Quantitative and qualitative responses of an established Kentucky bluegrass (Poa pratensis L.) turf to N, P, and K additions

Kentucky bluegrass is a common turf species used on golf courses, sports fields, municipal parks, sod farms, road banks, as well as residential and school yards. Our objective was to determine the effects of N, P, K rates on turfgrass quantitative response (clipping yield and underground turf biomass) and qualitative response (shoot density and foliage colour) under a continuous clipping removal. A 3-yr field study was conducted on two sites, a sand that met the specifications of the United States Golf Association (USGA) and a loam. The factorial experiment was arranged in a randomized complete block design with four replicates and different levels of three nutrients, N (0 or 50 to 300 kg ha-1 yr-1), P (0 or 21.8 to 87.3 kg P ha-1 yr-1), and K (0 or 41.7 to 250 kg K ha-1 yr-1). The maximum clipping yield was produced at the rate of 200 kg N ha-1 yr-1 in the loam and 300 kg N ha-1 yr-1 in the sand. Increasing N rates linearly reduced underground turf biomass. Added P and K had no effect on clipping yield and underground turf biomass. Nitrogen significantly improved shoot density and foliage colour. However, equivalent shoot density and colour ratings required 40 to 80 kg more N ha-1 yr-1 in the sand compared to the loam. Phosphorus and K had no significant effect on shoot density and colour in the loam. Colour response to P and K depended on N rates in the sand. Fertilizer units needed to increase soil test P averaged 6 kg added P ha-1 mg-1 PM-III kg-1 across soil types. To replenish soil K, 7 kg K ha-1 per mg KM-III kg-1 were required in the sand, and 3 kg K ha-1 per mg KM-III kg-1 in the loam. Phosphorus and K fertilizer programmes should account for P and K removals to maintain low to medium fertility levels for P, and medium for K when conditions are similar to those in this research. Key words: Turfgrass clipping yield, underground turf biomass, turfgrass shoot density, turfgrass foliage colour, Kentucky bluegrass fertilization

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Effect of leaf nitrogen concentration versus CND nutritional balance on shoot density and foliage colour of an established Kentucky bluegrass (Poa pratensis L.) turf

Canadian Journal of Plant Science ◽

10.4141/p05-242 ◽

2006 ◽

Vol 86 (4) ◽

pp. 1107-1118 ◽

Cited By ~ 5

Author(s):

Abdo Badra ◽

Léon-Étienne Parent ◽

Guy Allard ◽

Nicolas Tremblay ◽

Yves Desjardins ◽

...

Keyword(s):

Poa Pratensis ◽

Block Design ◽

Nitrogen Concentration ◽

Principal Component ◽

Kentucky Bluegrass ◽

Shoot Density ◽

Leaf Nitrogen ◽

N Concentration ◽

Randomized Block Design ◽

N Status

A 3-yr field study was conducted in a loam and a sand site to determine the effects of N, P, and K application rates on N status, shoot density and foliage colour of Kentucky bluegrass clippings and to derive critical N values. The experiment was arranged in a completely randomized block design with four replicates and three nutrients, N (0 or 50 to 300 kg ha-1 yr-1), P (0 or 21.8 to 87.3 kg P ha-1 yr-1), and K (0 or 41.7 to 250 kg K ha-1 yr-1), equally broadcast six times per growing season. We examined N concentration values, log-transformed N concentration values, and CND values for compositional nutrient simplexes comprising one (VN1), three (VN3), five (VN5), or 11 (VN11) macro- and micro-nutrients. Critical values for N expressions were obtained from linear relationships with targeted visual shoot density and foliage colour ratings that were closely related to each other (R2 = 0.92). The highest coefficients of determination (0.975 to 0.980) were obtained with VN5 and VN11. The VN5 values were consistent with literature data and across experimental sites, and were the most successful (99% success) in diagnosing N sufficiency in 328 qualified specimens from commercial sod farms. Compared with raw concentrations, the CND transformation reduced from 0.6 to 0.1 the degree of inter-correlation among nutrients in principal component analysis and was amenable to a χ2 distribution of CND indices. Using a critical imbalance index (CNDr2) of 5.6as χ2 value, and a critical CND IN2 index of 1.5 for a 5-nutrient simplex, we diagnosed as imbalanced 179 qualified specimens of which 110 specimens presented excessively high N level among the 328 qualified specimens in commercial stands. The proposed five-nutrient CND norms proved to be effective in diagnosing N status in Kentucky bluegrass clippings across experimental, literature, and survey data sets. Key words: Plant tissue nutrient diagnosis, DRIS, CND, Kentucky bluegrass nitrogen fertilization, turfgrass shoot density, turfgrass foliage colour

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First Report of Summer Patch of Kentucky Bluegrass Caused by Magnaporthe poae in Colorado

Plant Disease ◽

10.1094/pdis-91-11-1519a ◽

2007 ◽

Vol 91 (11) ◽

pp. 1519-1519 ◽

Cited By ~ 2

Author(s):

C. E. Swift ◽

A. Blessinger ◽

N. Brandt ◽

N. Tisserat

Keyword(s):

Poa Pratensis ◽

Rocky Mountain ◽

Kentucky Bluegrass ◽

The United States ◽

Mountain Region ◽

First Report ◽

Magnaporthe Poae ◽

Rocky Mountain Region ◽

Continental Divide ◽

Species Specific

The ectotrophic, root-infecting fungus Magnaporthe poae is the cause of summer patch of Kentucky bluegrass (Poa pratensis). The disease is widely distributed in the mid-Atlantic Region of the United States and west to central Nebraska and Kansas (2). It also has been found in certain locations of Washington and California (2) but has not been confirmed in the Rocky Mountain Region. In August 2005 and 2006, tan patches and rings of dead turf ranging from 10 to 30 cm in diameter were observed in Kentucky bluegrass swards in Grand Junction and Greeley, CO, respectively. The sites, separated by approximately 360 km, are located west and east of the Continental Divide. A network of ectotrophic hyphae were observed on diseased root segments collected from both sites. A fungus morphologically similar to M. poae (2) was consistently isolated from these segments. DNA was extracted from mycelium of one isolate from each location and amplified by PCR with the M. poae species-specific primers MP1 and MP2 (1). A 453-bp DNA fragment was consistently amplified from DNA of both isolates, diagnostic of M. poae. To our knowledge, this is the first report of summer patch in Colorado and indicates that M. poae may be widely distributed in the central Rocky Mountain Region. References: (1) T. E. Bunting et al. Phytopathology 86:398, 1996. (2) B. B. Clarke and A. B. Gould, eds. Turfgrass Patch Diseases Caused by Ectotrophic Root-Infecting Fungi. The American Phytopathological Society, St. Paul, MN, 1993.

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Variation within Poa Germplasm for Salinity Tolerance

HortScience ◽

10.21273/hortsci.44.6.1517 ◽

2009 ◽

Vol 44 (6) ◽

pp. 1517-1521 ◽

Cited By ~ 9

Author(s):

Joseph G. Robins ◽

B. Shaun Bushman ◽

Blair L. Waldron ◽

Paul G. Johnson

Keyword(s):

Water Resources ◽

Salinity Tolerance ◽

Perennial Ryegrass ◽

Tall Fescue ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

The United States ◽

Human Populations ◽

Wide Range ◽

Potential Part

As competition for water resources in areas of western North America intensify as a result of increasing human populations, the sustainability of turfgrass irrigation with limited water resources is questionable. A potential part of the solution is the use of recycled wastewater for landscape irrigation. However, as a result of high levels of salt, successful irrigation with recycled wastewater will likely need to be coupled with selection for increased salinity tolerance in turfgrass species. Additionally, salinity-tolerant turfgrass will allow production on soils with inherently high salt levels. The study described here characterized the relative salinity tolerance of 93 accessions of Poa germplasm from the USDA National Plant Germplasm System (NPGS). Control cultivars of tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire], perennial ryegrass (Lolium perenne L.), and kentucky bluegrass (Poa pratensis L.) were also evaluated for comparison. Kentucky bluegrass accessions exhibited a wide range of LD50 (salinity dosage necessary to kill 50% of plants) values from 811 ECdays (PI 369296 from Russia) to 1922 ECdays (PI 371768 from the United States). Five kentucky bluegrass accessions exhibited salinity tolerance equal to or better than that of the tall fescue (LD50 = 1815 ECdays) and perennial ryegrass (LD50 = 1754 ECdays) checks. Thus, there is sufficient variation within this species to develop bluegrass with substantially higher salinity tolerance.

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(140) Salt Tolerance Assessment of Kentucky Bluegrass Cultivars Selected for Drought Tolerance

HortScience ◽

10.21273/hortsci.41.4.1057c ◽

2006 ◽

Vol 41 (4) ◽

pp. 1057C-1057 ◽

Cited By ~ 1

Author(s):

Catherine M. Grieve ◽

Stacy A. Bonos ◽

James A. Poss

Keyword(s):

Salt Tolerance ◽

Drought Tolerance ◽

Growth Rates ◽

Poa Pratensis ◽

Block Design ◽

Kentucky Bluegrass ◽

Saline Control ◽

Drought Tolerant ◽

Area Expansion ◽

Poa Arachnifera

Six selections of Kentucky bluegrass (Poa pratensis L.) cultivars, selected based on their drought tolerance under field and growth chamber conditions in New Brunswick, N.J., were evaluated for salt tolerance based on yield and growth rates at eight soil water salinities [2 (control), 6, 8, 10, 12, 14, 18, and 22 dSm-1] from Apr. to Sept. 2005 in Riverside, Calif. Cultivars Baron and Brilliant were selected as drought sensitive and `Cabernet', `Eagleton', and `Midnight' were selected as drought tolerant. A Texas × Kentucky bluegrass (Poa arachnifera × Poa pratensis) hybrid selection (identified as A01-856) developed for improved drought and heat tolerance was also included. Vegetative clones were established in a randomized complete-block design with three replications, each containing 11 clones. Cumulative biomass and clone diameters were measured over time to evaluate relative yields and growth rates for the six cultivar selections. Based upon maximum absolute biomass production as a function of increasing EC, the order of production was `Baron' > `Brilliant' > `Eagleton' > `Cabernet' ≥ `Midnight' > A01-856. Yield relative to the non-saline control (2 dSm-1) for each cultivar was similar, except that the differences between cultivars were less pronounced, and `Baron' slightly outperformed `Brilliant'. Clone area expansion rates were analyzed with a phasic growth model and beta, the intrinsic growth rate of the exponential phase parameter, significantly varied with salinity. Ranking of cultivars, based on expansion rates, was similar to that based on cumulative biomass. Salinity tolerance in this experiment did not appear to be related to the observed ranking for drought tolerance.

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Effects of clipping and nitrogen fertilization on tiller development and flowering in Kentucky bluegrass

Canadian Journal of Plant Science ◽

10.4141/cjps93-077 ◽

1993 ◽

Vol 73 (2) ◽

pp. 569-575 ◽

Cited By ~ 8

Author(s):

D. J. Thompson ◽

K. W. Clark

Keyword(s):

Key Words ◽

Nitrogen Fertilization ◽

Poa Pratensis ◽

Cold Treatment ◽

Kentucky Bluegrass ◽

Shoot Density ◽

Stem Length ◽

Seed Harvest ◽

Seed Field

One hundred cores (10 × 10 × 12 cm) of Kentucky bluegrass (Poa pratensis L. ’Nugget’) were removed from an established seed field, potted, and subjected to two clipping treatments after seed harvest (clipping at 2.5 cm to simulate straw and mechanical stubble removal and clipping at 7.5 cm to simulate straw removal) and two fertilizer treatments (solutions with and without the equivalent of 100 kg ha−1 of N). The plants were then subjected to a cold treatment (98 d at 2.5 °C) to induce flowering. Added N increased the number of large tillers formed before the cold treatment, and produced similar increases in the number of initiated tillers and flowering shoots. Added N resulted in larger inflorescences with more spikelets. Close clipping (2.5 cm) did not affect tillering or flowering shoot density, but reduced stem length and resulted in smaller inflorescences with fewer spikelets. Key words: Kentucky bluegrass, nitrogen, clipping height, tillering and flowering

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(81) Fine Fescues and Shade Tolerance

HortScience ◽

10.21273/hortsci.40.4.1041a ◽

2005 ◽

Vol 40 (4) ◽

pp. 1041A-1041

Author(s):

Tara E. Paranick ◽

N. Suzanne Lang

Keyword(s):

Poa Pratensis ◽

Block Design ◽

Light Response ◽

Kentucky Bluegrass ◽

Potential Method ◽

State University ◽

Response Curves ◽

Red Fescue ◽

Light Response Curves ◽

The Impact

Shaded environments present major obstacles for establishing high quality, persistent, and resistant turfs. Exogenous fructose applications are being examined as a potential method to counteract the effects of shade on turf. This work examines the effectiveness of fructose applications under different light levels on two fine leaf fescue cultivars: chewings fescue (Festucarubra var. commutata) `SR5100' and creeping red fescue (Festucarubra var. rubra) `Dawson'. The experiment was conducted at Michigan State University, East Lansing, inside a simulated dome environment. The experiment was a randomized complete-block design that began 21 Oct. 2004 with two main factors: light and fructose. There were three light treatments: ambient light (shaded); supplemental high light; and supplemental low light. Fructose (0% or 1.25% weight/volume), dissolved in water with an organosilicone adjuvant, was applied once per week. Quality and color ratings, clippings, core samples, density, and leaf reflectance were recorded. In addition, light response curves (LRC) were taken inside an Econoair® growth chamber using a LI-COR-6400® on the fine fescues, kentucky bluegrass (Poa pratensis) `Cynthia', and bermudagrass (Cyondon dactylon) `Princess'. Preliminary results show that fructose had no significant effect in each light treatment for turf quality and color. However, fructose had a significant impact on clipping weights and density. The LRC specified the required and potential carbon needs as well as indicated the threshold levels, respectively, by species. The impact of fructose alone and in combination with supplemental light on photosynthesis efficiency will be presented.

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Turfgrass Species Affect the Establishment and Bloom of Kura Clover (Trifolium ambiguum) in Lawns

HortScience ◽

10.21273/hortsci13779-18 ◽

2019 ◽

Vol 54 (5) ◽

pp. 824-828 ◽

Cited By ~ 2

Author(s):

Ian Lane ◽

Eric Watkins ◽

Marla Spivak

Keyword(s):

Perennial Ryegrass ◽

Tall Fescue ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

The United States ◽

Urban Landscapes ◽

Seeding Rate ◽

Upper Midwest ◽

Trifolium Ambiguum ◽

Kura Clover

Lawns represent one of the largest cultivated areas in urban landscapes, and in the Upper Midwest of the United States, lawns are typically composed of a small number of cool-season turfgrass species. There is increased interest in enhancing areas dedicated to lawns using flowering species for conservation purposes—for example, to support pollinators. In this study we used a model flowering forb, Kura clover (Trifolium ambiguum M. Bieb.), because—like many flowering species of conservation interest—it is slow to establish and is sensitive to grass competition. We varied the Kura clover seeding rate into four different turfgrass species treatments: kentucky bluegrass (Poa pratensis L.), hard fescue (Festuca brevipila Tracy), tall fescue [Schedonorus arundinaceum (Schreb.) Darbysh.], and perennial ryegrass (Lolium perenne L.) in two separate trials. Establishment and bloom of Kura clover was significantly greater in trial 1 for kentucky bluegrass and hard fescue than tall fescue and perennial ryegrass. In trial 2, Kura clover established significantly greater in kentucky bluegrass compared with tall fescue and perennial ryegrass, whereas Kura establishment in hard fescue was not significantly different from the other treatments. The seeding rate of Kura clover did not affect establishment in either trial. The results from this study suggest kentucky bluegrass and hard fescue are promising turf companion grasses for future forb/turf interseeding research.

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Growth Responses of Hybrid Bluegrass and Tall Fescue as Influenced by Light Intensity and Trinexapac-ethyl

HortScience ◽

10.21273/hortsci.50.8.1241 ◽

2015 ◽

Vol 50 (8) ◽

pp. 1241-1247 ◽

Cited By ~ 2

Author(s):

Meghyn Meeks ◽

Ambika Chandra ◽

Ben G. Wherley

Keyword(s):

Tall Fescue ◽

Festuca Arundinacea ◽

Poa Pratensis ◽

Block Design ◽

Kentucky Bluegrass ◽

Late Spring ◽

Healthy Plant ◽

Growth Responses ◽

Leaf Elongation ◽

Turfgrass Quality

Interspecific hybrids between texas bluegrass (Poa arachnifera Torr.) and kentucky bluegrass (Poa pratensis L.) are known to exhibit good heat tolerance, which has aided in their adaptation to the warmer climates of the southern United States, but their tolerance to shade has not been investigated. The objectives of this study were to 1) evaluate the growth responses of interspecific bluegrass hybrids (P. arachnifera × P. pratensis) in comparison with kentucky bluegrasses and a shade-tolerant cultivar of tall fescue (Festuca arundinacea Schreb.) under full sunlight and shaded environments, 2) identify optimum times to evaluate shade tolerance using the selected growth measurements, 3) calculate the minimum daily light requirements to retain acceptable turfgrass quality, and 4) determine if trinexapac-ethyl (TE) applications enhance hybrid bluegrass quality under shade. Two 10-week greenhouse experiments (late spring and early fall) were conducted in Dallas, TX. Within each of three light environments a randomized complete block design was used to accommodate three replications of eight genotypes treated with and without TE (0 or 0.228 kg·ha−1 a.i.). Turfgrass quality, leaf elongation rates, clipping dry weights, and percent green cover were measured. Meaningful comparisons were best during the late spring when daily light integrals (DLI) were optimum for healthy plant growth. Shade-tolerant hybrid bluegrasses (DALBG 1201 and TAES 5654) were identified using turfgrass quality and leaf elongation rates. These genotypes exhibited above-acceptable turfgrass quality in all environments, and a reduced leaf elongation rate similar to the tested dwarf-type tall fescue. DLI requirements of DALBG 1201 and TAES 5654 were ≤4 to achieve acceptable quality. TE applications generally did not improve turfgrass quality of genotypes, although leaf elongation rates were significantly reduced in all environments.

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Eight Years of Herbicide and Nitrogen Fertilizer Treatments on Kentucky Bluegrass (Poa pratensis) Turf

Weed Science ◽

10.1017/s0043174500070818 ◽

1983 ◽

Vol 31 (6) ◽

pp. 825-831 ◽

Cited By ~ 17

Author(s):

J. Jack Murray ◽

Dayton L. Klingman ◽

Ralph G. Nash ◽

Edwin A. Woolson

Keyword(s):

Poa Pratensis ◽

Kentucky Bluegrass ◽

Annual Grass ◽

Percentage Cover ◽

Turf Quality ◽

Quality Ratings ◽

Quality Rating ◽

Common Dandelion ◽

N Rates ◽

Fertilizer Rates

Annual applications of three nitrogen (N) rates, two broadleaf herbicides, and six annual-grass herbicides in Kentucky bluegrass (Poa pratensisL.) turf were made from 1974 to 1981. With each increment increase in N (2, 4, and 6 kg N/200 m2), the percentage cover of crabgrass (Digitariaspp.) and number of common dandelion (Taraxacum officinaleWeber # TAROF) plants were reduced when compared with the next lower rate. There was an interaction between crabgrass control by the annual-grass herbicides and fertilizer rates. When highly effective herbicides were used, there were no differences in crabgrass control related to N rate. When less effective herbicides or no annual-grass herbicides were used, there were great changes directly related to N rate. Each increment of increased N rate increased the turf quality rating. The broadleaf herbicides resulted in differential quality ratings, although differences were relatively small. Highest quality ratings were for plots treated with the three most effective annual-grass herbicides. Residues in the ppb range of some herbicides were detected in soils sampled about a year after the eighth annual herbicide treatments, but residues were below the phytotoxic level and therefore would have had no effect on control of weeds.

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The Influence of Cow Age on Botanical Composition of Diets in Mountain Riparian Areas in Eastern Oregon of the United States

Sustainable Agriculture Research ◽

10.5539/sar.v3n1p1 ◽

2013 ◽

Vol 3 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Enkhjargal Darambazar ◽

Timothy DelCurto ◽

Daalkhaijav Damiran

Keyword(s):

Plant Species ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

The United States ◽

Botanical Composition ◽

Riparian Areas ◽

Western Wheatgrass

The objective of this study was to evaluate the effect of cow age on botanical composition of diets in mountain riparian areas. Treatments consisted of 30 first-calf heifers, and 30 mature cows randomly assigned to four pastures (2 pastures/treatment, average 21.5 ha) in a 2-year study with a cross-over design. Botanical composition of diets was determined in fecal samples obtained from 10 animals in each treatment (5 per pasture) on the fourth week of 35 to 42-days grazing periods using the microhistological technique. Crude protein (CP) content and in vitro dry matter digestibility (IVDMD) were determined, and correction factors were calculated for 22 major plant species. In digested samples, grasses were overestimated, whereas, all forbs but northern bedstraw (Galium boreale L.), were underestimated, and all shrub species were overestimated except common snowberry (Symphoricarpos albus L.). Ponderosa pine (Pinus ponderosa Dougl.) was highly overestimated after digestion. There was no difference between cattle age class in the total number of plant species found in the diets (p > 0.10) averaging in 41 species. Most individual grass and grasslike species made up more than 5% of the diets, while all individual forb, shrub, and tree species were minor components, not exceeding 5%, except ponderosa pine. Western wheatgrass (Agropyron smithii Rybd.) and tufted hairgrass (Deschampsia caespitosa (L.) Beauv.) accounted for over 10% of the diets. Heifers consumed more (p < 0.05) grasses and fewer (p < 0.10) shrubs and trees compared to mature cows. The diet of heifers contained more western wheatgrass, Baltic rush (Juncus balticus Willd.), and pinegrass (Calamagrostis rubescens Buckl.) (p < 0.10), but less Kentucky bluegrass (Poa pratensis L.) (p < 0.01), than the diet of mature cows. The proportion of ponderosa pine needles was higher in the diet of mature cows (p < 0.10), than in the diet of first calf heifers. In summary, mature cows appeared to have selected a diet that contained less grasses and more shrubs and trees compared to younger cows.

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