Search

Low cost and favorable handling characteristics make urea (46-0-0) a leading nitrogen source for frequent, foliar N fertilization of golf course putting greens in season. Yet few field investigations of resulting NH3 volatilization from putting greens have been directed. Meanwhile, NH3 emissions degrade air and surface water quality. Our objective was to quantify NH3 volatilization following practical, low-N rate, and foliar application of commercial urea-N fertilizers. Over the 2019 and 2020 growing seasons in University Park, PA, USA, an industrial vacuum pump, H3BO3 scrubbing flasks, and sixteen dynamic flux chambers were employed in four unique experiments to measure NH3 volatilization from creeping bentgrass putting greens (Agrostis stolonifera L. 'Penn G2') in the 24 h period ensuing foliar application of urea based-N at a 7.32 or 9.76 kg/ha rate. Simultaneous and replicated flux chamber trapping efficiency trials showing 35% mean NH3 recovery were used to adjust NH3 volatilization rates from treated plots. Under the duration and conditions described, 3.1 to 8.0% of conventional urea N volatilized from the putting greens as NH3. Conversely, 0.7 to 1.1% of methylol urea liquid fertilizer (60% short-chain methylene urea) or 0.7 to 2.2% of urea complimented with dicyandiamide (DCD) and N-(n-butyl) thiophosphoric triamide (NBPT) volatilized as NH3. [ABSTRACT FROM AUTHOR]

Flutolanil and pentachloronitrobenzene (PCNB) are fungicides used to control or suppress foliar and soil borne diseases in turf and ornamental crops. On golf courses, sports fields, sod farms and commercial lawns these fungicides are used as preventive treatments to combat snow mold, brown patch and fairy ring. Depending on the aquatic organism, flultolanil and PCNB are considered to be moderately to highly toxic. Therefore runoff or drift from treated areas may be hazardous to organisms in adjacent aquatic sites. This research compared the transport of flutolanil and PCNB with runoff from turfgrass managed as a golf course fairway. The quantity of fungicide transported with runoff and observations reported with the chemographs followed trends in agreement with the chemical properties of the compounds. Overall, we observed the rate of transport for flutolanil was greater than PCNB, which contributed to the more than 12 times larger load (µg/m 2 ) of flutolanil transported off-site at the conclusion of the simulated storm runoff. A better understanding of the off-site transport of pesticides with runoff is needed to make informed decisions on management practices to reduce potential adverse effects on non-target organisms, as well as maintain control of targeted pests in the area of application. In addition, data obtained with this research can be used in model simulations to predict nonpoint source pollution potentials beyond experimental conditions. [ABSTRACT FROM AUTHOR]

Glyphosate is routinely used to eradicate existing turf in golf course fairway renovations. However, current label recommendations suggest delaying cultivation of glyphosate treated areas for 7 days. A 2-year field study was conducted to assess how various seedbed preparation techniques (i.e., verticutting, core-cultivation, or verticutting + core-cultivation) influence glyphosate efficacy on creeping bentgrass fairway turf when completed at various intervals shortly after application [0-7 days before cultivation (DBC)]. Percent green cover declined from initial values of ≈90% to ≤0.2% at the end of the study after glyphosate application at all timings, regardless of cultivation during both years. All cultivated plots had 37.9% to 72.3%, or 5.9% to 62.1% less green cover compared with noncultivated plots when glyphosate was applied ≤3 days before cultivation in 2014 and 2015, respectively. Generally, the number of days until green cover reached 1% (GC1) ranged from 6.6 to 11.1 in 2014 and 5.2 to 6.9 in 2015. Within glyphosate application timings, no differences in GC1 were observed between cultivated and noncultivated treatments in 2014, except at 0 DBC. The GC1 for verticutting was 5.1 days longer than noncultivated plots; however, all other cultivation treatments were equivalent to noncultivated plots when glyphosate was applied 0 DBC. All cultivation treatments reduced GC1 1.7 to 2.5 days compared with the no cultivation treatment, regardless of glyphosate application timing in 2015. Results from this study indicate that cultivation of creeping bentgrass fairway turf within 7 days of glyphosate application is not detrimental to long-term herbicide efficacy, and in some cases may actually enhance the rate of decline of glyphosate treated creeping bentgrass. [ABSTRACT FROM AUTHOR]

Turf grasses entering the Nordic winter must be healthy and have sufficient reserves. The objective of this research was to investigate the effects of autumn mowing height and late autumn fertilization (LAF) on golf greens. Eighteen experiments were carried out on golf courses in Finland (3), Sweden (3) and Norway (7), nine in 2008/2010 and nine in 2009/2010. Starting in late August or early September, the greens were cut for about one month at 100% or 150% of the height practiced during summer. Within each mowing height, 2 g N/m2 was applied in a complete, mineral fertilizer when the turf had stopped growing. Unfertilized control plots were established using tarpaulin covers, three within each mowing height. The grass species were creeping bent grass (Agrostis stolonifera L.: 6 expt.), red fescue (Festuca rubra: 4 expt.), velvet bent grass (Agrostis canina: 3 expt.), and annual meadow grass (Poa annua: 5 expt). Overall winter damage, turf coverage and overall turf impression were assessed in spring. The results showed different responses among species: (1) Red fescue-dominated greens had significantly better turf grass coverage and overall impression after LAF. Higher mowing tended to improve spring performance. (2) LAF improved coverage and overall impression, but did not reduce winter damage or winter diseases on creeping bent grass greens. There was no effect of mowing height. (3) Velvet bent grass greens showed no significant effect of either mowing height or LAF. On annual meadow grass greens higher mowing improved spring performance more than LAF. Since there were no negative effects of LAF, we conclude that LAF is beneficial for golf greens under Nordic conditions. The effect of higher mowing in autumn differed among species, but can be recommended for annual meadow grass and red fescue. Further research is needed to find optimal time and fertilizer rate. [ABSTRACT FROM PUBLISHER]

The encroachment of moss on creeping bentgrass (Agrostis stolonifera L.) golf greens is a significant problem throughout the world. Although chemical control products for moss exist many are not registered for this use in Europe and Canada. As a result turfgrass managers must rely on cultural methods to manage moss encroachment. A survey of 15 golf courses in southwestern Ontario positively identified silvery thread moss (Bryum argenteum Hedw.) (STM) as the primary species of moss present. In order to determine the effects of irrigation practices on STM establishment two independent greenhouse experiments were conducted in which the quantity and frequency of irrigation were altered. Pots containing creeping bentgrass were inoculated with STM and irrigated at either 75% or 100% open pan evaporation (Eo) and at 1-, 2-, 4-, or7-day intervals. Volumetric water content was measured in the top 5.7 cm of the pots to confirm that changes in water availability were a result of irrigation practices. Between the two levels tested, irrigation quantity had no effect on the presence of STM. In the first experiment irrigation at 1-day and 2-day intervals had significantly more STM invasion than irrigation at 4- and 7-day intervals. In the second experiment point quadrat counts showed that irrigating at both 1-day and 2-day intervals resulted in significantly more STM and that the most moss was observed with the daily irrigation regime. Root data were also collected to determine the effect of irrigation practices on root mass. The daily irrigation treatments in both experiments had reduced root mass although in the first experiment only the root mass below 12 cm was lower. In the second experiment the total root mass was highest for the 4-day irrigation interval with the 2- and 7-day intervals having intermediate root mass and daily irrigation resulting in the least. [ABSTRACT FROM PUBLISHER]

Dollar spot (DS) (Scierotinia homoeocarpa F.T. Bennett) is an important disease on golf course turfgrasses in the United States. The objective of this study was to elucidate disease reduction mechanisms related to lightweight rolling. Creeping bentgrass (Agrostis stolonifera L.) plots that were subjected to daily (5 d wk-1) rolling treatments (1x a.m., 1x p.m., 2x a.m.) showed significant DS reductions when compared with a nonrolled control. Treatments rolled in the afternoon (after dew and guttation fluid dissipated) exhibited similar area under disease progress curve (AUDPC) values as treatments rolled in the morning in 2008, 2009, and 2010. Both 1x rolling treatments resulted in significant DS reductions compared with the control in 2009 and 2010. The 2x d-1 treatment exhibited significantly less DS than the control in all years as well as significantly lower AUDPC values than both 1x rolling treatments in 2009 and 2010. Rolling 2x d1 improved turfgrass quality compared with all other treatments in each year of the study. All rolling treatments exhibited higher root zone volumetric water content (%VWC) compared with the control in 2010, and significant effects on %VWC were observed on individual dates among treatments. Results indicate previously unidentified effects of rolling on putting greens, including added physical and biological effects, which may be contributing to DS suppression. [ABSTRACT FROM AUTHOR]

Creeping bentgrass ( Agrostis stolonifera L.) is a versatile, cross-pollinated, temperate and perennial turfgrass species. It occurs naturally in a wide variety of habitats and is also cultivated on golf courses, bowling greens and tennis courts worldwide. Isozymes and amplified fragment length polymorphisms (AFLPs) have been used to determine genetic diversity, and restriction fragment length polymorphisms (RFLPs) and random amplified polymorphic DNA (RAPDs) were used to construct a genetic linkage map of this species. In the current report, we developed and characterized 215 unique genomic simple sequence repeat (SSR) markers in creeping bentgrass. The SSRs reported here are the first available markers in creeping bentgrass to date. Eight hundred and eighteen alleles were amplified by 215 SSR loci, an average of 3.72 alleles per locus. Fifty-nine per cent of those alleles segregated in a 1:1 Mendelian fashion ( P > 0.05). Twenty-two per cent had a distorted segregation ratio ( P ≤ 0.05). These SSR markers will be useful for assessing genetic diversity in creeping bentgrass and will be important for the development of genetic linkage maps and identifying quantitative trait loci. These markers could enhance breeding programmes by improving the efficiency of selection techniques. [ABSTRACT FROM AUTHOR]

Excessive organic matter (OM) accumulation in creeping bentgrass (Agrostis palustris Huds.) putting greens, and its restriction of permeability, is one of the most difficult problems in turfgrass management. In this transition zone study, we characterized temporal and spatial aspects of OM accumulation, in an attempt to assess the effectiveness of management and to begin to uncover the processes controlling C sequestration. Root zone samples were collected from sand-based putting greens at 49 golf courses of various ages, generating 212 individual observations. Organic matter accumulated hyperbolically over time in the top 2.5 cm; apparent critical levels of 40 g kg-1 were exceeded within 5 yr. At a depth of 2.5 to 7.6 cm, accumulation was much slower and linear over rime, and critical levels were not reached even after 20 yr. Oxygen levels were never depressed more than 15%, indicating that intensive management of the upper soil profile was successfully allowing gas exchange into the root zone. Carbon accumulated in the soil profile hyperbolically, reflecting changes in the large OM pool near the soil surface. The sequestration rate of 59 g m-2 yr-1 over 25 yr was less than that observed by others examining soil under benrgrass greens in different environments. The evidence indicates that OM and C accumulation are strongly influenced by increasing microbial degradation rates as turfgrass systems age. [ABSTRACT FROM AUTHOR]

Lack of winter hardiness is a limitation to the use of annual meadowgrass (Poa annua f. reptans) on golf course putting greens in northern climates. Our objectives were 1) to assess the tolerance of 13 selections of annual meadowgrass to simulated ice encasement (SIE) and pink snow mould (PSM, Microdochium nivale); 2) to determine if these tolerances were interrelated or related to plant concentrations of water soluble carbohydrates (WSC); and 3) to determine if tolerance to SIE can be associated with accumulation of toxic substances. Samples of the annual meadowgrass selections were taken from an experimental green at University Park, Pennsylvania, on four dates from 23 Nov. 2005 until 27 Mar. 2006. Samples of creeping bentgrass (Agrostis stolonifera L.) 'Penn A-4' were included for comparison in studies on SIE and WSC. Samples were vacuum-sealed in plastic bags at 1°C for SIE and inoculated with three isolates of M. nivale for PSM tolerance. Small, but significant, differences were found among annual meadowgrass selections after 23 days of SIE, but all selections were dead after 33 days. Significant differences were detected in foliar blighting after inoculation with M. nivale, regrowth relative to uninoculated control being three times higher in the most tolerant than in the most susceptible selections. In late November, two annual meadowgrass selections contained significantly more WSC than did creeping bentgrass, but this was not correlated with tolerance to SIE or PSM, which were also not interrelated. A separate experiment with increasing duration of SIE to one of the annual meadowgrass selections and 'Penn A-4' showed that the critical exposure periods were 25-30 and 42-47 days, respectively. The concentrations of the phytotoxic compounds butan-l-ol and ethyl butyrate were two- to three-times higher in annual meadowgrass than in creeping bentgrass. [ABSTRACT FROM AUTHOR]

Creeping bentgrass (Agrostis stolonifera L.) has received more study and use as golf course turf than velvet bentgrass (A. canina L.). The objective of two field trials, managed as putting green and fairway turf, was to evaluate the performance of creeping and velvet bentgrass in mixed swards with annual bluegrass (Poa annua var. reptans Hausskn.) when subjected to traffic stresses. The trials were initiated on a sandy loam (fine-loamy, mixed, mesic Typic Hapludult). Wear (no-wear and wear) and compaction (no- compaction and compaction) were applied in a factorial combination to 15 creeping or velvet bentgrasses. Turf quality, turf density, and bentgrass populations of cultivars were more susceptible to wear stress than compaction. Velvet bentgrass performed and resisted the spread of annual bluegrass better than most creeping bentgrasses. Cultivars that formed denser turf performed well in both trials; 'Vesper', '7001', and 'Penn A-4' had the best overall performance. Interactions indicated 'SR 7200', 'Penn G-2', and 'Providence' were susceptible to compaction. 'Pennlinks' and 'Penncross' were ineffective at maintaining desirable bentgrass populations particularly in the putting green trial. Management strategies that minimize wear damage may have a greater impact on turf quality and bentgrass populations in mixed stands than practices intended to manage compaction, particularly on well-drained soil. [ABSTRACT FROM AUTHOR]

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 dactyion (L.) Pers. x 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. [ABSTRACT FROM AUTHOR]

Dollar spot caused by Sclerotinia homoeocarpa F. T. Bennett is the most economically important turf disease on golf courses in North America. Dollar spot resistance in a creeping bentgrass cultivar would greatly reduce the frequency, costs, and environmental impacts of fungicide application. Little work has been done to understand the genetics of resistance to dollar spot in creeping bentgrass. Therefore, QTL analysis was used to determine the location, number and effects of genomic regions associated with dollar spot resistance in the field. To meet this objective, field inoculations using a single isolate were performed over 2 years and multiple locations using progeny of a full sib mapping population ‘549 × 372’. Dollar spot resistance seems to be inherited quantitatively and broad sense heritability for resistance was estimated to be 0.88. We have detected one QTL with large effect on linkage group 7.1 with LOD values ranging from 3.4 to 8.6 and explaining 14–36% of the phenotypic variance. Several smaller effect QTL specific to rating dates, locations and years were also detected. The association of the tightly linked markers with the LG 7.1 QTL based on 106 progeny was further examined by single marker analysis on all 697 progeny. The high significance of the QTL on LG 7.1 at a sample size of 697 ( P < 0.0001), along with its consistency across locations, years and ratings dates, indicated that it was stable over environments. Markers tightly linked to the QTL can be utilized for marker-assisted selection in future bentgrass breeding programs. [ABSTRACT FROM AUTHOR]

Agrotis ipsilon multiple nucleopolyhedrovirus (family Baculoviridae, genus Nucleopolyhedrovirus, AgipMNPV), a naturally occurring baculovirus, was found infecting black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), on central Kentucky golf courses. Laboratory, greenhouse, and field studies investigated the potential of AgipMNPV for managing black cutworms in turfgrass. The virus was highly active against first instars (LC50) = 73 occlusion bodies [OBs] per μl with 2-μl dose; 95% confidence intervals, 55-98). First instars that ingested a high lethal dose stopped feeding and died in 3-6 d as early second instars, whereas lethally infected fourth instars continued to feed and grow for 4-9 d until death. Sublethal doses consumed by third or fifth instars had little or no effect on subsequent developmental rate or pupal weight. Horizontal transmission of AgipMNPV in turfgrass plots was shown. Sprayed suspensions of AgipMNPV (5 × 108-6 × 109OB/s/m2) resulted in 75 to >93% lethal infection of third or fourth instars in field plots of fairway-height creeping bentgrass, Agrostis stolonifera (Huds.), and on a golf course putting green collar. Virus spray residues (7 × 109OBs/m2) allowed to weather on mowed and irrigated creeping bentgrass field plots significantly increased lethal infection of implanted larvae for at least 4 wk. This study, the first to evaluate a virus against a pest in turfgrass, suggests that AgipMNPV has potential as a preventive bioinsecticide targeting early instar black cutworms. Establishing a virus reservoir in the thatch and soil could suppress successive generations 1 that key pest on golf courses and Sport fields. [ABSTRACT FROM AUTHOR]

Creeping bentgrass (Agrostis stolonifera L.) is an important turfgrass species used extensively on golf courses. It is highly susceptible to the fungal pathogen Sclerotinia homoeocarpa F.T. Bennett, the causal agent of dollar spot disease. There is a wide range in degree of susceptibility among current cultivars, with a limited number that have improved resistance. Colonial bentgrass (A. capillaris L.), a related species, has good resistance to dollar spot. We have produced iuterspecific hybrids between creeping bentgrass and colonial bentgrass and field-tested them against dollar spot. Some of the hybrids had excellent dollar spot resistance, exhibiting essentially no disease symptoms. This is the first formal report of evaluation of interspecific hybrids between creeping bentgrass and colonial bentgrass for an agronomically important trait. The results presented here suggest that the use of interspecific hybrids may be a useful new approach in Agrostis breeding programs. [ABSTRACT FROM AUTHOR]

Creeping bentgrass (Agrostis stolonifera L.) golf greens are often shaded by trees and surrounded by shrubs or brush that restrict airflow. The objective of this study was to compare and independently evaluate turfgrass responses to light reduction and airflow restriction in 'L93' and 'SR1020' creeping bentgrass. Artificial structures (122 by 122 cm) were assembled from polyvinyl chloride (PVC), and covered with black, woven polyester shade cloth (80% light reduction) to provide treatment effects. Shade cloth was applied to the structures to reduce irradiance and allow airflow or reduce airflow and allow irradiance. Plots were rated monthly for canopy, soil, and air temperature, visual color, density, and disease, soil moisture, root mass, and root glucose and fructose. Canopy and soil temperatures were lower in shade than in airflow restriction and uncovered, unsurrounded control turf. Canopy temperature was higher in airflow restriction than control but soil temperatures did not differ. Both shade and airflow restriction had a negative effect on turf color in L93. Airflow restriction caused a greater reduction in mean color rating than shade in SR1020 but shade color did not differ from control. Turf density declined in both cultivars due to both airflow restriction and shade compared with control. Air restriction reduced density more than shade in SR1020 but not in L93. The severity of brown patch (caused by Rhizoctonia solani Kühn) and dollar spot (caused by Sclerotinia homoeocarpa F.T. Bennett) in shade was less than in airflow restriction in both cultivars and less than control in SR1020. Soil moisture did not differ among treatments. Root mass was affected by both shade and airflow restriction in both cultivars and declined more rapidly in shade than in airflow restriction. Root glucose and fructose were not significantly affected by treatments. [ABSTRACT FROM AUTHOR]

The article focuses on a study on the development, characteristics and uses of Alpha and T-1 creeping bentgrass. It states that the objective in breeding the said cultivars was to compete more effectively with annual bluegrass under golf conditions. The two sources of the origins of Alpha and T-1 are presented. Common characteristics of the cultivars are discussed. The results of the study are also presented.

Reports that the genetically modified (GM) creeping bentgrass used for golf courses in North America can cross-pollinate wild grasses, according to a study conducted by a team in the U.S. Environmental Protection Agency in 2004. Reasons behind the use of GM grass; Actions taken by the government to counter gene flow; Comments from David Gardner, a bentgrass expert at Ohio State University's department of horticulture and crop science in Columbus, regarding the production of pollen by the grass on a golf course.