Browsing by Author "Derr, Jeffrey F."

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    2016 Spray Bulletin for Commercial Tree Fruit Growers
    Pfeiffer, Douglas G.; Bergh, J. Christopher; Frank, Daniel L.; Hooks, C. R. R.; Walsh, C. S.; Yoder, Keith S.; Rahan, Mahfaz; Kotcon, J. B.; Derr, Jeffrey F.; Chandran, Rakesh S.; Weaver, Michael W.; Brown, Amy; Parkhurst, James A. (2016-01-01)
    This is a multi-state guide, with orchard recommendations for Virginia, West Virginia and Maryland.
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    2017 Spray Bulletin for Commercial Tree Fruit Growers. Va. Coop. Ext. Serv. Publ. 456-419
    Pfeiffer, Douglas G.; Bergh, J. Christopher; Wilson, James M.; Frank, Daniel L.; Hooks, C. R. R.; Sherif, Sherif M.; Walsh, C. S.; Yoder, Keith S.; Rahman, M.; Kotcon, J. B.; Derr, Jeffrey F.; Chandran, Rakesh S.; Weaver, Michael J.; Brown, Amy; Parkhurst, James A. (2016)
    Integrated pest management (IPM) is the approach emphasized in this guide; some aspects of IPM are incorporated throughout, although this guide mainly deals with the chemical component of IPM. IPM combines biological control from predators with selective chemical application for maintaining pest populations below economic threshold levels. This approach requires that growers give careful consideration to the selection, application rate and timing of chemical sprays. The degree of integration achieved will vary according to the management ability, training and objectives of the orchardist. Inadequate monitoring or implementation of IPM practices will lead to unsatisfactory results. In order to encourage the biological control components of the program, growers must consider the toxicity of chemicals to predators (Table 9, page 59) in addition to their efficacy against fruit pests (Tables 7 and 8, pages 56-58).
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    2020 Spray Bulletin for Commercial Tree Fruit Growers: Virginia, West Virginia, and University of Maryland
    Pfeiffer, Douglas G.; Bergh, J. Christopher; Wilson, James; Hooks, C. R. R.; Sherif, Sherif M.; Walsh, C. S.; Yoder, Keith S.; Rahman, Mahfaz; Kotcon, J. B.; Derr, Jeffrey F.; Chandran, Rakesh S.; Frank, Daniel L.; Wycoff, Stephanie B.; Brown, Amy; Parkhurst, James A. (2020)
    Integrated pest management (IPM) is the approach emphasized in this guide; some aspects of IPM are incorporated throughout, although this guide mainly deals with the chemical component of IPM. IPM combines biological control from predators with selective chemical application for maintaining pest populations below economic threshold levels. This approach requires that growers give careful consideration to the selection, application rate and timing of chemical sprays. The degree of integration achieved will vary according to the management ability, training and objectives of the orchardist. Inadequate monitoring or implementation of IPM practices will lead to unsatisfactory results. In order to encourage the biological control components of the program, growers must consider the toxicity of chemicals to predators (Table 9, page 59) in addition to their efficacy against fruit pests (Tables 7 and 8, pages 56-58)...
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    2021 Home Grounds and Animals PMG - Author Contact List
    Askew, Shawn D.; Wycoff, Stephanie B.; Bergh, J. Christopher; Bush, Elizabeth A.; Day, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F.; Frank, Daniel L.; Hansen, Mary Ann; Hong, Chuan X.; Laub, Curtis A.; McCall, David S.; Miller, Dini M.; Nita, Mizuho; Parkhurst, James A.; Paulson, Sally L.; Pfeiffer, Douglas G.; Rideout, Steven L.; Wilson, James; Yoder, Keith S. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter of the 2021 Home Grounds and Animals PMG. This 2021 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. This publication contains information about prevention and nonchemical control as alternatives to chemical control or as part of an integrated pest management approach. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.
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    2021 Home Grounds and Animals PMG - Home Ornamentals
    Hong, Chuan X.; Hansen, Mary Ann; Bush, Elizabeth A.; Day, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter of the 2021 Home Grounds and Animals PMG. This 2021 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. This publication contains information about prevention and nonchemical control as alternatives to chemical control or as part of an integrated pest management approach. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.
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    2021 Home Grounds and Animals PMG - Home Vegetables
    Day, Eric R.; Del-Pozo, Alejandro; Bush, Elizabeth A.; Rideout, Steven L.; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter of the 2021 Home Grounds and Animals PMG. This 2021 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. This publication contains information about prevention and nonchemical control as alternatives to chemical control or as part of an integrated pest management approach. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.
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    2021 Home Grounds PMG - Index
    Askew, Shawn D.; Wycoff, Stephanie B.; Bush, Elizabeth A.; Day, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F.; Frank, Daniel L.; Hansen, Mary Ann; Laub, Curtis A.; McCall, David S.; Miller, Dini M.; Nita, Mizuho; Parkhurst, James A.; Paulson, Sally L.; Pfeiffer, Douglas G.; Rideout, Steven L.; Wilson, James; Yoder, Keith S.; Hong, Chuan X. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter of the 2021 Home Grounds and Animals PMG. This 2021 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. This publication contains information about prevention and nonchemical control as alternatives to chemical control or as part of an integrated pest management approach. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.
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    2021 Horticultural and Forest PMG - Authors
    Askew, Shawn D.; Baudoin, Antonius B.; Bergh, J. Christopher; Chamberlin, Lori; Dary, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F.; Frank, Daniel; Hansen, Mary Ann; Hong, Chuan X.; Johnson, Charles S.; Laub, Curtis A.; McCall, David S.; Nita, Mizuho; Parson, Rachel; Peer, Kyle; Pfeiffer, Douglas G.; Richardson, Robert J.; Salom, Scott M.; Schultz, Peter B.; Wilson, James (Virginia Cooperative Extension, 2021-02-12)
    Horticultural and Forest Crops 2021 Author Contact List
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    2021 Horticultural and Forest PMG - Commercial Small Fruit: Diseases and Insects
    Pfeiffer, Douglas G.; Johnson, Charles S.; Bergh, J. Christopher; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter from the 2021 Horticulture and Forest Pest Management Guide. The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry.
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    2021 Horticultural and Forest PMG - Floral Crops
    Hong, Chuan X.; Schultz, Peter B.; Day, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter from the 2021 Horticulture and Forest Pest Management Guide. The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry.
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    2021 Horticultural and Forest PMG - Hops
    Nita, Mizuho; Pfeiffer, Douglas G.; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter from the 2021 Horticulture and Forest Pest Management Guide. The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry.
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    2021 Horticultural and Forest PMG - Nursery Crops
    Hong, Chuan X.; Schultz, Peter B.; Day, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter from the 2021 Horticulture and Forest Pest Management Guide. The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry.
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    2021 Horticultural and Forest PMG - Pests of Forestry and Christmas Trees
    Day, Eric R.; Salom, Scott M.; Chamberlin, Lori; Peer, Kyle; Hansen, Mary Ann; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter from the 2021 Horticulture and Forest Pest Management Guide. The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry.
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    Allelopathic effects of ferulic, gallic, and vanillic acids on corn (Zea mays L.)
    Abdaoui, Fatima El (Virginia Tech, 1991-01-03)
    Studies on the activity of femlic, gallic, and vanillic acids on germination and growth of corn (Zea mays L.), radish (Raphanus sativus L.), and peanut (Arachis hypogaea L.) showed that the inhibitory effects of these acids were concentration and growth variable dependent. Ten days after treatment, significant reduction in percent germination of the three species occurred with higher phenolic acid treatments, except that gallic acid did not significantly inhibit peanut germination. Among the growth parameters investigated, root elongation and dry weight were more affected than either germination or shoot length and dry weight. Radish and corn were more sensitive than peanut. In two-combination experiments, the interactive effects of phenolic acids on corn germination and shoot growth were generally not significant, indicating an additive effect. Femlic acid, generally, antagonized higher concentrations of vanillic or gallic acids on corn root length and dry weight, suggesting a differential uptake of phenolic acids by corn roots or a limited uptake of gallic and vanillic acids in the presence of ferulic acid. In a soil system, higher and repeated phenolic acid treatments were required to bring about inhibition of corn growth than those which were effective in petri dishes. All levels of the synthetic auxin, 2,4-D (2,4-dichlorophenoxyacetic acid) were effective in reversing the inhibitory effects of 1 mM ferulic acid on corn root length when these two acids were applied in combination. No 2,4-D treatment counteracted 10 mM of ferulic acid. All levels of 2,4-D combined with 1 mM ferulic acid and the mixture of 0.1 nM 2,4-D with 10 mM ferulic acid were antagonistic for corn shoot length. No significant interactions were obtained on corn germination or seedling growth when 2,4-D was combined with gallic acid. Using manometric techniques, no inhibitory effects of ferulic or gallic acids observed on 02 consumption of germinating corn seeds. Ferulic acid did not interfere with water uptake of corn seeds during imbibition and germination. These findings indicate that the phytotoxicity of these acids observed on corn germination and seedling growth are not due to their interference with water uptake and respiratory activity of germinating seeds.
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    Basis for Selectivity of Isoxaben in Ajuga (Ajuga reptans), Wintercreeper (Euonymus fortunie), and Dwarf Burning Bush (Euonymus alatus 'Compacta')
    Salihu, Sydha (Virginia Tech, 1997-01-05)
    Isoxaben is a preemergence herbicide used for broadleaf weed control in turf and ornamentals. Although isoxaben can be used on a number of ornamentals, certain species are injured by isoxaben applications. The objectives of this research were: a) to evaluate the tolerance of ajuga, wintercreeper and dwarf burning bush to isoxaben applications, b) to compare the absorption, translocation and metabolism of isoxaben following root and shoot application in these ornamentals, and c) to examine the effect of isoxaben on glucose incorporation in the roots of these species. Greenhouse and lathhouse studies demonstrated that ajuga was the most sensitive species compared to wintercreeper and dwarf burning bush following root and shoot exposure to isoxaben at 0.84, 1.69 and 3.39 kg ai/ha. Following root and shoot application, isoxaben at 3.39 kg/ha caused approximately 50% shoot injury in ajuga at 2 months after treatment compared to approximately 30% in dwarf burning bush in sand culture. Wintercreeper was not visually injured by any isoxaben rate. Isoxaben at 3.39 kg/ha reduced wintercreeper root weight by 15% following root application and shoot weight by 10% following shoot application. Field studies showed that isoxaben applications made one month after bud-break caused 30 to 45% injury to dwarf burning bush. However, the plants outgrew the injury in the following year. Dwarf burning bush was not injured from applications of isoxaben made at the dormant stage or two months after the bud-break stage. Studies with root-applied radiolabeled isoxaben showed that ajuga and dwarf burning bush had absorbed 34 and 41% of the applied radioactivity, respectively, while wintercreeper had absorbed only 21% at 14 days after treatment (DAT). The percent of absorbed radioactivity which translocated was greater in ajuga (58%) and wintercreeper (50%) than in dwarf burning bush (28%). In the root extracts, metabolism of isoxaben was greater in ajuga than wintercreeper or dwarf burning bush at 3, 7 and 14 DAT. Most of the radioactivity recovered from the shoots of the three species appeared to be polar metabolites of isoxaben, possibly conjugates. In studies with shoot-applied radiolabeled isoxaben, radioactivity recovered from the treated leaf of ajuga increased from 46% of applied at 3 days to 64% at 14 days after treatment. In wintercreeper, the most tolerant species, approximately 40% of the applied radioactivity was recovered in the treated leaf at each harvest date. Radioactivity recovered from the treated leaflet increased from 45 at 3 DAT to 70% at 14 DAT in both growth stages of dwarf burning bush. Ajuga and wintercreeper metabolized isoxaben faster than dwarf burning bush. There was no difference in the metabolism of isoxaben between the two growth stages of dwarf burning bush. Incorporation of glucose in the roots of wintercreeper and dwarf burning bush was not inhibited by isoxaben (1 mM). Approximately 10% inhibition of glucose incorporation by isoxaben was observed in the roots of the sensitive species ajuga.
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    The control of yellow and purple nutsedge (Cyperus esculentus and rotundus) in turfgrass utilizing halosulfuron
    Czarnota, Mark Andrew (Virginia Tech, 1995-10-05)
    Yellow and purple nutsedge are difficult to control worldwide. In turfgrass, the availability of herbicides that provide selective control of these weeds is limited. To address this problem, a sulfonylurea herbicide, halosulfuron, is being developed for the control of both yellow and purple nutsedge. To confirm preliminary results, evaluations of this herbicide were performed in both field and greenhouse studies during 1993 and 1994. The objectives of the field studies were to evaluate halosulfuron for turfgrass tolerance (safety to turfgrass) and efficacy for yellow and purple nutsedge control. Greenhouse studies were performed to determine the extent of translocation of halosulfuron in yellow and purple nutsedge. Four species of turfgrass were evaluated for halosulfuron tolerance: Kentucky bluegrass (Poa pratensis L. 'Plush’), tall fescue (Festuca arundinaceae Schreb. 'Confederate'), bermudagrass (Cynodon dactylon (L.) Pers. '419' and 'Vamont') and zoysiagrass (Zoysia japonica Steud. 'Meyers'). Over a two-year period, injury to these turfgrass species did not exceed 10% and in most cases was non-existent. In these studies, yellow nutsedge control with halosulfuron at 0.14 kg ai/ha averaged 90% after six weeks in the four turfgrasses. However, after six weeks, yellow nutsedge regrowth did occur. Purple nutsedge control was evaluated only in Kentucky bluegrass and was uniformly transplanted into the study area. Purple nutsedge control averaged 96% in Kentucky bluegrass at 6 weeks after treatment. Yellow and purple nutsedge contains a well-developed rhizome/tuber system, and as was seen in several of the studies, have the ability to regrow after herbicide treatment. Two greenhouse studies were designed to determine halosulfuron translocation into the tuber and connecting shoot and through a rhizome into another shoot. In the first study, a tuber was only allowed to develop two shoots from separate buds on the tuber. After a month, one of the shoots was treated with halosulfuron, and control ratings were taken on both shoots. In the second study, a plant was placed in one of two connected pots and allowed to grow. A rhizome from this plant (mother plant) was guided into the connecting pot where a new plant developed. After a month, the mother plant was treated with halosulfuron, and control ratings were taken on both mother and new plant. From both of these tests, there is statistically significant evidence that translocation was occurring through both the tuber and the rhizome. This translocation occurred not only at rates used for nutsedge control but at rates well above and below 0.14 kg ai/ha. More work, however, needs to be performed using radiolabeled tracers or immunological techniques to confirm the movement of halosulfuron in yellow and purple nutsedge. Although regrowth of yellow and purple nutsedge was seen in both field and greenhouse studies, halosulfuron does provide good initial control of both species. Sequential applications of halosulfuron are desirable in poorly established turfgrass.
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    Evaluation of anaerobic soil disinfestation using brewers spent grain and yeast inoculation in  annual hill plasticulture strawberry production
    Liu, Danyang (Virginia Tech, 2021-04-14)
    Anaerobic soil disinfestation (ASD) is a promising alternative to chemical fumigation to control soil-borne plant pathogens and weeds. This research focused on evaluating several locally available carbon sources for ASD on weed control, evaluating the performance of brewers' spent grain (a promising carbon source) under field conditions, and evaluating whether yeast addition enhanced the effectiveness of ASD treatments. A series of greenhouse trials were conducted at the Southern Piedmont AREC (Agricultural Research and Extension Center). The greenhouse trials were conducted in PVC tubes, 20 cm tall and 15 cm in diameter. The first set of trials evaluated ASD conducted over 21-day periods of ASD using locally available carbon sources. The carbon sources included brewer`s spent grain, buckwheat (Fagopyrum esculentum), cowpea (Vigna unguiculata), paper mulch, peanut (Arachis hypogaea) shells, rice bran, sorghum-sudangrass (Sorghum drummondii), and waste coffee grounds applied at 4 mg of C/g of soil. The targeted weed species included common chickweed (Stellaria media (L.) Vill.), redroot pigweed (Amaranthus retroflexus L.), white clover (Trifolium repens L.), and yellow nutsedge (Cyperus esculentus L.). All ASD treatments significantly reduced weed viability compared to the non-treated control. The yeast amendments enhanced weed control over ASD without yeast. The second set of greenhouse trials was focused on ASD using brewer`s spent grain, and on evaluating ASD at the half and one-third carbon dose rates. The target pests were the same weed species in the first set of trials, and Pythium irregulare was added as an additional target pest. This set of trials indicated yeast enhanced addition the effect of BSG in ASD on both weeds and P. irregulare, indicating the potential to reduce carbon input necessary for effective ASD. A follow-up, two seasons, open-field trial conducted over two growing seasons at the Hampton Roads AREC focused on understanding the effects of ASD on weed density and strawberry fruit yield and fruit quality in annual hill strawberry production. The treatments included ASD at standard or half carbon dose rates, with or without yeast. Fumigation (80% chloropicrin + 20% 1,3-dichloropropene) and non-treated plots were used as control groups. Weed suppression with ASD was consistent for most of the broadleaf weed species, and total weed counts were significantly reduced compared to non-treated controls. Yield from ASD with yeast was higher than ASD without yeast and non-treated control in one growing season, while the increase in yield did not occur in another growing season. Yeast may have potentially enhanced the yield effects of ASD but lacked consistency. Yeast may have the potential to enhance ASD effectiveness.
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    Evaluation of plant growth regulators for managing fescue turf along highway rights-of-way
    Vollmer, Joseph Gerard (Virginia Polytechnic Institute and State University, 1989)
    Plant growth regulators (PGR's) including metsulfuron plus mefluidide at 10 plus 140 g ha⁻¹, chlorsulfuron plus mefluidide at 20 plus 140 g ha⁻¹, imazethapyr plus imazapyr at 67.5 plus 2.5, 96.4 plus 3.6, and 115.7 plus 4.3 g ha⁻¹, ACP 2100 at 60, 120, and 180 g ha⁻¹, and DPX L5300 plus mefluidide at 10 plus 140, 20 plus 140, and 70 plus 140 g ha⁻¹ were applied to ‘KY 31’ tall fescue (Festuca arundinacea Schreb.). All rates of imazethapyr plus imazapyr, ACP 2100, and chlorsulfuron plus mefluidide afforded a significantly higher turf quality than metsulfuron plus mefluidide. ACP 2100 at 120 and 180 g ha⁻¹, imazethapyr plus imazapyr, DPX L5300 plus mefluidide at 70 plus 140 g ha⁻¹, and metsulfuron plus mefluidide gave the most consistent seedhead suppression. When treating seven month old tall fescue, DPX L5300 plus mefluidide did not adequately suppress seedhead elongation. Metsulfuron plus mefluidide, regardless of timing, caused excessive injury. All rates of imazethapyr plus imazapyr and the upper rates of ACP 2100 afforded the best turf quality followed by chlorsulfuron plus mefluidide in 1988 to ‘Rebel’ and both years to ‘KY 31’. Red fescue (Festuca rubra L.) quality was best with chlorsulfuron plus mefluidide and the high rate of DPX L5300 plus mefluidide. All other treatments resulted in a poorer quality turf. For all field studies on all turf types, in general, multiple applications were not practical and often caused excessive injury regardless of timing. Root studies conducted in the greenhouse revealed that with one application, imazethapyr plus imazapyr, ACP 2100, and DPX L5300 plus mefluidide provided root dry weights ranging from 0.5 to 0.7 g, which was greater than metsulfuron plus mefluidide, chlorsulfuron plus mefluidide, and the mowed check which afforded root dry weights of 0.1, 0.3, and 0.2, respectively. With two applications ACP 2100 and DPX L5300 plus mefluidide afforded 350, 1100, 200 and 200% greater root volume than metsulfuron plus mefluidide and chlorsulfuron plus mefluidide and 200, 630, 600 and 600% greater root dry weights. Three applications are not recommended. In laboratory studies using ‘KY 31’ tall fescue, mefluidide enhanced the uptake of ¹⁴C-DPX L5300 after 48 hours by as much as 11% and the translocation of ¹⁴C by 8.4% to the young leaves, 9.3% to the old leaves and 6.1% to the culm. Radioactive material concentrated in the tips of leaves. No significant accumulation of ¹⁴C occurred in the crown or roots.
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    Evaluation of Seashore Paspalum in Southeastern Virginia
    Crawford, Claudia (Virginia Tech, 2014-07-23)
    Seashore paspalum (Paspalum vaginatum Sw.) has been successfully grown in warm, humid environments in both the United States and southeastern Asia. In the U.S., seashore paspalum has been planted in parts of North Carolina south to Florida, Texas, California and Hawaii. Very tolerant of low mowing heights, this species has been used primarily for golf courses, but also has applicability as a turf for lawns. High salt tolerance makes it a promising turf for areas near the Chesapeake Bay and the Atlantic Ocean. Research and testing of seashore paspalum in the U.S. has been conducted primarily in Georgia and Florida. Virginia Tech has not conducted any research on this potential new turf species for Virginia. For this project, I have evaluated the adaptability of nine vegetative and three seeded cultivars of seashore paspalum in southeastern Virginia in comparison to Bermuda grass (Cynodon dactylon L.) as an industry standard for comparison. Evaluations of turf cover were made weekly during establishment and at time of spring green-up. Weed competition significantly reduced establishment, with only the vegetative cultivars ‘Sea Star’ and ‘Sea Isle Supreme’ seashore paspalum achieving greater than 65% cover during the first growing season. No cultivar planted by seed successfully established due to weed competition. All seashore paspalum cultivars planted vegetatively survived the winter; however, only Sea Isle Supreme and Sea Star had exceeded 75% turf cover by June 19, 2014, approximately 75 days after breaking dormancy. ‘Yukon’ Bermuda grass achieved an 85% turf cover in the same time frame.
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    Field and laboratory investigations on the efficacy, selectivity, and action of the herbicide clomazone
    Vencill, William K. (Virginia Polytechnic Institute and State University, 1988)
    Clomazone is a recently introduced herbicide for the selective control of grass and broadleaf weeds in soybeans. Field studies were conducted in full-season no-till soybeans to determine the efficacy of clomazone as a preplant and preemergence herbicide. Clomazone applied preemergence provided large crabgrass (Digitaria sanguinalis L.) control equivalent to that of oryzalin applied preplant or preemergence and provided better control of several broadleaf weeds. Control from preplant applications of clomazone was not adequate. Preemergence and preplant incorporated applications of clomazone were compared in conventionally-tilled soybeans. Clomazone efficacy at two depths of incorporation was also investigated. Clomazone applied preemergence generally provided control of large crabgrass and several broadleaf weed species equivalent to preplant incorporated applications. The addition of imazaquin or chlorimuron plus linuron improved smooth pigweed (Amaranthus hybridus L.) control over that provided by clomazone alone. These combinations generally did not improve large crabgrass, jimsonweed (Datura stramonium L.), and common lambsquarters (Chenopodium album L.) control over that of clomazone alone. Shallow incorporation (4 cm) of clomazone provided better weed control than deep incorporations (8 cm). Studies were conducted to evaluate efficacy and to quantify volatilization of three clomazone formulations (emulsifiable concentrate, wettable powder, and a microencapsulated formulation) following soil application. Samples were collected at the first, second, and tenth day after clomazone application. The three clomazone formulations provided control of large crabgrass. Clomazone volatilization was greatest 24 h after application from the emulsifiable concentrate and wettable powder formulations and declined at the second and tenth day after application. Volatilization from the microencapsulated formulation was lower than the other two formulations at all sampling times. Clomazone volatilization was greater from preemergence than preplant incorporated applications. Differential selectivity studies were initiated to determine the absorption, translocation, and metabolism of clomazone in tolerant soybean and smooth pigweed and susceptible redroot pigweed and livid amaranth exposed to foliar and root applied clomazone. Redroot pigweed and livid amaranth absorbed more clomazone through the roots than soybean and smooth pigweed. Absorption of foliar-applied clomazone was limited in all species. Of the clomazone absorbed in all species, most was translocated to the leaf tissue. Two metabolites of clomazone were found. One was determined to be a GS-clomazone conjugate. Differences in clomazone metabolism among species examined were not found. Growth and physiological responses of a normal hybrid ('DeKalb XL67'), a dwarf mutant, and an albino mutant of corn (Zea mays L.) to clomazone and interactions of gibberellin with clomazone on normal corn were examined. The dwarf mutant displayed greater tolerance to clomazone than normal corn. Growth measurements suggested that gibberellin was antagonistic with clomazone.