Efficacy of Selected Insecticides in Reducing Rhodesgrass Mealybug (Hemiptera: Pseudococcidae) Density on Golf Course Putting Greens

In the fall of 2006, a golf course in Snoqualmie, WA renovated five putting greens with commercially produced Poa annua L. sod from British Columbia, Canada. Prior to the renovation, the greens had been planted with Agrostis stolonifera L. cv. Providence, which was removed during the renovation. In February of 2007, chlorotic patches were observed on the newly established P. annua greens. When the roots were examined, extensive galling was observed throughout plant roots. Galls were slender and twisted in appearance and less than one millimeter long. Upon dissection of washed galls, hundreds of eggs were exuded into the surrounding water droplet and both mature male and female nematodes were observed. Further morphometric examination of males, females, and juvenile nematodes demonstrated that they were Subanguina radicicola (Greef 1872) Paramanov 1967 (1). Amplification of nematode 18S, ITS1, and 5.8S regions, using previously published primers (2), resulted in a 100% sequence match with the publicly available sequence for S. radicicola, GenBank Accession No. AF396366. Each P. annua plant had an average of six galls (with a range of 1 to 8), primarily located within the top 2 cm of the soil. All five new P. annua putting greens at the golf course were infested with the nematode. Additionally, P. annua from two A. stolonifera cv. Providence greens that had not been renovated was infected, suggesting that the population occurred onsite and was not imported from the Canadian sod. S. radicicola has been identified as causing severe damage in New Brunswick, Canada on P. annua putting greens and in wild P. annua in the northwestern United States, but to our knowledge, this is the first report of the nematode affecting P. annua on a golf course in the United States. References: (1) E. L. Krall. Wheat and grass nematodes: Anguina, Subanguina, and related genera. Pages 721–760 in: Manual of Agricultural Nematology. Marcel Dekker, New York, 1991. (2) N. A. Mitkowski et al. Plant Dis. 86:840, 2002.

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Divergence in Life-History and Developmental Traits in Silvery-Thread Moss (Bryum argenteum Hedw.) Genotypes between Golf Course Putting Greens and Native Habitats

Weed Science ◽

10.1017/wsc.2018.37 ◽

2018 ◽

Vol 66 (5) ◽

pp. 642-650 ◽

Cited By ~ 2

Author(s):

Zane Raudenbush ◽

Joshua L. Greenwood ◽

D. Nicholas McLetchie ◽

Sarah M. Eppley ◽

Steven J. Keeley ◽

...

Keyword(s):

Life History ◽

Chlorophyll Content ◽

Common Garden ◽

Genotypic Diversity ◽

Inorganic Nutrients ◽

Golf Course ◽

Putting Greens ◽

Bryum Argenteum ◽

Putting Green ◽

Native Habitats

AbstractSilvery-Thread Moss (Bryum argenteum Hedw.) is an undesirable invader of golf course putting greens across North America, establishing colonies and proliferating despite practices to suppress it. The goal was to grow genotypes of green (growing in putting greens) and native (growing in habitats outside of putting greens) B. argenteum in a common garden experiment, allowing an experimental test of life-history traits between genotypes from these two habitats. Seventeen collections of green and 17 collections of native B. argenteum were cloned to single genotypes and raised through a minimum of two asexual generations in the lab. A culture of each genotype was initiated using a single detached shoot apex and was allowed to grow for 6 mo under conditions of inorganic nutrients present and absent. Compared with genotypes from native habitats, genotypes of B. argenteum from putting greens exhibited earlier shoot regeneration and shoot induction, faster protonemal extension, longer (higher) shoots, lower production of gemmae and bulbils, and greater aerial rhizoid cover, and showed similar tendencies of chlorophyll fluorescence properties and chlorophyll content. Cultures receiving no inorganic nutrients produced less chlorophyll content, greatly reduced growth, and bleaching of shoots. Mosses from putting greens establish more quickly, grow faster, produce more abundant rhizoids, and yet do not produce as many specialized asexual propagules compared with mosses of the same species from native habitats. The highly managed putting green environment has either selected for a suite of traits that allow the moss to effectively compete with grasses, or genotypic diversity is very high in this species, allowing a set of specialized genotypes to colonize the putting green from native habitats. Successful golf course weeds have been able to adapt to this highly competitive environment by selection acting on traits or genotypes to produce plants more successful in competing with golf course grasses.

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Occurrence and Distribution of QoI-Resistant Isolates of Colletotrichum cereale from Annual Bluegrass in California

Plant Disease ◽

10.1094/pdis-91-12-1536 ◽

2007 ◽

Vol 91 (12) ◽

pp. 1536-1546 ◽

Cited By ~ 21

Author(s):

Francis P. Wong ◽

Sharon L. Midland ◽

Karla A. de la Cerda

Keyword(s):

Golf Course ◽

Golf Courses ◽

Colletotrichum Graminicola ◽

Putting Greens ◽

Qoi Fungicides ◽

Mitochondrial Cytochrome B ◽

Colletotrichum Cereale ◽

Important Disease ◽

Qoi Resistance

Turfgrass anthracnose, caused by Colletotrichum cereale (ex. Colletotrichum graminicola), is an important disease of turf used on golf course putting greens. Recent management of the disease has become increasingly difficult, partly due to the possible development of practical resistance to the QoI fungicides. In all, 558 single-conidia isolates of C. cereale were collected from 10 California golf courses, 8 of which had been exposed to QoI fungicides and 2 where no fungicides had been used. Isolates were tested using a mycelial expansion assay on azoxystrobinamended media. For the two nonexposed populations, in vitro 50% effective dose (ED50) values ranged from 0.0060 to 0.089 μg/ml. All isolates from the exposed populations could not be fully inhibited by doses of azoxystrobin as high as 8.0 μg/ml. A subset of these isolates were tested in vitro with the QoI fungicides pyraclostrobin and trifloxystrobin and found to be similar in response, indicating that these isolates were fully cross-resistant to all three fungicides. In greenhouse pot experiments, three isolates nonresponsive to QoI fungicides in vitro were not controlled by label rates of the fungicides. Spore germination assays also were examined; for 10 isolates identified as sensitive by mycelial expansion assays, ED50 values for axoystrobin ranged from 0.0040 to 0.0047 μg/ml; for 25 isolates identified as QoI-resistant, 93 to 100% of the conidia germinated at azoxystrobin concentrations as high as 8.0 μg/ml relative to the nonamended check treatments. Mitochondrial cytochrome b genes from a subset of 15 isolates (12 resistant and 3 sensitive) were partially cloned and sequenced; all resistant isolates had an alanine substitution that corresponded to position 143 of the gene product. These results indicate that QoI resistance is present in California populations of C. cereale and is contributing to the difficulty in controlling this disease.

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Thiophanate-Methyl and Propiconazole Sensitivity in Sclerotinia homoeocarpa Populations from Golf Courses in Wisconsin and Massachusetts

Plant Disease ◽

10.1094/pdis-93-1-0100 ◽

2009 ◽

Vol 93 (1) ◽

pp. 100-105 ◽

Cited By ~ 28

Author(s):

Paul L. Koch ◽

Craig R. Grau ◽

Young-Ki Jo ◽

Geunhwa Jung

Keyword(s):

Golf Course ◽

Golf Courses ◽

Sclerotinia Homoeocarpa ◽

Putting Greens ◽

Thiophanate Methyl ◽

Development Of Resistance ◽

History Of ◽

Intensively Managed ◽

Pathogen Populations

Management of dollar spot, caused by the fungus Sclerotinia homoeocarpa, is dependent upon repeated fungicide applications in intensively managed turfgrass such as golf course putting greens and fairways. Repeated fungicide applications could potentially select for fungicide-resistant isolates and result in a reduction of disease control. The objectives of this study were to determine the degree of S. homoeocarpa in vitro sensitivity to the fungicides thiophanate-methyl and propiconazole using isolates collected from golf course putting greens, fairways, and roughs; and to determine the relationships of golf course age and fungicide history to the frequency of fungicide-insensitive isolates within the population. More than 1,400 S. homoeocarpa isolates were collected from putting greens, fairways, and roughs at six Wisconsin golf courses and one Massachusetts golf course and subjected to in vitro fungicide sensitivity assays with single discriminatory concentrations of thiophanate-methyl and propiconazole. Five of seven pathogen populations from rough areas were not significantly different from one another in propiconazole sensitivity. These populations were collectively the most sensitive to both fungicides and therefore, served as baseline populations for comparison with fungicide-exposed populations from putting greens and fairways. Greater propiconazole insensitivity was observed in populations collected from fairways and putting greens that received more frequent applications of the fungicide than those isolated from the roughs. In nearly all the golf courses, the frequency of thiophanate-methyl insensitivity was higher among isolates of S. homoeocarpa collected from fairways than from roughs regardless of the age of the golf course or history of benzimidazole use. Thus, while the development of resistance to propiconazole can be predicted in part by the relative frequency of demethylation inhibitor fungicide applications, the occurrence of populations resistant to thiophanate-methyl appears to be unrelated to recent use of the benzimidazole class of fungicides.

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

Plant Disease ◽

10.1094/pdis-94-6-0751 ◽

2010 ◽

Vol 94 (6) ◽

pp. 751-757 ◽

Cited By ~ 16

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.

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Comparison of media and diluents for enumeration of aerobic bacteria from Bermuda grass golf course putting greens

Journal of Microbiological Methods ◽

10.1016/s0167-7012(98)00088-8 ◽

1999 ◽

Vol 34 (3) ◽

pp. 193-202 ◽

Cited By ~ 12

Author(s):

M.L Elliott ◽

E.A Des Jardin

Keyword(s):

Bermuda Grass ◽

Golf Course ◽

Aerobic Bacteria ◽

Putting Greens

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Long-Term Roughstalk Bluegrass Control in Creeping Bentgrass Fairways

Weed Technology ◽

10.1017/wet.2017.72 ◽

2017 ◽

Vol 31 (5) ◽

pp. 714-723

Author(s):

Sandeep S. Rana ◽

Shawn D. Askew

Keyword(s):

Creeping Bentgrass ◽

Golf Course ◽

Cool Season ◽

Putting Greens ◽

Annual Bluegrass ◽

Turf Quality ◽

Normalized Difference Vegetative Index

Methiozolin is an isoxazoline herbicide that selectively controls annual bluegrass in cool-season turf and may control roughstalk bluegrass, another weedyPoaspecies that is problematic in many turfgrass systems. However, the majority of research to date is limited to evaluating methiozolin efficacy for annual bluegrass control in creeping bentgrass putting greens. Research was conducted comparing various application regimes of methiozolin and other herbicides for long-term roughstalk bluegrass control in creeping bentgrass golf fairways. Methiozolin-only treatments did not injure creeping bentgrass or reduce normalized difference vegetative index (NDVI) at 2 golf course locations based on 20 evaluation dates over a 2.5-yr period. The 2.5-yr average turf quality generally declined as roughstalk bluegrass control increased due to transient turf cover loss. At 1 yr after last treatment, methiozolin at 1500 g ai ha-1applied four times in fall reduced roughstalk bluegrass cover 85%. This was equivalent to methiozolin at 1000 g ha-1applied four times in fall, but greater than low rates of methiozolin applied four times in spring or twice in fall and spring. Amicarbazone, primisulfuron, and bispyribac-sodium alone either did not effectively reduce roughstalk bluegrass cover, or did so at the expense of increased creeping bentgrass injury. Results of this study suggest that methiozolin alone or tank-mixed with amicarbazone or primisulfuron is an effective long-term approach for selectively controlling roughstalk bluegrass in creeping bentgrass.

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Use of High-pressure Injection to Alleviate Type-I Fairy Ring Symptoms in Turfgrass

HortTechnology ◽

10.21273/horttech.15.1.0169 ◽

2005 ◽

Vol 15 (1) ◽

pp. 169-172 ◽

Cited By ~ 7

Author(s):

M.A. Fidanza ◽

P.F. Colbaugh ◽

M.C. Engelke ◽

S.D. Davis ◽

K.E. Kenworthy

Keyword(s):

High Pressure ◽

Root Zone ◽

Creeping Bentgrass ◽

Golf Course ◽

Type I ◽

Putting Greens ◽

Pressure Injection ◽

Spray Method ◽

Putting Green ◽

High Pressure Injection

Fairy ring is a common and troublesome disease of turfgrasses maintained on golf course putting greens. Type-I fairy ring is especially destructive due to the development of hydrophobic conditions in the thatch and root zone, thus contributing to turfgrass injury and loss. The objective of this 2-year field study was to evaluate the application and novel delivery method of two fungicides and a soil surfactant for curative control of type-I fairy ring in a 20-year-old creeping bentgrass [Agrostis palustris (synonym A. stolonifera)] putting green. In both years, all treatments were applied twice on a 28-day interval. In 1998, flutolanil and azoxystrobin fungicides were applied alone and in combination with Primer soil surfactant by a conventional topical spray method, and fungicides without Primer applied via high-pressure injection (HPI). Acceptable type-I fairy ring control was observed in plots treated with flutolanil plus Primer, HPI flutolanil, azoxystrobin alone, azoxystrobin plus Primer, or HPI azoxystrobin. In 1999, treatments were HPI flutolanil, HPI flutolanil plus Primer, HPI azoxystrobin, HPI water only, and aeration only. Acceptable type-I fairy ring control was observed in plots treated with HPI flutolanil plus Primer or HPI azoxystrobin. HPI of fungicides alone or in combination with a soil surfactant may be a viable option for alleviating type-I fairy ring symptoms on golf course putting greens.

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Flutolanil for Control of Necrotic Fairy Rings on Bermudagrass Putting Greens

HortTechnology ◽

10.21273/horttech.12.4.656 ◽

2002 ◽

Vol 12 (4) ◽

pp. 656-659 ◽

Cited By ~ 4

Author(s):

Monica L. Elliott ◽

Robert B. Hickman ◽

Mark Hopkins

Keyword(s):

Untreated Control ◽

Cynodon Dactylon ◽

Preventive Treatment ◽

Golf Course ◽

Putting Greens ◽

Severe Problem ◽

Common Cause ◽

Preventive Activity ◽

Fairy Rings

Type 1 (necrotic) fairy rings in turfgrass result in dead or badly damaged grass. This type of fairy ring is a severe problem on golf course greens as they interfere with the aesthetics and playability of the putting surface. In Florida, Lycoperdon spp., basidiomycetes that produce puffball mushrooms, have been implicated as a common cause of Type 1 fairy rings on hybrid bermudagrass (Cynodon dactylon × C. transvaalensis) putting greens. The fungicide flutolanil has basidiomycetes as the sole fungal target. It is also the only carboxin-related fungicide registered for use on turfgrass. Two experiments were conducted to examine the effect of flutolanil as a curative and preventive treatment for fairy ring caused by Lycoperdon. One experiment, established after the rings were present, determined that flutolanil significantly reduced mushroom production. The second experiment was conducted on a golf course that had experienced Type 1 fairy rings previously. One-half of each of nine putting greens was treated with flutolanil on a preventive basis. The other half of each green served as an untreated control. Type 1 fairy rings, due to Lycoperdon, developed only on the untreated control half of each green. These experiments confirm that flutolanil does have curative and preventive activity against Lycoperdon spp. that cause Type 1 fairy rings.

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