@article{kohlway_whetten_benson_frampton_2017, title={Response of Turkish and Trojan fir to Phytophthora cinnamomi and P. cryptogea}, volume={32}, ISSN={0282-7581 1651-1891}, url={http://dx.doi.org/10.1080/02827581.2017.1280076}, DOI={10.1080/02827581.2017.1280076}, abstractNote={ABSTRACT Phytophthora root rot, primarily caused by the oomycete Phytophthora cinnamomi, is a large problem for the Christmas tree industry in North Carolina. Fraser fir (Abies fraseri) has no known innate resistance to this pathogen while some exotic fir species, such as Trojan (Abies equi-trojani) and Turkish (Abies bornmuelleriana) fir display varying amounts of resistance. A Phytophthora-resistance screening trial was completed with 1600 seedlings from 12 Turkish and Trojan fir families and Fraser and momi fir (A. firma). Seedlings from each family or species were inoculated with each of eight Phytophthora isolates, six P. cinnamomi and two Phytophthora cryptogea, in an effort to describe variability in isolate aggressiveness. Mortality was assessed as percent shoot necrosis bi-weekly for 16 weeks. Overall, rankings of resistance in fir species confirmed previous single-isolate-based results; momi fir was the most resistant, followed by Turkish, Trojan, and Fraser fir. P. cinnamomi isolates were generally more aggressive than P. cryptogea isolates. The two P. cryptogea isolates resulted in 5.6% and 0.8% mortality on Turkish fir, and 10.9% and 6.7% mortality on Trojan fir, the first reported resistance screen of these host-pathogen combinations. Pearson’s correlation testing identified a high degree of correlation between most isolates and overall mean mortality. Turkish and Trojan fir families appear to possess resistance to Phytophthora species common in North Carolina.}, number={5}, journal={Scandinavian Journal of Forest Research}, publisher={Informa UK Limited}, author={Kohlway, W. H. and Whetten, R. W. and Benson, D. M. and Frampton, J.}, year={2017}, month={Feb}, pages={406–411} }
 @article{pettersson_frampton_rönnberg_shew_benson_kohlway_escanferla_cubeta_2016, title={Increased diversity of Phytophthora species in Fraser fir Christmas tree plantations in the Southern Appalachians}, volume={32}, ISSN={0282-7581 1651-1891}, url={http://dx.doi.org/10.1080/02827581.2016.1265144}, DOI={10.1080/02827581.2016.1265144}, abstractNote={ABSTRACT Phytophthora root rot (PRR) disease afflicts significant economic losses to the Fraser fir Christmas tree industry. In previous surveys conducted in 1972 and from 1997 to 1998 in North Carolina, the incidence of PRR was ∼9.5% with Phytophthora cinnamomi identified as the predominant causal species isolated from infected roots of Fraser fir. Due to increased use of out-of-state planting stock since 2000, we suspected increased diversity of Phytophthora species. During 2014, we surveyed Fraser fir Christmas tree plantations in the Southern Appalachians of North Carolina, Tennessee and Virginia to determine the occurrence of pathogenic root-rotting species of Phytophthora. A weighted sampling strategy based on Christmas tree acreage was deployed to collect symptomatic Fraser fir roots from 103 commercial production fields in 14 counties. Six species of Phytophthora were isolated from infected roots sampled from 82 sites in 13 counties. Phytophthora cinnamomi, P. cryptogea and P. pini represented 70.3%, 23.1% and 1.1% of the 91 isolates. Phytophthora citrophthora, P. europaea and P. sansomeana accounted for the remaining 5.5% of the isolates and have not been identified in previously published Fraser fir surveys conducted in the region. The pathogenicity of P. citrophthora on Fraser fir was confirmed based on completion of Koch’s postulates.}, number={5}, journal={Scandinavian Journal of Forest Research}, publisher={Informa UK Limited}, author={Pettersson, M. and Frampton, J. and Rönnberg, J. and Shew, H. D. and Benson, D. M. and Kohlway, W. H. and Escanferla, M. E. and Cubeta, M. A.}, year={2016}, month={Dec}, pages={412–420} }
 @article{loyd_benson_ivors_2014, title={Phytophthora Populations in Nursery Irrigation Water in Relationship to Pathogenicity and Infection Frequency of Rhododendron and Pieris}, volume={98}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-11-13-1157-re}, abstractNote={ Phytophthora spp. are waterborne plant pathogens that are commonly found in streams, rivers, and reclaimed irrigation water. Rhododendron and Pieris trap plants at two commercial nurseries were irrigated with water naturally infested with Phytophthora spp. during the 2011 and 2012 growing seasons to assess the frequency of disease. Phytophthora spp. were consistently recovered from water samples at every collection time but detected on only 2 of the 384 trap plants during the two growing seasons. Pathogenicity assays proved that Phytophthora hydropathica and Phytophthora taxon PgChlamydo, commonly recovered taxa in irrigation water at the nurseries, were foliar pathogens of Rhododendron and Pieris; however, neither species was able to cause root rot on these same hosts. Overall, Phytophthora spp.-infested irrigation water did not act as a primary source of infection on Rhododendron and Pieris, even though foliar pathogenic species of Phytophthora were present in the water. }, number={9}, journal={PLANT DISEASE}, author={Loyd, A. L. and Benson, D. M. and Ivors, K. L.}, year={2014}, month={Sep}, pages={1213–1220} }
 @article{olson_jeffers_ivors_steddom_williams-woodward_mmbaga_benson_hong_2013, title={Diversity and mefenoxam sensitivity of Phytophthora spp. associated with the ornamental horticulture industry in the Southeastern United States}, volume={97}, number={1}, journal={Plant Disease}, author={Olson, H. A. and Jeffers, S. N. and Ivors, K. L. and Steddom, K. C. and Williams-Woodward, J. L. and Mmbaga, M. T. and Benson, D. M. and Hong, C. X.}, year={2013}, pages={86–92} }
 @article{frampton_isik_benson_2013, title={Genetic variation in resistance to Phytophthora cinnamomi in seedlings of two Turkish Abies species}, volume={9}, ISSN={["1614-2942"]}, DOI={10.1007/s11295-012-0529-0}, number={1}, journal={TREE GENETICS & GENOMES}, publisher={Springer Nature}, author={Frampton, John and Isik, Fikret and Benson, D. Michael}, year={2013}, month={Feb}, pages={53–63} }
 @article{olson_benson_2013, title={Host specificity and variations in aggressiveness of North Carolina isolates of Phytophthora cryptogea and P. drechsleri in greenhouse ornamental plants}, volume={97}, number={1}, journal={Plant Disease}, author={Olson, H. A. and Benson, D. M.}, year={2013}, pages={74–80} }
 @inproceedings{ganci_benson_ivors_2013, title={Susceptibility of commercial boxwood taxa to Cylindrocladium buxicola (c)}, volume={1014}, DOI={10.17660/actahortic.2013.1014.83}, booktitle={Proceedings of the international plant propagators' society}, author={Ganci, M. and Benson, D. M. and Ivors, K. L.}, year={2013}, pages={369–370} }
 @article{frampton_benson_2012, title={Seedling resistance to Phytophthora cinnamomi in the genus Abies}, volume={69}, number={7}, journal={Annals of Forest Science}, author={Frampton, J. and Benson, D. M.}, year={2012}, pages={805–812} }
 @article{richter_ivors_shi_benson_2011, title={Cellulase Activity as a Mechanism for Suppression of Phytophthora Root Rot in Mulches}, volume={101}, ISSN={["0031-949X"]}, DOI={10.1094/phyto-04-10-0125}, abstractNote={ Wood-based mulches are used in avocado production and are being tested on Fraser fir for reduction of Phytophthora root rot, caused by Phytophthora cinnamomi. Research with avocado has suggested a role of microbial cellulase enzymes in pathogen suppression through effects on the cellulosic cell walls of Phytophthora. This work was conducted to determine whether cellulase activity could account for disease suppression in mulch systems. A standard curve was developed to correlate cellulase activity in mulches with concentrations of a cellulase product. Based on this curve, cellulase activity in mulch samples was equivalent to a cellulase enzyme concentration of 25 U ml–1 or greater of product. Sustained exposure of P. cinnamomi to cellulase at 10 to 50 U ml–1 significantly reduced sporangia production, but biomass was only reduced with concentrations over 100 U ml–1. In a lupine bioassay, cellulase was applied to infested soil at 100 or 1,000 U ml–1 with three timings. Cellulase activity diminished by 47% between 1 and 15 days after application. Cellulase applied at 100 U ml–1 2 weeks before planting yielded activity of 20.08 μmol glucose equivalents per gram of soil water (GE g–1 aq) at planting, a level equivalent to mulch samples. Cellulase activity at planting ranged from 3.35 to 48.67 μmol GE g–1 aq, but no treatment significantly affected disease progress. Based on in vitro assays, cellulase activity in mulch was sufficient to impair sporangia production of P. cinnamomi, but not always sufficient to impact vegetative biomass. }, number={2}, journal={PHYTOPATHOLOGY}, author={Richter, Brantlee Spakes and Ivors, Kelly and Shi, Wei and Benson, D. M.}, year={2011}, month={Feb}, pages={223–230} }
 @article{olson_benson_2011, title={Characterization of Phytophthora spp. on floriculture crops in North Carolina}, volume={95}, number={8}, journal={Plant Disease}, author={Olson, H. A. and Benson, D. M.}, year={2011}, pages={1013–1020} }
 @article{richter_benson_ivors_2011, title={Microbial Profiling of Cultural Systems for Suppression of Phytophthora Root Rot in Fraser Fir}, volume={95}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-03-10-0238}, abstractNote={ Phytophthora root rot of Fraser fir, caused by several Phytophthora spp., is a severe problem in Christmas tree production. Since fungicides are not economically viable for disease management in field plantings and host resistance is not available, cultural control methods were investigated. Mulches, dairy compost, and soil pH adjustment were tested at five field sites in North Carolina. Treatments included wood chips, wood chips plus compost, or pine bark as raised beds, and compost or sulfur tilled into soil. Soil and mulch microbial populations were characterized by dilution plating and calculation of a log series diversity index, and by enzyme analyses at 5, 12, 17, and 24 months after planting. Bacterial and fungal counts, microbial activity, and cellulase activity were higher in mulch than in soil at all sites and times (P < 0.01), and generally did not differ among mulch types or among soils. Treatments significantly affected disease ratings and tree survival at three of five sites, with one or more mulch treatments yielding lower disease ratings and greater survival than controls. Tree mortality at each time point varied significantly with cellulase activity in the upper root zone (P = 0.005). Other biological variables did not show significant relationships with disease ratings or mortality. }, number={5}, journal={PLANT DISEASE}, author={Richter, B. S. and Benson, D. M. and Ivors, K. L.}, year={2011}, month={May}, pages={537–546} }
 @article{olson_carbone_benson_2011, title={Phylogenetic history of Phytophthora cryptogea and P. drechsleri Isolates from floriculture crops in North Carolina greenhouses}, volume={101}, number={11}, journal={Phytopathology}, author={Olson, H. A. and Carbone, I. and Benson, D. M.}, year={2011}, pages={1373–1384} }
 @article{xu_gleason_mueller_esker_bradley_buck_benson_dixon_monteiro_2008, title={Overwintering of Sclerotium rolfsii and S-rolfsii var. delphinii in different latitudes of the United States}, volume={92}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS-92-5-0719}, abstractNote={ Previously known only from the southern United States, hosta petiole rot recently appeared in the northern United States. Sclerotium rolfsii var. delphinii is believed to be the predominant petiole rot pathogen in the northern United States, whereas S. rolfsii is most prevalent in the southern United States. In order to test the hypothesis that different tolerance to climate extremes affects the geographic distribution of these fungi, the survival of S. rolfsii and S. rolfsii var. delphinii in the northern and southeastern United States was investigated. At each of four locations, nylon screen bags containing sclerotia were placed on the surface of bare soil and at 20-cm depth. Sclerotia were recovered six times from November 2005 to July 2006 in North Dakota and Iowa, and from December 2005 to August 2006 in North Carolina and Georgia. Survival was estimated by quantifying percentage of sclerotium survival on carrot agar. Sclerotia of S. rolfsii var. delphinii survived until at least late July in all four states. In contrast, no S. rolfsii sclerotia survived until June in North Dakota or Iowa, whereas 18.5% survived until August in North Carolina and 10.3% survived in Georgia. The results suggest that inability to tolerate low temperature extremes limits the northern range of S. rolfsii. }, number={5}, journal={PLANT DISEASE}, author={Xu, Z. and Gleason, M. L. and Mueller, D. S. and Esker, P. D. and Bradley, C. A. and Buck, J. W. and Benson, D. M. and Dixon, P. M. and Monteiro, J. E. B. A.}, year={2008}, month={May}, pages={719–724} }
 @article{warfield_hwang_benson_2008, title={Phytophthora blight and dieback in North Carolina nurseries during a 2003 survey}, volume={92}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-92-3-0474}, abstractNote={ A survey of 14 nurseries growing hybrid rhododendron, Pieris spp., or Viburnum spp. was conducted as part of the 2003 Sudden Oak Death Pilot National Survey to determine if Phytophthora ramorum, the causal agent of sudden oak death, had been introduced to nurseries in North Carolina. Over 220,000 hybrid rhododendrons, 1,700 plants of Pieris spp., and 2,800 plants of Viburnum spp. were surveyed. Across nurseries, blight and dieback incidence averaged 2.4% for Pieris spp. and 10% for rhododendron. P. ramorum was not recovered by isolation or detected by polymerase chain reaction in the 347 plant samples collected. Three species of Phytophthora were isolated from hybrid rhododendron and Pieris spp., but no Phytophthora isolates were recovered from Viburnum spp. P. citricola and P. cambivora were isolated most frequently (61 and 39 isolates, respectively), while 2 isolates of P. cactorum were recovered. Occasionally, two Phytophthora spp. were found in the same block of rhododendrons within a nursery, but only one species was recovered from an individual plant. Most cultivars of rhododendron surveyed, including ‘English Roseum,’ ‘Nova Zembla,’ and ‘Roseum Elegans,’ had less than 0.5% incidence of Phytophthora blight and dieback, whereas ‘Lee's Dark Purple’ had 3.8% disease incidence across all nurseries surveyed. }, number={3}, journal={PLANT DISEASE}, author={Warfield, C. Y. and Hwang, J. and Benson, D. M.}, year={2008}, month={Mar}, pages={474–481} }
 @article{olson_benson_2007, title={Induced systemic resistance and the role of binucleate Rhizoctonia and Trichoderma hamatum 382 in biocontrol of Botrytis blight in geranium}, volume={42}, ISSN={["1090-2112"]}, DOI={10.1016/j.biocontrol.2007.05.009}, abstractNote={Three root-colonizing fungi, binucleate Rhizoctonia (BNR) isolates BNR621 and P9023 and Trichoderma hamatum isolate 382 (T382), were studied for suppression of Botrytis blight in geranium by induction of host systemic resistance. Resistance to Botrytis blight was observed in geraniums transplanted into potting mix amended with formulations of P9023 and T382 2 weeks prior to inoculation with Botrytis cinerea when grown under environments either highly or less conducive to disease development. In the less conducive environment, P9023 and T382 provided protection equal to (P < 0.0001) the fungicide control. Specific stages in infection by B. cinerea were tested by counting germination of conidia in leaf extracts or by assessing lesion size in detached leaves taken from BNR- and T382-treated geraniums. No differences in conidial germination were observed. Lesion area results depended on time between application of inducing agents and detachment of leaves for inoculation. In geranium leaves detached and inoculated 7 days after topdressing with a Pesta formulation of BNR621 and P9023, AUDPC calculated from lesion area was smaller (P < 0.0001) than T382 and the inoculated control. Whereas, leaves detached and inoculated 14 days after topdressing with a formulation of T382 had a smaller (P < 0.0001) AUDPC from lesion area than plants treated with BNR621. Restriction of lesion development may play a role in the suppression of Botrytis blight in geranium. Our results may be the first to demonstrate induced systemic resistance by BNR fungi to a foliar pathogen and support additional research into use of T382 in an integrated management program for B. cinerea.}, number={2}, journal={BIOLOGICAL CONTROL}, author={Olson, Heather A. and Benson, D. Michael}, year={2007}, month={Aug}, pages={233–241} }
 @article{benson_sidebottom_moody_2006, title={Control of Phytophthora root rot in field plantings of Fraser fir-with fosetyl-al and mefenoxam}, ISBN={1535-1025}, DOI={10.1094/php-2006-0331-01-rs}, abstractNote={ Fungicides were evaluated for control of Phytophthora root rot for five growing seasons in two field plantings of Fraser fir (Abies fraseri) affected by Phytophthora cinnamomi in western North Carolina. At the first site, which had a fairly well-drained soil, treatment programs with Aliette (5 lb/100 gal, three applications per year), Subdue Maxx (3.7 fl oz/1.15 gal/1000 ft2, two applications per year), and Subdue GR (5.75 lb/1000 ft2, two applications per year) maintained low rates of mortality (< 10%) for three growing seasons, whereas tree mortality in the untreated plots reached 13 and 37% by the second and third growing seasons, respectively. At the second site, which was in a flood plain, disease did not develop during the first 2.5 years, even in untreated control plots. However, mortality increased rapidly following several high-rainfall events, but none of the fungicides had any effect on disease development. Apparently, at least under conditions not overly conducive to the disease, the fungicide treatment programs can delay the onset of high mortality rates caused by P. cinnamomi in Fraser fir for up to three growing seasons. }, journal={Plant Health Progress}, author={Benson, D. M. and Sidebottom, J. R. and Moody, J.}, year={2006}, pages={1} }
 @article{benson_grand_vernia_gottwald_2006, title={Temporal and spatial epidemiology of Phytophthora root rot in Fraser fir plantations}, volume={90}, ISSN={["1943-7692"]}, DOI={10.1094/PD-90-1171}, abstractNote={ In 1999, 19 plots of Fraser fir (Abies fraseri) with a disease focus were established in commercial plantings grown for Christmas tree production in the mountains of five western North Caro-lina counties. Progress of Phytophthora root rot caused by Phytophthora cinnamomi as estimated by mortality was followed in each plot over 3 to 4 years in an attempt to understand dispersal of inoculum. Slope, aspect, and field production age at the time plots were established were recorded. Rainfall estimated from National Weather Service stations each growing season also was recorded. The relationship of site parameters and rainfall to dispersal and disease was investigated. Disease incidence and mortality were assessed in June and September each year for 3 or 4 years depending on plot. Phytophthora root rot as estimated by mortality counts over time in a logistic regression model progressed in only five of 19 plots over 3 years. None of the site parameters correlated with mortality data, although slightly more disease was found in plots with a north aspect. Rainfall was below normal in the 3 years of the study and did not correlate with mortality in any year. Lack of disease progress in the majority of plots was attributed to drought conditions in the region. In the five plots where mortality increased over time, spatial analysis suggested an aggregated pattern of diseased plants. Aggregation was apparent but not very strong among nearest neighbors, but was considerably stronger among groups of trees within a local area. This aggregation within groups was stronger when larger group sizes were examined by beta-binomial analysis. A spatial analysis by distance indices method (SADIE) indicated the presence of secondary clusters occurring several meters away from the main focus. A stochastic model also was employed that indicated a combination of spatial processes were likely involved, specifically a tendency toward spread within a local area, but not necessarily to the nearest neighboring trees, combined with an influence of background inoculum that could not be accounted for within local areas and may have come from external sources. Thus, all sources of inoculum including infected planting stock, inoculum in soil, infected trees, and contaminated equipment were equally important in epidemics of Phytophthora root rot in Fraser fir and dispersal of P. cinnamomi. }, number={9}, journal={PLANT DISEASE}, author={Benson, D. M. and Grand, L. F. and Vernia, C. S. and Gottwald, T. R.}, year={2006}, month={Sep}, pages={1171–1180} }
 @article{hwang_benson_2005, title={Identification, mefenoxam sensitivity, and compatibility type of Phytophthora spp. attacking floriculture crops in North Carolina}, volume={89}, ISSN={["1943-7692"]}, DOI={10.1094/PD-89-0185}, abstractNote={ Phytophthora isolates were collected from floriculture crops grown in commercial greenhouses in North Carolina for species identification, compatibility type determination, and mefenoxam sensitivity tests. Isolation from 41 symptomatic plant species at 29 production locations resulted in 483 isolates from eight crops at seven locations. Phytophthora cryptogea (184 isolates) was recovered from dusty miller and gerbera daisy. All isolates of P. cryptogea were insensitive or intermediate in sensitivity to mefenoxam at 1 μg a.i./ml and were A1 compatibility type. P. nicotianae (273 isolates) was isolated from African violet, lavender, pansy, petunia, and vinca. Of these isolates, 21% were insensitive to mefenoxam at either 1 or 100 μg a.i./ml. Isolates of P. nicotianae from five locations were A2 compatibility type, whereas isolates on pansy at one location were A1 compatibility type. English ivy grown at two locations was infected with P. palmivora. All 26 isolates of P. palmivora were sensitive to mefenoxam and were A1 compatibility type. Mating type and mefenoxam sensitivity were uniform among isolates of P. nicotianae and P. palmivora from a given crop at a given location, suggesting that epidemics within a location may have originated from a single source of inoculum. }, number={2}, journal={PLANT DISEASE}, author={Hwang, J and Benson, DM}, year={2005}, month={Feb}, pages={185–190} }
 @article{daughtrey_benson_2005, title={Principles of plant health management for ornamental plants}, volume={43}, ISSN={["1545-2107"]}, DOI={10.1146/annurev.phyto.43.040204.140007}, abstractNote={ Economic, environmental, and technological influences complicate the task of achieving disease-free products in the ornamentals industry. Integrated pest management (IPM) is a cornerstone of floriculture and nursery crop production: strategies include sanitation, clean stock, host resistance, and control through biological, cultural, environmental, chemical, and regulatory means. Sanitation measures and cultural controls must keep pace with new production technologies. Clean stock programs are used for many crops that are propagated vegetatively. Breeding, selection, and biotechnology provide crops resistant to pathogens. Offshore production for economic competitiveness can introduce pathogens that make regulatory programs necessary. New biocontrol and chemical products continue to improve control while meeting the requirement for minimal environmental impact. Continual introduction of new crops and new production technologies creates new opportunities for pathogens to exploit, such that new disease management tactics must be discovered and old ones rediscovered to achieve optimum health management for ornamentals. }, journal={ANNUAL REVIEW OF PHYTOPATHOLOGY}, author={Daughtrey, ML and Benson, DM}, year={2005}, pages={141–169} }
 @inproceedings{frampton_benson_li_brahan_hudson_potter_2005, title={Seedling resistance to Phytophthora cinammomi in the Genus Abies}, booktitle={Proceedings of the 28th Southern Forest Tree Improvement Conference}, author={Frampton, J. and Benson, D. M. and Li, J. and Brahan, A. M. and Hudson, E. E. and Potter, K. M.}, year={2005}, pages={146–147} }
 @article{fichtner_benson_diab_shew_2004, title={Abiotic and biological suppression of Phytophthora parasitica in a horticultural medium containing composted swine waste}, volume={94}, ISSN={["1943-7684"]}, DOI={10.1094/PHYTO.2004.94.7.780}, abstractNote={ Horticultural potting media have been amended with compost to enhance biological suppression and with Al2(SO4)3 to enhance abiotic suppression of plant pathogens, but these factors have not been simultaneously incorporated into the same medium. In this study, the efficacy of aluminum (Al)-amended potting medium containing 20% composted swine waste (CSW) was assessed for control of Phytophthora parasitica (syn. P. nicotianae), a soilborne pathogen causing damping-off of many horticultural bedding plants. Steamed and unsteamed media were amended with no Al or Al at 0.0079 g of Al g-1 of medium with an Al2(SO4)3 solution at either pH 4 or pH 6. Infested leaf disks were buried for 2-day durations beginning 0, 6, 13, and 21 days after Al amendment. The number of sporangia produced on infested leaf disks was assessed. A similar experiment was conducted to determine the effect of steaming and Al amendments on pathogen populations. Medium treated with the pH 4 solution consistently reduced sporangia production between 38 and 65% on day 0, but no Al effect was noted at subsequent time points. The pH 6 amendment did not consistently affect sporangia production. Exchangeable Al levels decreased over time, and abiotic suppression was only observed at >2 μM Al g-1 of medium. Pathogen populations were occasionally affected by steaming and Al. Sporangia production in unsteamed medium was reduced by 50% on leaf disks buried on days 6, 13, and 21, but not on day 0. Al amendment of a 20% CSW potting medium enhanced suppression of P. parasitica and abiotic suppression occurred before biological suppression developed. }, number={7}, journal={PHYTOPATHOLOGY}, author={Fichtner, EJ and Benson, DM and Diab, HG and Shew, HD}, year={2004}, month={Jul}, pages={780–788} }
 @article{frampton_benson_2004, title={Phytophthora root rot mortality in fraser fir seedlings}, volume={39}, number={5}, journal={HortScience}, author={Frampton, J. and Benson, D. M.}, year={2004}, pages={1025–1026} }
 @article{lamour_daughtrey_benson_hwang_hausbeck_2003, title={Etiology of Phytophthora drechsleri and P-nicotianae (=P. parasitica) diseases affecting floriculture crops}, volume={87}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS.2003.87.7.854}, abstractNote={ Phytophthora nicotianae and P. drechsleri isolates (n = 413) recovered from eight floricultural hosts at 11 different production sites were described according to compatibility type, resistance to mefenoxam, and amplified fragment length polymorphism (AFLP) profiles. Sample sizes ranged from 2 to 120. In all cases, isolates recovered from a single facility had the same compatibility type and resistance to mefenoxam. AFLP analysis indicated that six clonal lineages of P. nicotianae and two clonal lineages of P. drechsleri were responsible for the 11 epidemics and that isolates recovered from the same facility were identical. A single clone of P. nicotianae was recovered from snapdragons at two field production sites in the southeastern United States receiving seedlings from the same source. This clone persisted at one site from 2000 to 2001. Another clone was recovered from verbena at three separate greenhouse facilities where one facility was supplying verbena to the other two. These results suggest that asexual reproduction of these pathogens plays an important role in epidemics and spread may occur between distant facilities via movement of plants. }, number={7}, journal={PLANT DISEASE}, author={Lamour, KH and Daughtrey, ML and Benson, DM and Hwang, J and Hausbeck, MK}, year={2003}, month={Jul}, pages={854–858} }
 @article{hwang_benson_2003, title={Expression of induced systemic resistance in poinsettia cuttings against Rhizoctonia stem rot by treatment of stock plants with binucleate Rhizoctonia}, volume={27}, ISSN={["1049-9644"]}, DOI={10.1016/S1049-9644(02)00185-8}, abstractNote={Three cultivars of poinsettia (V14 Glory, Freedom Red, and Angelica White) were evaluated for induction of host resistance to Rhizoctonia stem rot in cuttings acquired from stock plants treated with binucleate Rhizoctonia (BNR) in a Pesta formulation. Resistance to stem rot in cuttings of V14 Glory was induced within 7 days of treatment with BNR while Freedom Red and Angelica White did not express resistance until 10 or more days after application of BNR to stock plants. None of the cultivars expressed resistance to stem rot when cuttings were taken from stock plants that were treated with BNR for only 3 or 5 days before propagation. Population dynamics of BNR on poinsettia root tissue were consistent with the expression of induced resistance. A dramatic increase of root colonization by BNR was observed in all cultivars between day 5 and 7. The integrated use of both BNR and Burkholderia cepacia, previously characterized as a stem rot control agent during poinsettia propagation, was evaluated to test for enhanced resistance against stem rot. No additive effect on stem rot control was observed when cuttings taken from stock plants treated with BNR were propagated in rooting strips treated with B. cepacia compared to cuttings propagated in root strips treated with B. cepacia alone. Our results may be the first to demonstrate induced systemic resistance by BNR fungi during vegetation propagation where the biocontrol agent applied to roots of a stock plant was able to protect cuttings from Rhizoctonia solani during propagation.}, number={1}, journal={BIOLOGICAL CONTROL}, author={Hwang, J and Benson, DM}, year={2003}, month={May}, pages={73–80} }
 @article{diab_hu_benson_2003, title={Suppression of Rhizoctonia solani on impatiens by enhanced microbial activity in composted swine waste-amended potting mixes}, volume={93}, ISSN={["0031-949X"]}, DOI={10.1094/PHYTO.2003.93.9.1115}, abstractNote={ Peat moss-based potting mix was amended with either of two composted swine wastes, CSW1 and CSW2, at rates from 4 to 20% (vol/vol) to evaluate suppression of pre-emergence damping-off of impatiens (Impatiens balsamina) caused by Rhizoctonia solani (anastomosis group-4). A cucumber bioassay was used prior to each impatiens experiment to monitor maturity of compost as the compost aged in a curing pile by evaluating disease suppression toward both Pythium ultimum and R. solani. At 16, 24, 32, and 37 weeks after composting, plug trays filled with compost-amended potting mix were seeded with impatiens and infested with R. solani to determine suppression of damping-off. Pre-emergence damping-off was lower for impatiens grown in potting mix amended with 20% CSW1 than in CSW2-amended and nonamended mixes. To identify relationships between disease suppression and microbial parameters, samples of mixes were collected to determine microbial activity, biomass carbon and nitrogen, functional diversity, and population density. Higher rates of microbial activity were observed with increasing rates of CSW1 amendment than with CSW2 amendments. Microbial biomass carbon and nitrogen also were higher in CSW1-amended mixes than in CSW2-amended potting mixes 1 day prior to seeding and 5 weeks after seeding. Principal component analysis of Biolog-GN2 profiles showed different functional diversities between CSW1- and CSW2-amended mixes. Furthermore, mixes amended with CSW1 had higher colony forming units of fungi, endospore-forming bacteria, and oligotrophic bacteria. Our results suggest that enhanced microbial activity, functional and population diversity of stable compost-amended mix were associated with suppressiveness to Rhizoctonia damping-off in impatiens. }, number={9}, journal={PHYTOPATHOLOGY}, author={Diab, HG and Hu, S and Benson, DM}, year={2003}, month={Sep}, pages={1115–1123} }
 @article{hwang_benson_2002, title={Biocontrol of Rhizoctonia stem and root rot of poinsettia with Burkholderia cepacia and binucleate Rhizoctonia}, volume={86}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS.2002.86.1.47}, abstractNote={ Strategies for applying Burkholderia cepacia (strain 5.5B) and Pesta formulations of binucleate Rhizoctonia (BNR) isolates (BNR621 and P9023) were evaluated for biocontrol of Rhizoctonia stem and root rot of poinsettia caused by R. solani. During propagation, one application of B. cepacia suppressed stem rot, while application of either isolate of BNR did not. In contrast, after transplanting rooted poinsettias, one application of either BNR isolate was more effective for suppression of stem and root rot than application of B. cepacia. Sequential application of B. cepacia at propagation followed by a BNR isolate at transplanting was more effective over the crop production cycle than multiple applications of one biocontrol agent or combination application of both biocontrol agents. Root colonization by both biocontrol agents after transplanting rooted poinsettias was affected by application strategy. The least root colonization by both biocontrol agents occurred in the combination application. The highest root colonization by the BNR isolates was observed in the sequential application that provided the most effective disease control. Application of different biocontrol agents during the different production phases of poinsettia was effective for disease control, but understanding the interaction between biocontrol agents and root colonization was important to develop the best application strategy. }, number={1}, journal={PLANT DISEASE}, author={Hwang, J and Benson, DM}, year={2002}, month={Jan}, pages={47–53} }
 @article{hwang_chilton_benson_2002, title={Pyrrolnitrin production by Burkholderia cepacia and biocontrol of Rhizoctonia stem rot of poinsettia}, volume={25}, ISSN={["1049-9644"]}, DOI={10.1016/S1049-9644(02)00044-0}, abstractNote={Pyrrolnitrin production by Burkholderia cepacia strain 5.5B was closely related to suppression of stem rot of poinsettia caused by Rhizoctonia solani. Selected strains RR 13-1 and UV 19-4, which produced significantly less pyrrolnitrin than the parent strain 5.5B, lost the ability to control stem rot completely. Selected strain RR 21-2 produced the same level of pyrrolnitrin as strain 5.5B and was as effective as strain 5.5B in stem rot control. The effect of medium type and initial pH of medium on pyrrolnitrin production by B. cepacia was investigated to improve efficacy of biocontrol. More pyrrolnitrin was accumulated when the initial pH was adjusted to 5.8 than 6.8. With an initial pH of 5.8, strains of B. cepacia produced more pyrrolnitrin in a nutrient broth medium than in a minimum salts medium. Pyrrolnitrin was the major factor in biocontrol of Rhizoctonia stem rot of poinsettia by B. cepacia. Improvement in biocontrol efficacy may be possible by adjusting culture conditions to optimize pyrrolnitrin production.}, number={1}, journal={BIOLOGICAL CONTROL}, author={Hwang, J and Chilton, WS and Benson, DM}, year={2002}, month={Sep}, pages={56–63} }
 @book{jones_benson_2001, title={Diseases of woody ornamentals and trees in nurseries}, publisher={St. Paul, MN: APS Press}, author={Jones, R. K. and Benson, D. M.}, year={2001} }
 @article{honeycutt_benson_2001, title={Formulation of binucleate Rhizoctonia spp. and biocontrol of Rhizoctonia solani on impatiens}, volume={85}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS.2001.85.12.1241}, abstractNote={ Isolates BNR621 and P9023 of binucleate Rhizoctonia spp. (BNR) in Pesta and rice flour formulations were evaluated for control of preemergence damping-off of impatiens caused by R. solani. Amendment of a soilless potting mix with the formulations at 0.47% (vol:vol) 3 days prior to seeding and infesting did not improve control compared to amendment 1 day prior to seeding and infesting regardless of whether the moistened amended potting mix was stored in closed plastic bags or in plug trays under a mist system. BNR fungi were no more effective in biocontrol of R. solani in formulations amended at 0.9%. Control of damping-off was comparable but not consistent between formulations of BNR fungi and the fungicide thiophanatemethyl. Damping-off was controlled better with formulations of BNR fungi than with SoilGard based on Trichoderma virens. Shelf life of Pesta and rice flour formulations at 4°C was determined by assessing viability of BNR isolates over time. Viability of the BNR isolates, measured as CFU/g of formulation, declined to approximately 68 to 79% of the original propagule concentration after 6 months in Pesta and rice flour formulations, with the greatest decline in the first 2 months. Shelf life of BNR isolates in formulation significantly affected control of preemergence damping-off but was isolate dependent. Preemergence damping-off was only 5 to 7% with fresh formulations but increased to 30 to 50% with 4-month-old formulations. Controlled atmospheres, maintained with saturated salt solutions, were established to measure the effect of water activity on shelf life of formulations. Water activities (aw) of 0.12 and 0.33 aw enhanced BNR survival in formulations by approximately 2 to 3 months compared with aw of 0.53 and 0.75 aw. Storage of Pesta and rice flour formulations at 4°C significantly improved BNR survival by 4 to 5 months compared with storage at 25°C. These results suggest that improved shelf life of BNR isolates is needed before formulated products can be developed for biocontrol of preemergence damping-off. }, number={12}, journal={PLANT DISEASE}, author={Honeycutt, EW and Benson, DM}, year={2001}, month={Dec}, pages={1241–1248} }
 @article{elliott_jardin_batson_caceres_brannen_howell_benson_conway_rothrock_schneider_et al._2001, title={Viability and stability of biological control agents on cotton and snap bean seeds}, volume={57}, ISSN={1526-498X 1526-4998}, url={http://dx.doi.org/10.1002/ps.342}, DOI={10.1002/ps.342}, abstractNote={Abstract}, number={8}, journal={Pest Management Science}, publisher={Wiley}, author={Elliott, Monica L and Jardin, Elizabeth A Des and Batson, William E and Caceres, Jacobo and Brannen, Philip M and Howell, Charles R and Benson, D Michael and Conway, Kenneth E and Rothrock, Craig S and Schneider, Raymond W and et al.}, year={2001}, pages={695–706} }
 @article{burns_benson_2000, title={Biocontrol of damping-off of Catharanthus roseus caused by Pythium ultimum with Trichoderma virens and binucleate Rhizoctonia fungi}, volume={84}, ISSN={["1943-7692"]}, DOI={10.1094/pdis.2000.84.6.644}, abstractNote={ Four isolates of Trichoderma (Gliocladium) virens (G-45, G-65, G-85, and G-93) and two isolates of binucleate Rhizoctonia spp. (BNR621 and P9023) were evaluated for biocontrol of preemergence damping-off of Catharanthus roseus (vinca) caused by Pythium ultimum. Putative biocontrol agents were amended to a soilless mix 1, 3, or 6 days prior to seeding and pathogen infestation to determine if colonization of the mix before infestation was important for biocontrol efficacy. Biocontrol of preemergence damping-off of vinca with the four isolates of T. virens was variable. Only isolate G-93 gave control of preemergence damping-off (10 to 18% disease) regardless of the length of time the mix was amended prior to seeding and infestation compared to the infested control (43% disease). In contrast, preemergence damping-off was 10 to 15% with SoilGard (based on isolate GL-21 of T. virens). For isolate G-65, preemergence damping-off of vinca was 0% in lots of mix amended 1 day prior to seeding, but over 60% in lots of mix amended 6 days prior to seeding, compared to 43% in the infested control. With the exception of isolate G-65 in the lot amended 6 days before seeding, the isolates of T. virens were as effective as metalaxyl (19% damping-off) for control of P. ultimum in lots of mix amended 1 to 6 days before seeding. In contrast to T. virens, biocontrol efficacy of isolates BNR621 and P9023 of binucleate Rhizoctonia spp. in a Pesta formulation improved as lots of mix were amended up to 6 days before seeding and infestation. As length of initial amendment increased from 1 to 6 days, preemergence damping-off decreased from 37 to 16% for BNR621, and from 42 to 22% for P9023. Preemergence damping-off was observed in vinca in control treatments with only the putative biocontrol agents (BNR621, 14% disease and P9023, 19.6%); therefore, additional bedding plant species were evaluated for susceptibility to the BNR isolates. In the absence of P. ultimum, isolates BNR621 and P9023 in a Pesta formulation caused an average 82.5, 56.5, and 5.8% damping-off of snapdragon, petunia, and impatiens, respectively. Our results suggest that binucleate Rhizoctonia isolates, although effective for biocontrol of P. ultimum on vinca, should be evaluated for pathogenicity on a crop by crop basis before use on other crops. }, number={6}, journal={PLANT DISEASE}, author={Burns, JR and Benson, DM}, year={2000}, month={Jun}, pages={644–648} }
 @article{keinath_batson_caceres_elliott_sumner_brannen_rothrock_huber_benson_conway_et al._2000, title={Evaluation of biological and chemical seed treatments to improve stand of snap bean across the southern United States}, volume={19}, ISSN={["1873-6904"]}, DOI={10.1016/S0261-2194(00)00047-8}, abstractNote={Thirteen bacterial, four fungal, and four chemical fungicide seed treatments were evaluated one or more years in multiple field locations across the southern United States. Snap bean seed was treated in bulk with fungicides and most biocontrol agents, shipped to individual locations, and stored until planting or treated on site immediately before planting. Populations of biocontrol agents on seeds were assayed after seed treatment and planting. Analysis of variance of percent plant stand at 28 days after sowing revealed highly significant (P<0.01) effects of location and treatment in 1996, 1997 and 1998. A treatment by location interaction also occurred in 1996 and 1997. When treatments tested in two or three years were analyzed together, no biological seed treatments significantly affected percent stand. Carboxin significantly increased percent stand compared with nontreated seed in data sets combined from 1997 and 1998 and 1996 to 1998; captan and carboxin plus metalaxyl also increased stand in 1997 and 1998. Improvements in efficacy and consistency of biological seed treatments are necessary before they can be recommended for use in snap bean production.}, number={7}, journal={CROP PROTECTION}, author={Keinath, AP and Batson, WE and Caceres, J and Elliott, ML and Sumner, DR and Brannen, PM and Rothrock, CS and Huber, DM and Benson, DM and Conway, KE and et al.}, year={2000}, month={Aug}, pages={501–509} }
 @article{hinesley_parker_benson_2000, title={Evaluation of seedlings of Fraser momi, and Siberian fir for resistance to Phytophthora cinnamomi}, volume={35}, number={1}, journal={HortScience}, author={Hinesley, L. E. and Parker, K. C. and Benson, D. M.}, year={2000}, pages={87–88} }
 @article{benson_grand_2000, title={Incidence of Phytophthora root rot of Fraser fir in North Carolina and sensitivity of isolates of Phytophthora cinnamomi to metalaxyl}, volume={84}, ISSN={["0191-2917"]}, DOI={10.1094/pdis.2000.84.6.661}, abstractNote={ A survey of Fraser fir Christmas trees in North Carolina for incidence of Phytophthora root rot was conducted during 1997 and 1998. Field sites (7- to 13-year-old trees) and nursery transplant beds (4- to 5-year-old trees) selected at random were surveyed based on foliar symptoms of Phytophthora root rot. Field sites were surveyed with a random transect method (>3,000 trees/field) or by counting all trees (<3,000 trees/field). Overall, incidence of Phytophthora root rot averaged 9% over the 58 field sites sampled, with a range of 0 to 75%. No relationship was found between number of years Fraser fir had been planted in the field site and disease incidence. Disease incidence did not increase as field sites were rotated through second or third crops of Fraser fir. Phytophthora spp. were recovered from 1.8% of asymptomatic trees sampled from 58 field sites across the state. P. cinnamomi accounted for 91% of the Phytophthora isolates recovered. In nursery transplant beds where a systematic sampling procedure was used, incidence of diseased trees averaged 2%, with a range of 0 to 12% across 16 locations. Recovery of Phytophthora spp. averaged 1.2% from root samples collected from 50 asymptomatic seedlings at each location. Isolates collected from the field and nursery transplant beds were grown on cornmeal agar incorporated with 0, 1, 1.25, 10, or 100 μg a.i. metalaxyl/ml. All 166 isolates of P. cinnamomi tested were sensitive to metalaxyl at 1 or 1.25 μg a.i. metalaxyl/ml. Although incidence of Phytophthora root rot has not increased in the state compared to a survey done in 1976 to 1977, the disease continues to limit production of Fraser fir in North Carolina. }, number={6}, journal={PLANT DISEASE}, author={Benson, DM and Grand, LF}, year={2000}, month={Jun}, pages={661–664} }
 @article{benson_ranney_parker_1998, title={Evaluation of Photinia spp. For resistance to entomosporium leaf spot, 1996, 1997}, volume={13}, number={1998}, journal={Biological and Cultural Tests for Control of Plant Diseases}, author={Benson, D. M. and Ranney, T. G. and Parker, K. C.}, year={1998}, pages={68} }
 @article{benson_hinesley_frampton_parker_1997, title={Evaluation of six Abies spp. to Phytophthora root rot caused by Phytophthora cinnamomi}, volume={13}, journal={Biological and Cultural Tests for Control of Plant Diseases}, author={Benson, D. M. and Hinesley, L. E. and Frampton, J. and Parker, K. C.}, year={1997}, pages={57} }
 @article{benson_1995, title={Aluminum amendment of potting mixes for control of Phytophthora damping-off in bedding plants}, volume={30}, ISSN={["0018-5345"]}, DOI={10.21273/hortsci.30.7.1413}, abstractNote={Control of preemergence damping-off caused by Phytophthora parasitica Dastur was investigated on three bedding plant species in a 1 peat: 1 vermiculite medium (v/v) limed at 3 kg·m–3 and drenched with aluminum at 10, 25, or 50 meq Al/100 cm3 medium. Aluminum as Al2(SO4)3 was applied as a drench at 0.75, 1.9, or 3.75 g/150 ml water to the surface of infested medium in 650-cm2 plug trays (1300-cm3 tray volume). All concentrations of aluminum were effective in controlling preemergence damping-off of snapdragon (Antirrhinum majus L.) and vinca (Catharanthus roseus G. Don, Madagascar periwinkle), but only 50 meq Al+3/100 cm3 medium was effective for petunia (Petunia ×hybrida Hort. Vilm.-Andr.). At 4 days after seeding and drenching with aluminum sulfate, exchangeable aluminum was 0, 0.5, and 2.03 meq Al+3/100 g medium, respectively, for the three concentrations used. Control of damping-off of snapdragon and vinca with 10 meq Al+3/100 cm3 medium with no detectable exchangeable aluminum 4 days after application suggests that P. parasitica was suppressed by aluminum early in the host–pathogen interaction, whereas petunia was susceptible to damping-off for a longer period before seedling emergence. Aluminum was not phytotoxic to vinca, snapdragon, or petunia grown in a limed medium.}, number={7}, journal={HORTSCIENCE}, author={Benson, DM}, year={1995}, month={Dec}, pages={1413–1416} }
 @misc{cartwright_benson_1994, title={Pseudomonas cepacia strain 5.5B and method of controlling Rhizoctonia solani therewith}, volume={5288633}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Cartwright, D. K. and Benson, D. M.}, year={1994} }
 @article{benson_1993, title={Fungicides in poinsettia propagation}, volume={38}, number={1}, journal={North Carolina Flower Growers' Bulletin}, author={Benson, D. M.}, year={1993}, pages={1} }
 @article{benson_1993, title={SUPPRESSION OF PHYTOPHTHORA-PARASITICA ON CATHARANTHUS-ROSEUS WITH ALUMINUM}, volume={83}, ISSN={["0031-949X"]}, DOI={10.1094/Phyto-83-1303}, abstractNote={The relationship of exchangeable aluminum, liming rate, and control of preemergence damping-off of Catharanthus roseus caused by Phytophthora parasitica was investigated. A peat/vermiculite medium at pH 4.1 was limed at 0, 3, or 6 g of dolomitic limestone per 1,000 cm 3 of medium and misted for 3 days prior to seeding with Catharanthus roseus in 81-cell plug trays. Seeds were covered with additional medium infested with Phytophthora parasitica on colonized rice particles. Aluminum sulfate at rates of 17-250 meq of Al per 100 cm 3 of medium was drenched onto the surface of the medium. Samples were collected beginning 2 days after seeding to determine pH, exchangeable Al, and population density of P. parasitica [...]}, number={12}, journal={PHYTOPATHOLOGY}, author={BENSON, DM}, year={1993}, month={Dec}, pages={1303–1308} }
 @article{benson_1992, title={DETECTION BY ENZYME-LINKED-IMMUNOSORBENT-ASSAY OF RHIZOCTONIA SPECIES ON POINSETTIA STEM CUTTINGS}, volume={76}, ISSN={["0191-2917"]}, DOI={10.1094/PD-76-0578}, abstractNote={A multiwell enzyme-linked immunosorbent assay (ELISA) and rapid assay ELISA were evaluated for detection of binucleate and multinucleate isolates of Rhizoctonia spp. on poinsettia cuttings in propagation. Rice grain inoculum of each test isolate was positioned 2 cm on either side of the cutting. At 2, 3, and 7 days, poinsettia stem samples were rated visually for Rhizoctonia stem rot and then split in half for ELISA or for culture on acidified potato-dextrose agar (.)}, number={6}, journal={PLANT DISEASE}, author={BENSON, DM}, year={1992}, month={Jun}, pages={578–581} }
 @article{benson_1992, title={FUNGICIDES AS FOLIAR SPRAYS OR ROOTING CUBE SOAKS IN PROPAGATION OF POINSETTIA}, volume={27}, ISSN={["0018-5345"]}, DOI={10.21273/hortsci.27.9.1006}, abstractNote={Several fungicides, including benomyl, flutolanil, iprodione, metalaxyl, and a mixture of metalaxyl and benomyl that control rhizoctonia stem rot (Rhizoctonia solani Kuhn) of poinsettia (Euphorbia pulcherriman Willd. ex Kl.) were evaluated for inhibition of poinsettia root initials and suppression of root elongation. Fungicides were applied as either foliar sprays to poinsettia cuttings in rooting cubes or as soaks of rooting cubes before sticking of cuttings. Rooting cube soaks of iprodione and benomyl and fungicide sprays of iprodione, benomyl, and chlorothalonil inhibited root initiation as measured by root counts 28 days after sticking cuttings. However, root elongation as measured by root rating was similar for all fungicides and the untreated control at 28 days. Plant height of rooted poinsettia cuttings transplanted to 400-cm3 pots was significantly less (P = 0.05) only for cuttings sprayed initially with iprodione, but not for rooting cubes soaked in iprodione 58 days after transplanting. The inhibitory effect of other fungicides on root initiation did not appear to affect plant growth once plants were transplanted. Chemical names used: methyl 1-(butyl-carbamoyl)-2-benzimidazolecarbamate (benomyl); tetrachloroisophthalonitrile (chlorothalonil); N -[3-(methylethoxy)phenyl]-2-(trifluoromethyl)benzamide (flutolanil); 3-(3,5dichlorophenyl)N -(lmethylethyl)-2,4-dioxo-l-imidazolidinecarboxamide (iprodione); N -(2,6-dimethylphyenyl)N -(methoxyacetyl) alanine methyl ester (metalaxyl).}, number={9}, journal={HORTSCIENCE}, author={BENSON, DM}, year={1992}, month={Sep}, pages={1006–1008} }
 @article{benson_1991, title={CONTROL OF RHIZOCTONIA STEM ROT OF POINSETTIA DURING PROPAGATION WITH FUNGICIDES THAT PREVENT COLONIZATION OF ROOTING CUBES BY RHIZOCTONIA-SOLANI}, volume={75}, ISSN={["0191-2917"]}, DOI={10.1094/PD-75-0394}, abstractNote={The effectiveness of several fungicides applied either as foliar sprays or as rooting-cube soaks was compared for control of Rhizoctonia stem rot of poinsettia during propagation. Rhizoctonia solani was introduced to the surface of rigid foam rooting cubes at the time cuttings were stuck. Benomyl at 0.3 g a.i./L, chlorothalonil at 1.8 ml a.i./L, flutolanil at 0.3 g a.i./L, iprodione at 0.6 g a.i./L, and metalaxyl + benomyl at 0.5 g a.i./L all prevented stem rot. Rooting-cube soaks of flutolanil, iprodione, and metalaxyl + benomyl were as effective as foliar sprays in disease control. Foliar sprays of quintozene at 0.45 g a.i./L and ethazole + thiophanate methyl at 0.24 g a.i./L were not as effective in control of stem rot as the other fungicides tested (.)}, number={4}, journal={PLANT DISEASE}, author={BENSON, DM}, year={1991}, month={Apr}, pages={394–398} }
 @article{benson_1991, title={DETECTION OF PHYTOPHTHORA-CINNAMOMI IN AZALEA WITH COMMERCIAL SEROLOGICAL ASSAY KITS}, volume={75}, ISSN={["0191-2917"]}, DOI={10.1094/PD-75-0478}, abstractNote={Two commercial serological assay kits were compared to a culture plate method for detection of Phytophthora cinnamomi in root samples from inoculated azaleas. Both the multiwell E kit and the rapid assay F kit detected P. cinnamomi on azalea roots beginning 1 wk after inoculation. Agreement between immunoassay kits and culture plate results for detection of P. cinnamomi was most consistent beginning 3−5 wk after inoculation. Root symptoms, but not foliar symptoms, of Phytophthora root rot were evident during this period. There was a positive correlation between root rot severity in greenhouse trials and root sample absorbance (multiwell) or meter reading (rapid assay) but not between symptom severity and immunoassay results (.)}, number={5}, journal={PLANT DISEASE}, author={BENSON, DM}, year={1991}, month={May}, pages={478–482} }
 @article{benson_fantz_skroch_1990, title={'Fred Cochran' Carla azalea}, volume={25}, number={4}, journal={HortScience}, author={Benson, D. M. and Fantz, P. R. and Skroch, W. A.}, year={1990}, pages={490} }
 @article{benson_1990, title={Fungicides for control of Rhizoctonia stem rot of poinsettia in oasis rooting cubes}, volume={35}, number={3}, journal={North Carolina Flower Growers' Bulletin}, author={Benson, D. M.}, year={1990}, pages={6} }
 @article{benson_1990, title={LANDSCAPE SURVIVAL OF FUNGICIDE-TREATED AZALEAS INOCULATED WITH PHYTOPHTHORA-CINNAMOMI}, volume={74}, ISSN={["1943-7692"]}, DOI={10.1094/PD-74-0635}, abstractNote={Containerized Hinodegiri azalea in a pine bark:sand medium were inoculated with oat grains colonized by Phytophthora cinnamomi. Plants were treated with three foliar sprays of fosetyl-Al (4.79 g a.i./L), with two drenches of metalaxyl (0.078 ml a.i./L), or left untreated over the next 61 days before being transplanted to pathogen-free landscape beds (.)}, number={9}, journal={PLANT DISEASE}, author={BENSON, DM}, year={1990}, month={Sep}, pages={635–637} }
 @article{benson_blazich_1989, title={Control of Phytophthora root rot of Rhododendron chapmanii A. Gray with Subdue}, volume={7}, number={2}, journal={Journal of Environmental Horticulture}, author={Benson, D. M. and Blazich, F. A.}, year={1989}, pages={73} }
 @article{reynolds_gold_bruck_benson_campbell_1986, title={SIMULATION OF THE SPREAD OF PHYTOPHTHORA-CINNAMOMI CAUSING A ROOT-ROT OF FRASER FIR IN NURSERY BEDS}, volume={76}, ISSN={["1943-7684"]}, DOI={10.1094/Phyto-76-1190}, number={11}, journal={PHYTOPATHOLOGY}, author={REYNOLDS, KM and GOLD, HJ and BRUCK, RI and BENSON, DM and CAMPBELL, CL}, year={1986}, month={Nov}, pages={1190–1201} }
 @article{reynolds_benson_bruck_1985, title={EPIDEMIOLOGY OF PHYTOPHTHORA ROOT-ROT OF FRASER FIR - ESTIMATES OF RHIZOSPHERE WIDTH AND INOCULUM EFFICIENCY}, volume={75}, ISSN={["1943-7684"]}, DOI={10.1094/Phyto-75-1010}, number={9}, journal={PHYTOPATHOLOGY}, author={REYNOLDS, KM and BENSON, DM and BRUCK, RI}, year={1985}, pages={1010–1014} }
 @article{reynolds_benson_bruck_1985, title={EPIDEMIOLOGY OF PHYTOPHTHORA ROOT-ROT OF FRASER FIR - ROOT COLONIZATION AND INOCULUM PRODUCTION}, volume={75}, ISSN={["1943-7684"]}, DOI={10.1094/Phyto-75-1004}, number={9}, journal={PHYTOPATHOLOGY}, author={REYNOLDS, KM and BENSON, DM and BRUCK, RI}, year={1985}, pages={1004–1009} }
 @article{benson_1984, title={New fungicides offer protection against phytophthora root rot}, volume={159}, number={2}, journal={American Nurseryman}, author={Benson, D. M.}, year={1984}, pages={101} }
 @article{fravel_benson_bruck_1983, title={EDAPHIC PARAMETERS ASSOCIATED WITH SHORE JUNIPER DECLINE}, volume={73}, ISSN={["1943-7684"]}, DOI={10.1094/Phyto-73-204}, abstractNote={Fravel, D. R., Benson, D. M., and Bruck, R. I. 1983. Edaphic parameters associated with shore juniper decline. Phytopathology 73:204-207. In the absence of evidence of a biotic agent as the primary cause of decline parameters of the A+B horizon were better indicators of decline than those of shore juniper (Juniperus conferta), abiotic factors were examined to of the C horizon. Supportive evidence for the involvement of these determine their roles in contributing to decline. Six of 20 edaphic components was provided by tissue nutrient analysis from landscape components measured in 20 landscape plantings were significantly plantings and from greenhouse studies of nutrient deficiencies and water interrelated to decline index in a multivariate principal axis factor analysis. stress in which nitrogen deficiency and, in one case, both water excesses and These parameters were calcium, clay + silt content, magnesium, nitrate, deficiencies, induced symptoms resembling decline. phosphorus, and zinc. Where soil horizons could be distinguished, Additional key words: abiotic stress. Shore juniper, Juniperus conferta Parl., is a low-growing shrub SJD, investigations were undertaken to examine abiotic agents as that has increased in popularity as a landscape plant in North causes of or factors contributing to SJD. The sensitivity of shore Carolina during the past several years. The numbers of shore juniper to low dosages of ozone, alone and in combination with juniper specimens submitted to the North Carolina Plant Disease NO 2 and SO 2, has been reported elsewhere (4). The roles of certain and Insect Clinic also increased during this period. Many of these edaphic components in SJD are discussed in this article. plants showed symptoms of a previously undescribed decline. Symptoms of decline included chlorosis of the older needles that MATERIALS AND METHODS progresses to necrosis, beginning at the soil line and advancing up Edaphic components study. Twenty landscape plantings of shore the plant stem. Stunting, root necrosis, and small, tan foliar lesions juniper representing different severity levels of SJD were selected in were observed less frequently. Research was undertaken to Wake County, NC. Plantings had been in place a minimum of 3 yr. determine the etiology of shore juniper decline (SJD). At each site, 20 plants, approximately one plant per square meter, A root and crown rot, wilting, stunting, and death were reported were rated for SJD as follows: I = no symptoms, 2 = chlorosis on to be caused by either Phytophthora cinnamomi Rands, P. the basal third of the plant, 3 = chlorosis and some necrosis on the nicotianae Dast. var. nicotianae (Breda de Haan) Tucker, Pythium basal third, 4 = lower third of plant necrotic, 5 = lower third of irregulare Buisman, or P. sylvalicum Campbell & Hendrix (7). In plant necrotic and chlorosis of the middle third, 6 = basal third repeated, replicated greenhouse experiments, inoculation of 1-yrnecrotic and some necrosis of the middle third, 7 = basal two-thirds old plants with P. cinnamomi-infested oat grains produced necrotic, 8 = lower two-thirds necrotic and chlorosis of the top symptoms resembling those of decline after 6-8 wk (4,5). Plant size third, 9 = lower two-thirds of plant necrotic and some necrosis of indices and root and shoot fresh weights were also significantly the upper third, and 10 = plant dead. smaller in P. cinnamomi-inoculated plants than in those inoculated Approximately 500 cm' each of surface soil (A+B horizons) and with sterile oat grains or not inoculated. Because root necrosis is subsoil (C horizon) were collected at each site. Where soil was generally assotiated with P. cinnamomi infection but not with homogeneous to a depth of 30 cm, only one sample was taken. SJD, P. cinnamomi was not considered a primary cause of SJD. When the C horizon was encountered in the first 30 cm, A+B and C A binucleate, Rhizoctonialike fungus was consistently recovered horizons were collected separately. Depth of the A+B horizon was from surface-disinfested needles of shore juniper. Inoculations of recorded. Soil color was determined by the Munsell soil color book shore juniper with 13 of these isolates under conditions of several (Munsell Products, Baltimore, MD 21233). Color code letters were variations of relative humidity, host water potential, inoculum converted to numeric values as follows: 1 = 1 YR, 2 = 2.5 YR, 3 = 4 placement, wounding, and inoculum substrate failed to produce YR, 5 = 7.5 YR, and 6 = 10 YR. Thus, the higher numbers indicate decline symptoms (4). Inoculations with eight other fungi, as well as decreasing soil redness. Soil mottles were rated by the following naturally infested debris, also failed to induce decline symptoms scale: 0 = none, I = few, 2 = moderate, 3 = abundant, and 4 = (4). Populations of plant parasitic nematodes at decline sites were numerous. The proportion of sand and clay + silt was determined considered too low to be a probable contributing factor in SJD (4; by wet sieving 10 g of soil (oven dry weight, 60 C for 24 hr). Sand D. M. Benson, unpublished), retained by a sieve with a 53-jim opening was collected, oven-dried In the absence of a detectable biotic agent as the primary cause of 24 hr at 60 C, and weighed. The proportion of clay + silt was determined by subtraction. Acidity, pH, cation exchange capacity, The publication costs of this article were defrayed in part by page charge payment. This base saturation, percent organic matter, and weight per volume article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. § bulk s ity) were de term by t g ic DivonNot 1734 solely to indicate this fact. (bulk density) were determined by the Agronomic Division, North Carolina Department of Agriculture (NCDA). Exchangeable and ©1983 The American Phytopathological Society extractable anions and cations (calcium, copper, magnesium,}, number={2}, journal={PHYTOPATHOLOGY}, author={FRAVEL, DR and BENSON, DM and BRUCK, RI}, year={1983}, pages={204–207} }
 @article{benson_shew_jones_1982, title={Effect of raised and ground-level beds and pine bark on survival of azalea and population dynamics of Phytophthora cinnamomi}, volume={4}, DOI={10.1080/07060668209501298}, number={3}, journal={Canadian Journal of Plant Pathology}, author={Benson, D. M. and Shew, H. D. and Jones, R. K.}, year={1982}, pages={278} }
 @article{benson_cochran_1980, title={Resistance of evergreen hybrid azaleas to root rot caused by Phytophthora cinnamomi}, volume={64}, number={2}, journal={Plant Disease}, author={Benson, D. M. and Cochran, F. D.}, year={1980}, pages={214} }
 @article{benson_barker_1978, title={Aldicarb and 1,2-dibromo-3-chloropropane as postplant treatments for control of nematodes on American boxwood, and Japanese and Chinese hollies}, volume={62}, number={3}, journal={Plant Disease Reporter}, author={Benson, D. M. and Barker, K. R.}, year={1978}, pages={209} }
 @article{benson_jones_daughtry_1978, title={Ground covers that restrict disease spread}, volume={148}, number={4}, journal={American Nurseryman}, author={Benson, D. M. and Jones, R. K. and Daughtry, B. I.}, year={1978}, pages={19} }
 @article{reynolds_bruck_benson, title={The epidemiology of Phytophthora root rot of Fraser fir. II. Zoospore movement}, volume={75}, journal={Phytopathology}, author={Reynolds, K. M. and Bruck, R. I. and Benson, D. M.}, pages={1010–1014} }