Detection of Pythium spp. in golf course irrigation systems

Plant Disease ◽  
2021 ◽  
Author(s):  
Clayton A Rushford ◽  
Rebecca L North ◽  
Gerald Leo Miller
Keyword(s):  
Phylogenetic Trees ◽  
Membrane Filtration ◽  
Sampling Site ◽  
Creeping Bentgrass ◽  
Water Sources ◽  
Crown Rot ◽  
Golf Course ◽  
Nutrient Concentrations ◽  
Pythium Species ◽  
Irrigation Systems

Many Pythium spp. are causal agents of diseases of turfgrasses. Pythium spp. disseminate through irrigation systems in agricultural settings, and this study provides evidence that Pythium spp. also disseminate through golf course irrigation. Water samples were collected from irrigation heads and water sources at ten golf courses in Missouri and Kansas. Samples were collected from 2018 to 2019 in April, July, and October. Phosphorus, nitrogen, and chloride concentrations were measured from irrigation head samples to determine if these parameters influence frequency of Pythium spp. detected. Pythium spp. were detected in samples through baiting and membrane filtration. Cultures were isolated on PARP media and DNA was extracted from putative Pythium isolates. The ITS region was PCR amplified and sequenced. Phylogenetic trees were constructed using representative sample sequences, sequences from seven morphologically identified reference isolates of Pythium, and similar Genbank accessions. Detected Oomycete species include Lagenidium giganteum, Pythium biforme, P. insidiosum, P. marsipium, P. plurisporium, and Saprolegnia hypogyna. Twenty-one clades lacked species-level resolution, and fourteen of these clades were associated with Pythium species. Clades A, C, D, E, I, and M contain Pythium species that cause root and crown rot on creeping bentgrass. Detected Pythium communities were dependent on the detection method used and sampling source. Pythium frequency and diversity were highest in April 2019. Sample temperature, sampling site, chloride, and nutrient concentrations did not influence Pythium frequency in samples. Irrigation systems using surface water sources contained at least three Pythium spp. over the course of two years.

Loading rates of nutrients discharging from a golf course and a neighboring forested basin

1999 ◽  
Vol 39 (12) ◽  
pp. 99-107 ◽  
Author(s):  
Takao Kunimatsu ◽  
Miki Sudo ◽  
Takeshi Kawachi
Keyword(s):  
Nutrient Loading ◽  
Chamaecyparis Obtusa ◽  
Phosphorus Loading ◽  
Golf Course ◽  
Nutrient Concentrations ◽  
Golf Courses ◽  
Japanese Cypress ◽  
Arithmetic Average ◽  
Loading Rates ◽  
Runoff Rate

In the last ten years, the number of golf courses has been increasing in some countries as the game gains popularity. This indicates, a need to estimate the nutrient loading from golf courses in order to prevent the eutrophication of water bodies. Nutrient concentrations and flow rates of a brook were measured once a week from 1989 to 1990 at two sites: Site A of a brook flowing out from D-golf course (53 ha) and Site B of the same brook discharging into the golf course from an upper forested basin (23 ha) covered mainly with planted Japanese cypress (Chamaecyparis obtusa SIEB. et ZUCC). The bedrock of the area was granite. The annual values of precipitation and mean temperature were 1947 mm and 13.5°C in 1989, respectively. The arithmetic average values of discharge from the forested basin and the golf course were 0.392 and 1.26 mg/l total nitrogen (TN), 0.0072 and 0.145 mg/l total phosphorus (TP), 0.82 and 3.53 mg/l potassium ion (K+, 5.92 and 8.24 mg/l sodium ion (Na+), 2.1 and 9.9 mg/l suspending solid (0.001–2.0 mm, SS), 0.087 and 0.147 mS/cm electric conductivity (EC), and 0.031 and 0.037 m3/km2•s specific discharge, respectively. The loading rates of the forested basin and the golf course were 5.42 and 13.5 TN, 0.133 and 3.04 TP, 8.84 and 33.9 K+, 55.0 and 73.0 Na+, and 54.3 and 118 SS in kg/ha•y. The leaching and runoff rate of nitrogen in the chemical fertilizers applied on the golf course was calculated as 32%. These results indicated the importance of controlling the phosphorus loading for the management of golf courses.

scholarly journals Influence of Ozone Treatment on Ultrafiltration Performance and Nutrient Flow in a Membrane Based Nutrient Recovery Process from Anaerobic Digestate

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 64 ◽  
Author(s):  
Tobias Gienau ◽  
Artjom Ehrmanntraut ◽  
Matthias Kraume ◽  
Sandra Rosenberger
Keyword(s):  
Membrane Filtration ◽  
Recovery Process ◽  
Ozone Treatment ◽  
Organic N ◽  
Nutrient Concentrations ◽  
Particle Removal ◽  
Process Chain ◽  
K Fertilizer ◽  
P Fertilizer ◽  
Biogas Plants

Membrane filtration of biological suspensions is frequently limited by fouling. This mechanism is well understood for ultrafiltration of activated sludge in membrane bioreactors. A rather young application of ultrafiltration is the recovery of nutrients from anaerobic digestates, e.g., from agricultural biogas plants. A process chain of solid/liquid separation, ultrafiltration, and reverse osmoses separates the digestate into different products: an organic N-P-fertilizer (solid digestate), a recirculate (UF retentate), a liquid N-K-fertilizer (RO retentate) and water. Despite the preceding particle removal, high crossflow velocities are required in the ultrafiltration step to overcome fouling. This leads to high operation costs of the ultrafiltration step and often limits the economical application of the complete process chain. In this study, under-stoichiometric ozone treatment of the ultrafiltration feed stream is investigated. Ozone treatment reduced the biopolymer concentration and apparent viscosity of different digestate centrates. Permeabilities of centrate treated with ozone were higher than without ozone treatment. In a laboratory test rig and in a pilot plant operated at the site of two full scale biogas plants, ultrafiltration flux could be improved by 50–80% by ozonation. Nutrient concentrations in the fertilizer products were not affected by ozone treatment.

scholarly journals Residual Efficacy of Fungicides for Control of Dollar Spot on Creeping Bentgrass

Plant Disease ◽  
2006 ◽  
Vol 90 (5) ◽  
pp. 571-575 ◽  
Author(s):  
Richard Latin
Keyword(s):  
Creeping Bentgrass ◽  
Effective Concentration ◽  
Disease Suppression ◽  
Golf Course ◽  
Sclerotinia Homoeocarpa ◽  
Dollar Spot ◽  
Residual Efficacy ◽  
Bioassay Technique ◽  
Precipitous Decline ◽  
Field Plots

The duration of effective concentrations of fungicides for control of dollar spot on creeping bentgrass fairways was investigated using a bioassay technique. In each of three runs of the experiment, fungicide treatments were applied once to turf in replicated field plots; then, the plots were sampled periodically over 3 weeks by removing turf plugs from the field. The sampled plugs were placed in incubation containers and inoculated with sections from a 4-day-old colony of Sclerotinia homoeocarpa growing on potato dextrose agar. After a 96-h incubation period, the extent of pathogen growth on the turf plugs was measured. Results described a precipitous decline in effective concentration for all fungicide treatments beginning 7 to 10 days after application. The fungicides were only marginally effective at 14 days after application, and none provided any disease suppression at 21 days after application. The efficacy half-life (EHL) associated with four of the fungicides (chlorothalonil, iprodione, propiconazole, and thiophanate methyl) was estimated with two models. EHL estimates ranged from 6.1 to 15.2 days depending on the fungicide and the model. This research contributes to our knowledge of the duration of effective fungicide concentrations on creeping bentgrass and can provide insight for scheduling fungicide sprays for golf course fairways.

scholarly journals Mowing Frequency and Plant Growth Regulator Effects on Dollar Spot Severity and on Duration of Dollar Spot Control by Fungicides

Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1433-1442 ◽  
Author(s):  
Alexander I. Putman ◽  
John E. Kaminski
Keyword(s):  
Plant Growth ◽  
Creeping Bentgrass ◽  
Agrostis Stolonifera ◽  
Golf Course ◽  
Sclerotinia Homoeocarpa ◽  
Dollar Spot ◽  
Confounding Effect ◽  
Residual Efficacy ◽  
The University ◽  
University Of Connecticut

Management of dollar spot (incited by Sclerotinia homoeocarpa) on golf course fairways is increasingly challenging. The objectives of this study were to determine the influence of mowing frequency and plant growth regulators (PGRs) on dollar spot severity and on the residual efficacy of fungicides for control of dollar spot. Two 4-month-long studies were conducted on ‘Putter’ creeping bentgrass (Agrostis stolonifera) maintained as a fairway at the University of Connecticut. Treatments were arranged in a three-by-three-by-five factorial that assessed the influence of mowing frequency (2, 4, or 6 days week–1) and PGRs (paclobutrazol, trinexapac-ethyl, or none) on dollar spot control by five fungicide treatments (boscalid, chlorothalonil, iprodione, propiconazole, or none). Turf was mowed in the afternoon hours to minimize the confounding effect of mowing frequency on leaf wetness duration. Treatments were initiated in the late spring of 2007 and 2008, and each fungicide treatment was reapplied only when dollar spot exceeded a threshold of five infection centers plot–1. In the absence of fungicides, dollar spot severity was reduced by 63 to 90% in plots treated with paclobutrazol and by 13 to 55% in plots treated with trinexapac-ethyl. Dollar spot severity was 23 to 50% lower in plots mown 2 days week–1 compared with those mown 6 days week–1. In cases where a significant interaction was observed between mowing frequency and PGRs, dollar spot was reduced on most rating dates in plots treated with trinexapacethyl that were mown 2 days week–1 compared with those mown 6 days week–1. Survival analysis of days until threshold was met revealed that duration of control of fungicides in plots receiving paclobutrazol were 28 to 84% longer compared with plots not receiving PGR. Duration of control by fungicides was generally similar between plots treated with trinexapac-ethyl and no PGR. In general, mowing frequency did not influence duration of control. Results from this study indicate that paclobutrazol could be used to increase the treatment interval of fungicides and that mowing frequency in the absence of dew is likely to have little influence on fungicide residual efficacy. When used without fungicides, PGRs and less frequent mowing may reduce dollar spot in situations where fungicide use is limited.

scholarly journals Pythium Species Associated with Root Dysfunction of Creeping Bentgrass in Maryland

Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 516-520 ◽  
Author(s):  
Yan Feng ◽  
Peter H. Dernoeden
Keyword(s):  
Creeping Bentgrass ◽  
Golf Courses ◽  
Agrostis Palustris ◽  
Pythium Species ◽  
Annual Bluegrass ◽  
Large Numbers ◽  
Putting Green ◽  
Pathogenicity Tests ◽  
Cornmeal Agar ◽  
Isolated Species

Putting green samples (n = 109) were inspected for the presence of Pythium oospores in roots of plants from golf courses (n = 39) in Maryland and adjacent states. Twenty-eight Pythium isolates were recovered from creeping bentgrass (Agrostis palustris) (n = 25) and annual bluegrass (Poa annua) (n = 3) plants. Most isolates associated with Pythium-induced root dysfunction were from greens less than 3 years of age and were obtained primarily between March and June, 1995 to 1997. Eight Pythium species (P. aristosporum, P. aphanidermatum, P. catenulatum, P. graminicola, P. torulosum, P. vanterpoolii, P. volutum, and P. ultimum var. ultimum) were isolated from creeping bentgrass and two species (P. graminicola and P. torulosum) were from annual bluegrass. All species, except P. catenulatum, were pathogenic to ‘Crenshaw’ creeping bentgrass seedlings in postemergence pathogenicity tests. P. aristosporum (n = 3) and P. aphanidermatum (n = 1) were highly aggressive at a low (18°C) and a high temperature (28°C). P. graminicola (n = 1) was low to moderately aggressive. P. torulosum (n = 12) was the most frequently isolated species, but most isolates were either nonpathogenic or caused very little disease. P. aristosporum (n = 3) and P. aphanidermatum (n = 1) were highly aggressive and were associated with rapid growth at 18 and 28°C on cornmeal agar. P. volutum (n = 1) was highly aggressive at 18°C, but was one of slowest growing isolates. Infected roots were generally symptomless, and the number of oospores observed in roots was not always a good indicator of disease or of the aggressiveness of an isolate. Large numbers of oospores of low or even nonpathogenic species may cause dysfunction of creeping bentgrass roots.

scholarly journals Selective removal of cationic micro-pollutants using disulfide-linked network structures

RSC Advances ◽  
2017 ◽  
Vol 7 (42) ◽  
pp. 25969-25977 ◽  
Author(s):  
Mehmet Sahin Atas ◽  
Sami Dursun ◽  
Hasan Akyildiz ◽  
Murat Citir ◽  
Cafer T. Yavuz ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Water Sources ◽  
Selective Removal ◽  
Network Structures ◽  
Organic Polymers ◽  
Great Affinity ◽  
Micro Pollutants

Micropollutants are found in all water sources, even after thorough treatments that include membrane filtration. We have developed swellable di-sulfide covalent organic polymers (COPs) with great affinity towards cationic textile micropollutants.

scholarly journals Occurrence and Molecular Identification of Azoxystrobin-Resistant Colletotrichum cereale Isolates from Golf Course Putting Greens in the Southern United States

Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 751-757 ◽  
Author(s):  
Joseph R. Young ◽  
Maria Tomaso-Peterson ◽  
Lane P. Tredway ◽  
Karla de la Cerda
Keyword(s):  
United States ◽  
Creeping Bentgrass ◽  
Amino Acid Sequences ◽  
Golf Course ◽  
Southern United States ◽  
Common Disease ◽  
Putting Greens ◽  
Qoi Fungicides ◽  
Colletotrichum Cereale

Turfgrass anthracnose, caused by Colletotrichum cereale (≡C. graminicola), has become a common disease of creeping bentgrass and annual bluegrass putting greens throughout the southern United States. Strobilurin (QoI) fungicides such as azoxystrobin are single-site mode-of-action fungicides applied to control C. cereale. In vitro bioassays with azoxystrobin at 0.031 and 8 μg/ml incorporated into agar were performed to evaluate the sensitivity of 175 isolates collected from symptomatic turfgrasses in Alabama, Mississippi, North Carolina, Tennessee, and Virginia. Three sensitivity levels were identified among C. cereale isolates. Resistant, intermediately resistant, and sensitive isolates were characterized by percent relative growth based on the controls with means of 81, 23, and 4%, respectively, on media containing azoxystrobin at 8 μg/ml. The molecular mechanism of resistance was determined by comparing amino acid sequences of the cytochrome b protein. Compared with sensitive isolates, C. cereale isolates exhibiting QoI resistance had a G143A substitution, whereas isolates expressing intermediate resistance had a F129L substitution. C. cereale isolates displaying azoxystrobin resistance in vitro were not controlled by QoI fungicides in a field evaluation. The dominance of QoI-resistant C. cereale isolates identified in this study indicates a shift to resistant populations on highly managed golf course putting greens.

scholarly journals Predicting the occurrence of stoneflies (Plecoptera) on the basis of water characteristics, river morphology and land use

2013 ◽  
Vol 16 (4) ◽  
pp. 812-821 ◽  
Author(s):  
Koen Lock ◽  
Peter L. M. Goethals
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Sampling Site ◽  
Environmental Parameters ◽  
Nutrient Concentrations ◽  
Support Vector ◽  
River Morphology ◽  
The European Union ◽  
Water Characteristics ◽  
Modelling Techniques

Stoneflies are macro-invertebrates that are sensitive water quality indicators. Here, their occurrence was modelled based on physical–chemical water characteristics, river morphology and land use with five different modelling techniques. In a case-study in Flanders, stoneflies were found in 219 samples and two sets of absence data were gathered: 219 random samples from sites without stoneflies and 219 samples from sites downstream of each sampling site where stoneflies were observed. With both random and downstream absences, logistic regressions, artificial neural networks, support vector machines, random forests and classification trees could all successfully predict stonefly occurrence. For most environmental parameters, significant differences were found between sites with and without stoneflies. As stoneflies were only detected in a few percent of the samples, the ecological water quality is obviously still too low in most watercourses. Based on planned water quality improvement measures, an ensemble forecast using the five mentioned modelling techniques predicted that stonefly prevalence will only increase marginally by 2015 and 2027. To meet the European Union Water Framework Directive requirements, which states that all surface waters should obtain a good ecological quality, a more ambitious management plan is needed to decrease nutrient concentrations and improve habitat quality.

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