white cedar (Thuja occidentalis L.).
Insights from Southeastern US Nursery Growers Guide Research for Sterile Ornamental Cultivars 1
Authors: Bechtloff Allison , Adams Dr. Carrie Reinhardt , Wilson Dr. Sandra , Deng Dr. Zhanao , Wiese Christine 
Published: August 2020

Abstract
Some ornamental plants important to the nursery and landscape industries escape cultivation, spread to natural areas, and become invasive, outcompeting native plants in those ecosystems. Development of sterile cultivars of these problematic species can be one way to continue their sales yet limit their invasive potential and protect natural areas. To maximize the economic (and ecological) impact of this approach, sterile cultivar research and development should directly address grower needs. We conducted a survey of southeastern US growers to quantify sales of five popular yet invasive ornamentals (Coral ardisia, Chinese privet, Japanese honeysuckle, Heavenly bamboo, and Mexican petunia). Firms ranged from small businesses to large operations with up to $30M in gross annual sales. Respondents expressed a largely positive opinion of sterile cultivar research (74%) and a willingness to sell the sterile cultivars once created. Most (40%) recommended that sterile cultivar research on Heavenly bamboo was most critical, while 30% suggested that Chinese privet was the most important research target of the five species. The industry's willingness to adopt sterile cultivars documented in this survey positions the southeastern US to lead development of sterile cultivars and reduce invasiveness of economically important plants; research and development will be most effective if guided by industry input revealed here.
Index words: Invasive species, invasive ornamental, sterile cultivar, ornamental plants, non-invasive, non-native, survey, nursery production, economic impacts.
Species used in this study: Coral ardisia (Ardisia crenata Sims); Chinese privet (Ligustrum sinense Lour.); Japanese honeysuckle (Lonicera japonica Thunb.); Heavenly bamboo (Nandina domestica Thunb.); Mexican petunia (Ruellia simplex C.Wright).
Optimizing Temperature and Humidity for Rooting Hybrid Hazelnuts from Hardwood Stem Cuttings1
Authors: Braun Lois , Wyse Donald 
Published: August 2020

Abstract
Hybrid hazelnuts are being developed as a new crop for the Upper Midwest for their ecological and economic value, but lack of economically viable propagation methods is a significant bottleneck to their wide scale adoption. In previous trials we found that hardwood stem cuttings could be propagated in low cost humidity tents constructed of molded plastic tubs covered with white 70% shade plastic. When the plastic was sealed tightly at the sides, these tubs maintained relative humidity near saturation, but also tended to overheat. This trial experimented with the use of ordinary household humidifiers as an alternative way of maintaining humidity while avoiding overheating. We found that it is not necessary to maintain RH near 100% as we had been doing when we kept the humidity tents tightly sealed. Stem survival and, as a consequence, rooting were improved in vented tents in which humidity was maintained with humidifiers, though these required much more management than the sealed tents.
Index words: Propagation, Corylus americana (Walter), Corylus avellana (L.), rooting, indole-3-butyric acid
Chemicals used in this study: indole-3-butyric acid (IBA)
Species used in this study: hybrid hazelnuts [Corylus americana (Walter) x Corylus avellana (L.)]
Effects of Fertilizer Placement on Greenhouse Gas Emissions from a Sun and Shade Grown Ornamental Crop1
Authors: Murphy Anna-Marie , Runion G. Brett , Prior Stephen A. , Torbert H. Allen , Sibley Jeff L. , Fain Glenn B. , Pickens Jeremy M. 
Published: August 2020

Abstract
The level to which ornamental plant production impacts rising atmospheric greenhouse gas (GHG) concentrations remains unknown. Research to date has focused on developing baseline estimations of GHG emissions from plant-pot production systems and their contribution to global warming potential. To date, pot size, irrigation delivery method and fertilizer application method have been evaluated in the production of common woody ornamental crops. In this study, two perennial herbaceous plants, full-sun-grown ‘Stella D'Oro' daylily (Hemerocallis × ‘Stella D'Oro' L.) and shade-grown ‘Royal Standard' hosta (Hosta × ‘Royal Standard') (Hosta plantaginea Aschers × Hosta sieboldiana N.Fujita) were grown utilizing one of three common fertilizer application methods (dibbled, incorporated or top-dressed). Plants were grown in 3.8 L (1 gal) nursery containers in a 6:1 pinebark:sand substrate with standard amendments. Gas samples were collected in situ according to standard GRACEnet protocols weekly for five months. Cumulative emissions for both CO2 and N2O were least for plant-pot systems using the dibbled fertilizer method, regardless of species. Cumulative CO2 emissions were highest for plants fertilized by incorporation, followed by those fertilized by top-dressing. No differences were observed between N2O efflux measurements for systems fertilized by either the incorporated or top-dressed methods. Results suggest that dibbling fertilizer could significantly decrease both CO2 and N2O emission.
Index words: carbon dioxide, nitrous oxide, methane, trace gas.
Species used in this study: ‘Stella D'Oro' daylily (Hemerocallis × ‘Stella D'Oro' L.); ‘Royal Standard' hosta [(Hosta × ‘Royal Standard') (Hosta plantaginea Aschers × Hosta sieboldiana N.Fujita)].
Research Priorities of the Environmental Horticultural Industry Founded through Consensus1
Authors: Owen James S. , LeBude Anthony V. , Calabro Jill , Boldt Jennifer K. , Gray Jennifer , Altland James E. 
Published: August 2020

Abstract
Environmental horticulture production (EHP) generates and employs approximately one-third of all specialty crop revenue and workforce, respectively. In recent years, however, EHP received only 12% of federal funds earmarked for specialty crops research from the USDA-Agricultural Research Service or the USDA-Specialty Crops Research Initiative. To increase leverage and accumulate more resources for EHP, stakeholder-driven consensus of research priorities needed to be constructed. Therefore, the Horticultural Research Institute led a professionally facilitated stakeholder roundtable discussion to achieve these priorities. Stakeholders identified trends and forces affecting EHP, its current state, a vision, and outcomes needed for success. Through consensus, four equal research priorities were constructed: 1) quantitate and validate the ecosystem services and benefits of plants on human health and wellness, 2) develop innovations in biological, mechanical, and technological systems that provide efficient, productive, and profitable solutions relevant to producer size and segment, 3) evaluate consumer-driven preferences that optimize industry-wide profitability and growth, and 4) solve ongoing and emergent industry challenges. These priorities and the successful future of EHP will be made possible by strong leaders and advocates positioned throughout industry, successfully communicating the human health, social, and economic benefits of plants, state-of-the-art technological and efficiently-designed systems, and an understanding of current and future consumers.
Index words: forces, greenhouse, innovation, nursery, roadmap, stakeholders, trends, vision.
Implementation of Soil Moisture Sensor Based Automated Irrigation in Woody Ornamental Production1
Authors: Wheeler William D. , Chappell Matthew , van Iersel Marc , Thomas Paul 
Published: August 2020

Abstract
A soil moisture sensor-based automated irrigation system was trialed in a commercial ornamental nursery over the 2014-2015 growing seasons. In both years, use of the sensor-based system resulted in an approximate 50% reduction in irrigation application (volume) when compared to grower-managed irrigation. No differences in growth and equivalent or slightly reduced crop losses were noted when comparing the sensor-based irrigation system to grower-managed irrigation in production of Pieris japonica, Hydrangea quercifolia, and Kalmia latifolia. In 2014, Rhododendron catawbiense had equivalent canopy size and reduced mortality when comparing sensor-based irrigation to grower-managed irrigation. However, in 2015 irrigation control with the sensor-based system resulted in significant (&gt;50%) Rhododendron losses. High mortality was thought to have resulted from use of averaged (across crop species) soil moisture readings to establish irrigation set points. Canopy structure of Rhododendron obstructed water capture to a greater degree than the other three species due to canopy architecture. This effect, combined with precision irrigation applications, resulted in persistent drought conditions within the Rhododendron block. Soil moisture sensor-based automated irrigation can be an effective means of automating irrigation. Support from crop consultants is highly desirable to minimize disruption and maximize adoption during implementation.
Index words: Pieris Japonica D. Don ex G. Don ‘Prelude', Hydrangea quercifolia W. Bartram ‘Jet Stream', Rhododendron catawbiense Michx. ‘Roseum Elegans', Kalmia latifolia L. ‘Sarah', irrigation groupings, automation, canopy structure, irrigation capture, technology transfer, outreach, education, precision irrigation
Species used in this study: Japanese andromeda ‘Prelude' (Pieris Japonica D. Don ex G. Don); Oakleaf hydrangea ‘Jet Stream' (Hydrangea quercifolia W. Bartram); Rhododendron ‘Roseum Elegans' (Rhododendron catawbiense Michx.); Mountain laurel ‘Sarah' (Kalmia latifolia L.)
Physiological Response to Water Deficit Stress with Restricted Rooting in Tall Fescue and Zoysiagrass
Authors: Culpepper Travis , Young Joseph , Montague David T. , Sapkota Manish , Escamilla Eduardo , Wherley Benjamin 
Published: August 2020

AbstractUrban soils may restrict turfgrass rooting depth with shallow soil layers in high sand content soils, which may influence water conservation. A greenhouse study sought to quantify water usage and determine the physiological response of turfgrasses at four irrigation levels. ‘ATF-1434′ tall fescue (Schedonorus arundinaceus (Schreb.) Dumort. nom. cons.; syn. Festuca arundinacea Schreb.), ‘Jamur' Japanese lawngrass (Zoysia japonica Steud.), and ‘Zeon' Manilagrass [Zoysia matrella (L.) Merr.] were established in 10 cm (4 in) diameter by 17.8 cm (7 in) tall containers. Each species was irrigated with 16.5, 21.9, 27.3, or 32.7 mm.wk−1 (0.65, 0.86, 1.1, or 1.3 in.wk−1). Gravimetric water loss was determined by pre- and post-irrigation pot weights. Turf quality, leaf discoloration, percent green cover, and gross photosynthesis were evaluated weekly and root parameters were measured at the conclusion of each trial. Although root mass was similar among species, water deficit stress and leaf discoloration occurred sooner in tall fescue than the two Zoysia species, reducing turf quality and green cover. Japanese lawngrass and Manilagrass had greater stomatal conductance, resulting in 109 and 89% higher gross photosynthesis relative to tall fescue. Both zoysiagrasses maintained acceptable turf quality with 27.3 mm water.wk−1. However, tall fescue quality was not acceptable at any irrigation level.Index words: Photosynthesis, gravimetric water loss, tall fescue, Japanese lawngrass, Manilagrass.Species used in this study: Tall fescue (Schedonorus arundinaceus (Schreb.) Dumort. nom. cons.; syn. Festuca arundinacea Schreb.); Japanese lawngrass (Zoysia japonica Steud.); Manilagrass [Zoysia matrella (L.) Merr.].
Water Savings and Return on Investment of a New Drought Resistant Turfgrass
Authors: Minor Josh , Campbell Benjamin , Waltz Clint , Berning Joshua 
Published: August 2020

Abstract
Bermudagrass is a commonly used turfgrass for home lawns and sports fields. Given increasing pressure to conserve water throughout the U.S., there is a desire by many homeowners to incorporate more drought-tolerant turfgrasses into their landscape. ‘TifTuf' is a new cultivar of bermudagrass that has increased drought tolerance compared to similar cultivars. ‘TifTuf' is currently sold at a premium price compared to other bermudagrass cultivars. However, there is currently no information regarding the payback period and potential water savings for ‘TifTuf'. In this study, we developed a model to evaluate potential cost savings for ‘TifTuf' relative to a conventional bermudagrass. We found cost and water savings are highly dependent on geographic location and water rates. Within the Southeast, the average water savings per year is 12.88 cm with water cost savings around $799 per 0.41 ha. Payback period for a new lawn in the Southeast (recoup only the $0.05 per 0.09 m2 premium) is around 3-4 years, while a payback period for a replacement lawn (recoup the full cost of the lawn, $0.36 per 0.09 m2) is around 21 years. In the Southwest, the water savings and cost savings are higher, implying a shorter payback period.
Index words: bermudagrass, ‘TifTuf', drought tolerance.
Species used in this study: Cynodon dactylon x C. transvaalensis: DT-1 ‘TifTuf'.