scholarly journals Identification of a New Waitea circinata Variety Causing Basal Leaf Blight of Seashore Paspalum

Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 515-522 ◽  
Author(s):  
S. J. Kammerer ◽  
L. L. Burpee ◽  
P. F. Harmon
Keyword(s):  
Cynodon Dactylon ◽  
Warm Season ◽  
Creeping Bentgrass ◽  
Leaf Blight ◽  
Golf Course ◽  
New Variety ◽  
Seashore Paspalum ◽  
Basal Leaf ◽  
Poa Trivialis ◽  
Waitea Circinata

Seashore paspalum (Paspalum vaginatum) is a saline-tolerant, warm-season turfgrass species popular for golf course use in tropical and subtropical climates. A new variety of Waitea circinata (proposed as W. circinata var. prodigus) is described as the causal agent of basal leaf blight, a novel disease of seashore paspalum. Foliar necrosis and canopy thinning of seashore paspalum were observed on three different golf course fairways in Florida over an 18-month period. Five isolates with profuse, pink to yellow mycelia and small, salmon-colored or yellow to light-brown sclerotia were cultured from diseased turf foliage. Isolates grew rapidly over a temperature range of 25 to 35°C and were initially identified as an uncharacterized variety of W. circinata. Internal transcribed spacer sequences of rDNA from the isolates were compared with sequences from previously described W. circinata varieties. The paspalum isolates formed a phylogenetic clade that was distinct from the other W. circinata varieties. Pathogenicity was confirmed on ‘SeaDwarf’ and ‘SeaIsle Supreme’ seashore paspalum, ‘Penncross’ creeping bentgrass (Agrostis stolonifera), ‘Senesta’ bermudagrass (Cynodon dactylon), and ‘Dark Horse’ roughstalk bluegrass (Poa trivialis). The geographical distribution and potential impact of basal leaf blight is unknown. However, the range of potential turfgrass hosts and environmental conditions conducive for disease development suggest that the pathogen may infect other species in addition to seashore paspalum.

scholarly journals First Report of Brown Ring Patch Caused by Waitea circinata var. circinata on Poa trivialis in Florida

Plant Disease ◽  
2008 ◽  
Vol 92 (11) ◽  
pp. 1586-1586
Author(s):  
N. Flor ◽  
P. Harmon ◽  
L. Datnoff ◽  
R. Raid ◽  
R. Nagata
Keyword(s):  
Cynodon Dactylon ◽  
Aerial Mycelium ◽  
Creeping Bentgrass ◽  
Internal Transcribed Spacers ◽  
Wheat Grains ◽  
First Report ◽  
Poa Trivialis ◽  
Putting Green ◽  
Plastic Bag ◽  
Waitea Circinata

Brown ring patch is a newly described disease of cool-season turfgrass first reported in Japan on creeping bentgrass (Agrostis palustris) (2) and later reported in California on annual bluegrass (Poa annua) (1). The disease is characterized by either patches or rings of discolored to blighted turfgrass that can range from a few centimeters to a meter in diameter. Affected turfgrass plants turn chlorotic and can be blighted from the crown to the leaf tips. Blight symptoms have been associated with fluffy white-to-cream aerial mycelium after extended incubation of the sample. Symptoms including patches of blighted turfgrass approximately 10 cm in diameter were observed on roughstalk bluegrass (Poa trivialis) that had been overseeded onto a dormant ‘Tifdwarf’ bermudagrass (Cynodon dactylon) putting green in Palatka, FL. A sample was submitted by the superintendent in June 2005 because symptoms were confused with dollar spot and a fungicide resistance issue was suspected. The sample produced abundant aerial mycelium after incubation. The pathogen was isolated on potato dextrose agar amended with rifampicin (100 ppm) and streptomycin (100 ppm) from Poa plants surface disinfested with 70% ethanol for 30 s. Colony and sclerotia morphology were consistent with Waitea circinata var. circinata as previously described (1,2). The teleomorph W. circinata var. circinata was not observed on plant material or culture plates. Amplified fragments of rDNA including internal transcribed spacers from the isolate were sequenced bidirectionally from four bacterial clones. The consensus sequences (GenBank Accession Nos. FJ029103, FJ029104, FJ029105, and FJ029106) matched with 99% homology (99% sequence overlap) isolate TRGC1.1 of W. circinata var. circinata described by Wong, NCBI Accession No. DQ900586 (1). Pots of ‘Cypress’ roughstalk bluegrass that were 1 week postemergence were inoculated with the pathogen using 10 infested wheat grains. Plants were incubated at 25°C in a sealed plastic bag with a moist paper towel in the bottom. Hyphae grew from the grains and colonized the grass. Individual plants began to turn chlorotic within 3 days and greater than 90% of the turf in pots was dead after 1 week. The fungus was reisolated from affected plants. Control pots were inoculated with uninfested wheat grains and showed no disease symptoms after 1 week. Inoculations were repeated twice more with the same results. To our knowledge, this is the first report of brown ring patch on P. trivialis in Florida. References: (1) K. A. de la Cerda et al. Plant Dis. 91:791, 2007. (2) T. Toda et al. Plant Dis. 89:536, 2005.

scholarly journals First Report of Basal Leaf Blight of Kikuyugrass Caused by Waitea circinata var. prodigus in Southern California

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 767-767 ◽  
Author(s):  
C.-M. Chen ◽  
G. W. Douhan ◽  
F. P. Wong
Keyword(s):  
Southern California ◽  
Pcr Amplification ◽  
Petri Dish ◽  
Leaf Blight ◽  
Golf Course ◽  
Invasive Weed ◽  
Basal Leaf ◽  
First Report ◽  
C4 Grass ◽  
Waitea Circinata

Kikuyugrass (Pennisetum clandestinum) is a C4 grass and invasive weed adopted for use as a primary turf species in some golf course fairways and roughs in southern California. In September 2008, a new Rhizoctonia-like fungus was isolated from a diseased kikuyugrass sample received from a golf course fairway in Oceanside, CA. The kikuyugrass was from a mature stand (>20 years old) that was maintained at a height of approximately 1.25 cm. Symptoms on kikyuygrass developed initially as irregular, blighted, chlorotic patches, several centimeters to one meter, which occurred during a period of warm, humid weather (27 to 29°C maximum daytime temperature, 75 to 85% average relative humidity) on a small part of one fairway. Affected areas became brown and necrotic as the disease progressed. Leaf chlorosis and stem rot were observed on affected plants. The organism was isolated by placing symptomatic leaves on acidified one-quarter-strength potato dextrose agar (PDA) (600 μl of 85% lactic acid per liter of medium) in a petri dish (1). A colony of a Rhizoctonia-like fungus with yellow aerial hyphae, multinucleate hyphal cells, and irregularly shaped, golden brown sclerotia (4 to 7 mm) developed within 30 days at 28°C. The rDNA internal transcribed spacer (ITS) sequence was obtained (GenBank Accession No. HQ850254) using PCR amplification with primers ITS1F and ITS4 (1,2), and a BLAST search showed 100% similarity with Waitea circinata var. prodigus (GenBank Accession No. HM597145), which had recently been described as the cause of basal leaf blight of seashore paspalum (Paspalum vaginatum), another C4 grass (3), in Florida. Colony morphology and other physical characteristics were similar but not completely identical to those from Florida, reflecting the reported morphological variation inherent in the pathogen (3). Koch's postulates were performed by growing this isolate on PDA in a petri dish for 7 days, homogenizing the culture with 100 ml of sterilized water, filtering the suspension through two layers of cheesecloth, and pipetting 10 ml of the mycelial suspension onto the foliage and stems of 4-week-old AZ-1 kikuyugrass plants grown in UC-soilless-mix in 7.5-cm-diameter pots (4). Control plants were treated with a homogenized and filtered dish of PDA only. There were three replicate pots for inoculated and noninoculated treatments and the experiment was repeated independently three times. All of the pots were incubated in a moist chamber with a 12-h light period at 28°C. Yellow lesions were observed on leaves and stems of inoculated plants 4 days postinoculation and necrosis developed 8 days later in all experiments. The same organism was isolated from symptomatic plants. The control plants did not exhibit any symptoms. To our knowledge, this is the first report of basal leaf blight caused by W. circinata var. prodigus on kikuyugrass in California and the first report of this pathogen affecting turfgrass in the western United States. References: (1) C. M. Chen et al. Plant Dis. 93:906, 2009 (2) K. de la Cerda et al. Plant Dis. 91:791, 2007. (3) S. J. Kammerer et al. Plant Dis. 95:515, 2011. (4) T. Toda et al. J. Gen. Plant Pathol. 73:379, 2007.

scholarly journals Salinity Tolerance of Selected Seashore Paspalums and Bermudagrasses: Root and Verdure Responses and Criteria

HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 1143-1147 ◽  
Author(s):  
Geungjoo Lee ◽  
Robert N. Carrow ◽  
Ronny R. Duncan
Keyword(s):  
Salinity Tolerance ◽  
Cynodon Dactylon ◽  
Sand Dunes ◽  
Total Yield ◽  
Warm Season ◽  
Sand Culture ◽  
Root Characteristics ◽  
Seashore Paspalum ◽  
Absolute Growth ◽  
Total Growth

Seashore paspalum (Paspalum vaginatum Swartz) is a warm season turfgrass that survives in sand dunes along coastal sites and around brackish ponds or estuaries. The first exposure to salt stress normally occurs in the rhizosphere for persistent turfgrass. Information on diversity in salinity tolerance of seashore paspalums is limited. From Apr. to Oct. 1997, eight seashore paspalum ecotypes (SI 94-1, SI 92, SI 94-2, `Sea Isle 1', `Excalibur', `Sea Isle 2000', `Salam', `Adalayd') and four bermudagrass (Cynodon dactylon × C. transvaalensis Butt-Davy) cultivars (`Tifgreen', `Tifway', `TifSport', `TifEagle') were investigated for levels of salinity tolerance based on root and verdure responses in nutrient/sand culture under greenhouse conditions. Different salt levels (1.1 to 41.1 dS·m-1) were created with sea salt. Measurements were taken for absolute growth at 1.1 (ECw0; electrical conductivity of water), 24.8 (ECw24), 33.1 (ECw 32), and 41.1 dS·m-1 (ECw40), threshold ECw, and ECw for 25% growth reduction from ECw0 growth (ECw25%). Varying levels of salinity tolerance among the 12 entries were observed based on root, verdure, and total plant yield. Ranges of root characteristics were inherent growth (ECw0) = 0.20 to 0.61 g dry weight (DW); growth at ECw24 = 0.11 to 0.47 g; growth at ECw32 = 0.13 to 0.50 g; growth at ECw40 = 0.13 to 0.50 g; threshold ECw = 3.1 to 9.9 dS·m-1; and ECw25% = 23 to 39 dS·m-1. For verdure, ranges were inherent growth at ECw0 = 0.40 to 1.07 g DW; growth at ECw40 = 0.31 to 0.84 g; and ratio of yields at ECw40 to ECw0 = 0.54 to 1.03. Ranges for total growth were inherent growth at ECw0 = 0.72 to 2.66 g DW; growth at ECw24 = 0.55 to 2.23 g; growth at ECw32 = 0.54 to 2.08 g; growth at ECw40 = 0.52 to 1.66 g; threshold ECw = 2.3 to 12.8 dS·m-1; and ECw25% = 16 to 38 dS·m-1. Significant salinity tolerance differences existed among seashore paspalums and bermudagrasses as demonstrated by root, verdure, and total growth measurements. When grasses were ranked across all criteria exhibiting a significant F test based on root, verdure, and total growth, the most tolerant ecotypes were SI 94-1 and SI 92. Salinity tolerance of bermudagrass cultivars was relatively lower than SI 94-1 and SI 92. For assessing salinity tolerance, minimum evaluation criteria must include absolute growth at ECw0 and ECw 40 dS·m-1 for halophytes, but using all significant parameters of root and total yield is recommended for comprehensive evaluation.

scholarly journals Identification of Waitea circinata as a Pathogen of the Moss Bryum argenteum var. argenteum on a Golf Course Fairway

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 289-289
Author(s):  
N. Mitkowski ◽  
A. Chaves
Keyword(s):  
Fungal Pathogen ◽  
Aerial Mycelium ◽  
Creeping Bentgrass ◽  
The United States ◽  
Early Summer ◽  
Control Treatment ◽  
Golf Course ◽  
Moss Species ◽  
Bryum Argenteum ◽  
Waitea Circinata

Waitea circinata Warcup and Talbot (also referred to as W. circinata var. circinata) is an important fungal pathogen of amenity turfgrasses and is especially problematic on Poa annua in putting greens in the late spring or early summer. The pathogen was first identified in 2005 from Japan and has since been seen widely throughout the United States (1,2). On occasion, the pathogen has been observed attacking creeping bentgrass (Agrostis stolonifera) but is typically less virulent. Disease symptoms include prominent yellow rings appearing throughout established turf and moderate leaf necrosis. In the summer of 2012, moss from a section of fairway on a golf course in Edwards, CO was observed to be rapidly killed by a fungal pathogen producing copious amounts of aerial mycelium and appearing similar to Waitea microscopically. Aerial mycelium was transferred to acidified potato dextrose agar (PDA) (1 ml lactic/L). After 1 day at 25°C, mycelia were transferred to PDA. After 2 weeks, plates were covered with white aerial mycelium and separate, spherical, 0.5-mm diameter, salmon-colored sclerotia, which turned dark brown within a few days and were produced submerged throughout the media. Spores were never produced and right-angled branching of mycelia, characteristic of Waitea, was observed in mature cultures. Mycelial plugs were incubated in nutrient broth and DNA was extracted using a MoBio Power Plant DNA extraction kit. Amplification of ribosomal ITS sequences with ITS4 and ITS5 resulted in a 100% identity match with GenBank sequence HM807352, W. circinata var. circinta (3). To demonstrate pathogenicity on Bryum argenteum, unaffected moss from the submitted sample (identified as B. argenteum var. argenteum via 100% sequence identity with the published GenBank sequence GU907062) was removed from the originally submitted sample and placed in separate growth chambers at 95% humidity and 21, 26, and 31°C. An additional experiment employed local B. agenteum plants collected from the URI Kingston, RI campus. Agar plugs from the isolated W. circinata were placed on top of the moss and within 2 days the fungus had caused complete mortality at all three temperatures. The experiment was also undertaken using the same environmental conditions with 5-week-old annual bluegrass (P. annua) and creeping bentgrass cv. A4 grown from seed. Plants were inoculated with infected rye grains at 31, 26, and 21°C. After 1 week, the P. annua plants showed significant mortality at 26 and 31°C with little infection at 21°C and the A. stolonifera plants showed moderate mortality at 26°C and little infection at the other two temperatures. All experiments utilized an additional uninoculated control treatment that showed no moss/turf necrosis or mortality. Experiments were all repeated once and used three replicates per experiment. While moss is not intentionally cultivated on golf courses, it does occur with regularity and often presents itself as a difficult pest to manage. This particular isolate of W. circinata has identical ribosomal and physiological characteristics of the reported P. annua pathogen but can attack one moss species and may be a possible candidate for selective biological control of moss in golf course settings. It is unclear how widespread moss pathogenicity is within W. circinata. References: (1) E. N. Njambere et al. Plant Dis. 95:78 2011. (2) T. Toda et al. Plant Dis. 89:536, 2005. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications, 1990.

scholarly journals Influence of Fall-applied Treatments on Spring Transition of an Overseeded Bermudagrass Green

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 424-428 ◽  
Author(s):  
Robert L. Green ◽  
Grant J. Klein ◽  
Francisco Merino ◽  
Victor Gibeault
Keyword(s):  
Cynodon Dactylon ◽  
Acid Ethyl Ester ◽  
Golf Course ◽  
Seed Rate ◽  
Study Results ◽  
Spring Transition ◽  
Poa Trivialis ◽  
Turfgrass Quality ◽  
Second Year ◽  
Seedbed Preparation

Bermudagrass [Cynodon dactylon (L.) Pers × C. transvaalensis Burtt-Davy] greens across the southern United States are normally overseeded in the fall to provide a uniform green playing surface and tolerance to wear during winter bermudagrass dormancy. The spring transition from overseed grass back to bermudagrass is a major problem associated with overseeding because there can be a decline in putting green quality and playability. There have been recommendations, but relatively few published reports, on the effect of treatments associated with seedbed preparation and overseeding on bermudagrass spring transition. The objective of this 2-year study was to determine if spring transition of an overseeded `Tifgreen' bermudagrass green was influenced by fall-applied scalping level, chemical, and seed rate treatments. Treatment factors and levels were designed to reflect the range of practices used by golf course superintendents in the region at the time of the study. The green was located in the Palm Springs, Calif., area, which has relatively mild winters and a low desert, southern California climate. The first year of the study was from Sept. 1996 to July 1997 and the second year was from Sept. 1997 to July 1998. Scalping level treatments included a moderate and severe verticut and scalp; chemical treatments included a check, trinexapac-ethyl at two rates, and diquat; and seed rate treatments included a high and low rate of a mixture of `Seville' perennial ryegrass (Lolium perenne L.) and `Sabre' rough bluegrass (Poa trivialis L.). The plot was maintained under golf course conditions and a traffic simulator was used to simulate golfer traffic. Visual ratings of percent green bermudagrass coverage were taken every 3 weeks from 20 Feb. 1997 to 29 July 1997 and from 11 Nov. 1997 to 22 July 1998. Visual turfgrass quality ratings were taken during the second year of the study. Results showed that spring transition was not influenced by fall-applied treatments during both years. Also, visual turfgrass quality was not influenced during the second year. Chemical names used: [4(cyclopropyl-αhydroxy-methylene) -3,5-dioxocyclohexanecarboxylic acid ethyl ester (trinexapac-ethyl); 9,10-dihydro-8a-, 10a-diazoniaphenanthrene (diquat).

Influence of Spring-Applied Herbicides on Bermudagrass (Cynodon dactylon) Greens Overseeded with Roughstalk Bluegrass (Poa trivialis)

1998 ◽  
Vol 12 (1) ◽  
pp. 1-6 ◽  
Author(s):  
B. Jack Johnson
Keyword(s):  
Cynodon Dactylon ◽  
Warm Season ◽  
Severe Injury ◽  
Severely Injured ◽  
Warm Season Grass ◽  
Poa Trivialis

Premergence (PRE) herbicides were applied to a bermudagrass golf green overseeded with ‘Laser’ roughstalk bluegrass during 1995 and 1996 to determine their effects on roughstalk bluegrass injury and on the transition from a mixed cool- and warm-season grass back to the permanent bermudagrass. Roughstalk bluegrass tolerated single March applications of trifluralin plus benefin at 2.2 kg/ha, pendimethalin at 3.4 kg/ha, dithiopyr at 0.6 kg/ha, prodiamine at 0.8 kg/ha, bensulide plus oxadiazon at 8.4 kg/ha, and bensulide at 11.2 kg/ha. A single March application of oxadiazon plus benefin at 3.4 kg/ha severely injured (35%) the overseeded turf in 1 yr, but not when 1.7 kg/ha was applied in March and repeated in May. One-half recommended rates of oxadiazon and bensulide plus oxadiazon applied in March did not cause any undesirable injury, but when repeated in May, moderate to severe injury (28 to 33%) occurred in June. Oryzalin at ≥ 1.1 kg/ha, benefin plus oryzalin at ≥ 1.1 kg/ha, and oxyfluorfen plus oryzalin at ≥ 1.7 kg/ha severely injured (≥ 35%) roughstalk bluegrass. The rate of transition of mixed roughstalk bluegrass and bermudagrass back to permanent bermudagrass was not affected by any of the PRE herbicides except when oryzalin was applied alone or in combination with benefin or oxyfluorfen.

Effect of Benefin and DCPA on Overseeded Grasses Maintained as Putting Greens

Weed Science ◽  
1973 ◽  
Vol 21 (6) ◽  
pp. 528-531 ◽  
Author(s):  
G. E. Coats ◽  
C. Y. Ward ◽  
E. L. McWhirter
Keyword(s):  
Cynodon Dactylon ◽  
Lolium Multiflorum ◽  
Creeping Bentgrass ◽  
Italian Ryegrass ◽  
Agrostis Palustris ◽  
Putting Greens ◽  
Red Fescue ◽  
Poa Trivialis ◽  
Putting Green ◽  
Green Conditions

Overseeded rough bluegrass (Poa trivialisL. ‘Danish common’) and Italian ryegrass (Lolium multiflorumLam. ‘Gulf’) maintained under putting green conditions were more susceptible to benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine) and DCPA (dimethyl tetrachloroterephthalate) than creeping bentgrass (Agrostis palustrisHud. ‘Penn-cross’), red fescue (Festuca rubraL. ‘Dawson’), or perennial ryegrass (Lolium perenneL. ‘Medalist II’). February applications of 1.68 or 3.36 kg/ha of benefin and 6.72 or 13.44 kg/ha of DCPA caused significantly more discoloration and reductions in density than equivalent rates applied in March or April. Benefin was more injurious than DCPA to all overseeded species as judged by quality or density. DCPA caused significant delays in the breaking of dormancy of bermudagrass [Cynodon dactylon(L.) Pers. ‘Tifdwarf’].

scholarly journals Taxonomic Diversity of Rhizosphere Bacteria in Golf Course Putting Greens at Representative Sites in the Southeastern United States

HortScience ◽  
2008 ◽  
Vol 43 (2) ◽  
pp. 514-518 ◽  
Author(s):  
Monica L. Elliott ◽  
J.A. McInroy ◽  
K. Xiong ◽  
J.H. Kim ◽  
H.D. Skipper ◽  
...  
Keyword(s):  
South Carolina ◽  
Cynodon Dactylon ◽  
Similarity Index ◽  
Acid Methyl Ester ◽  
Creeping Bentgrass ◽  
Taxonomic Diversity ◽  
Golf Course ◽  
Culturable Bacteria ◽  
Bacterial Populations ◽  
Putting Greens

Taxonomic diversity of bacteria associated with golf course putting greens is a topic that has not been widely explored. The purpose of this project was to isolate and identify culturable bacteria from the rhizosphere of creeping bentgrass (Agrostris palustris Huds.) at two sites (Alabama and North Carolina) and hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] at two sites (Florida and South Carolina) for a minimum of 3 years with sampling initiated after the construction process. Randomly selected colonies were identified using gas chromatography for analysis of fatty acid methyl ester profiles. Over 9000 isolates were successfully analyzed. When a similarity index of 0.300 or higher was used, the average number of unidentifiable isolates was 38.6%. The two dominant genera in both bentgrass and bermudagrass rhizospheres were Bacillus and Pseudomonas with Bacillus dominant in bermudagrass and Pseudomonas dominant or equal to Bacillus in bentgrass. Other genera that comprised at least 1% of the isolates at all four sites were Clavibacter, Flavobacterium, and Microbacterium. Arthrobacter also comprised a significant portion of the bacterial isolates in the bentgrass rhizosphere, but not the bermudagrass rhizosphere. Overall, there were 40 genera common to all four sites. At the species level, there were five that comprised at least 1% of the isolates at each location: B. cereus, B. megaterium, C. michiganensis, F. johnsoniae, and P. putida. As has been reported for many grasses, we found considerable taxonomic diversity among the culturable bacterial populations from the rhizospheres of bentgrass and bermudagrass grown in sand-based putting greens.

scholarly journals Cover Technology Influences Warm-season Grass Establishment from Seed

2010 ◽  
Vol 20 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Aaron J. Patton ◽  
Jon M. Trappe ◽  
Michael D. Richardson
Keyword(s):  
Cynodon Dactylon ◽  
Warm Season ◽  
Buchloe Dactyloides ◽  
Seashore Paspalum ◽  
Active Radiation ◽  
Warm Season Grass ◽  
Paspalum Vaginatum ◽  
Eremochloa Ophiuroides ◽  
Grass Establishment ◽  
Warm Season Grasses

Covers, mulches, and erosion-control blankets are often used to establish turf. There are reports of various effects of seed cover technology on the germination and establishment of warm-season grasses. The objective of this study was to determine how diverse cover technologies influence the establishment of bermudagrass (Cynodon dactylon), buffalograss (Buchloe dactyloides), centipedegrass (Eremochloa ophiuroides), seashore paspalum (Paspalum vaginatum), and zoysiagrass (Zoysia japonica) from seed. Plots were seeded in June 2007 or July 2008 with the various turfgrass species and covered with cover technologies, including Curlex, Deluxe, and Futerra products, jute, Poly Jute, polypropylene, straw, straw blanket, Thermal blanket, and the control. Establishment was reduced in straw- and polyethylene-covered plots due to decreased photosythentically active radiation penetration or excessive temperature build-up, respectively. Overall, Deluxe and Futerra products, jute, and Poly Jute allowed for the highest establishment of these seeded warm-season grasses.

scholarly journals First Report of Brown Ring Patch on Poa annua Caused by Waitea circinata var. circinata in West Virginia

Plant Disease ◽  
2010 ◽  
Vol 94 (11) ◽  
pp. 1379-1379
Author(s):  
S. J. McDonald ◽  
R. M. Averell ◽  
M. E. Glass ◽  
H. M. Young ◽  
T. H. Mysliwiec ◽  
...  
Keyword(s):  
West Virginia ◽  
Aerial Mycelium ◽  
Creeping Bentgrass ◽  
Poa Annua ◽  
Golf Course ◽  
First Report ◽  
5.8S Rdna ◽  
Annual Bluegrass ◽  
Agar Plug ◽  
Waitea Circinata

In mid-November 2009, thin, yellow, and irregular-shaped scalloped rings 10 to 25 cm in diameter were observed on 5 to 10% of a golf course putting green in Charles Town, WV. The 20-year-old USGA-specification sand-based green was mowed at 3.1-mm height and consisted of 60% annual bluegrass (Poa annua L.) and 40% creeping bentgrass (Agrostis stoloniferous L. ‘Putter’). Minimum and maximum daily air temperature ranged from 2 to 22°C, respectively, with 38 mm of rainfall during the appearance of rings symptoms. Only affected annual bluegrass plants exhibited a peculiar yellow chlorosis of the upper and lower leaves. A single fungal isolate was obtained from active mycelium found within symptomatic annual bluegrass leaves and grown on potato dextrose agar (PDA) amended with chloramphenicol (0.1 g/liter). Fungal colony morphology (i.e., light yellow with irregular-shaped 2- to 4-mm-diameter sclerotia first appearing off-white but progressing to brown by 21 to 28 days in culture) and sequencing of the internal transcribed spacer (ITS) 5.8S rDNA region with primers ITS1 and ITS4 confirmed the isolate as Waitea circinata var. circinata (Warcup & Talbot) with ≥99% sequence identity with GenBank Accession No. FJ755889 (1,2,4). To confirm pathogenicity, a 6-mm-diameter plug of the isolate was removed from the expanding edge of a 4-day-old culture grown on PDA and placed in contact with the lower leaves of 12-week-old annual bluegrass (0.001 g of surface-sterilized seed per cm2) grown in 5- × 5-cm plastic pots of autoclaved 85% sand and 15% potting soil. Six pots were inoculated with the isolate and six pots were inoculated with an isolate-free agar plug and then placed in a moist chamber at 28°C. Leaf chlorosis and aerial mycelium was observed in all six inoculated pots 8 to 10 days after inoculation, and symptoms were similar to those expressed in the field. All noninoculated plants remained healthy and asymptomatic. W. circinata var. circinata was reisolated from symptomatic leaves and again confirmed by colony traits and sequencing of the ITS-5.8S rDNA region and submitted as GenBank Accession No. HM807582. To our knowledge, this is the first report of brown ring patch in West Virginia and could be economically important because of intensive fungicide practices used to maintain high-quality putting greens on golf courses (3). References: (1) C. Chen et al. Plant Dis. 91:1687, 2007. (2) K. de la Cerda et al. Plant Dis. 91:791, 2007. (3) J. Kaminski and F. Wong. Golf Course Manage. 75:98, 2007. (4) T. Toda et al. Plant Dis. 89:536, 2005.

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