INFLUENCE OF MOWING ON LEAF AND TILLER ORIENTATION OF TURFGRASSES

Annual bluegrass (Poa annua L.) is a major grass weed on athletic fields. Since mowing modifies interspecies competitive ability, a program was initiated to determine if any morphological adaptations to mowing occur which might enable Kentucky bluegrass (Poa pratensis L.) to compete more successfully with annual bluegrass. Changes in leaf and tiller orientation of 11 Kentucky bluegrass cultivars and annual bluegrass in response to mowing or not mowing were measured. The mowing treatment consisted of clipping the grasses at 2, 3, 4 or 5 cm. For the 12 grasses there was a significant increase in leaf angle at the 2- and 3-cm mowing height. The increase was not consistent for all grasses and mowing treatments. Leaf angle was not related to the ability of the cultivars to compete with annual bluegrass. The grasses became more prostrate when mowed. While Kentucky bluegrass cultivars with the most prostrate growth habit have been shown to be more competitive with annual bluegrass, growth habit does not appear to be sufficiently important to be the main criterion for choosing Kentucky bluegrass cultivars for use in regularly irrigated, close clipped athletic fields.

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THE RESPONSE OF SOME KENTUCKY BLUEGRASS CULTIVARS TO COMPETITIVE STRESS FROM ANNUAL BLUEGRASS

Canadian Journal of Plant Science ◽

10.4141/cjps79-174 ◽

1979 ◽

Vol 59 (4) ◽

pp. 1123-1128

Author(s):

J. L. EGGENS

Keyword(s):

Competitive Ability ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Poa Annua ◽

Growth Chamber ◽

Annual Bluegrass ◽

Short Day

The ability of seven Kentucky bluegrass (Poa pratensis L.) cultivars to compete against annual bluegrass (Poa annua L.) under greenhouse and growth chamber conditions was evaluated. Under natural long days from June to November in the greenhouse and under a 15-h daylength in the growth chamber, annual bluegrass produced significantly more tillers than each of the Kentucky bluegrass cultivars. Under short day condition (10 h) in the growth chamber, the number of innovations produced by Sydsport Kentucky bluegrass was not significantly different from annual bluegrass. Under natural daylength of February and March in the greenhouse, the number of innovations produced by Baron, Glade and Sydsport Kentucky bluegrass cultivars was not significantly different from that produced by annual bluegrass. A method to evaluate the competitive ability of Kentucky bluegrass under daily 2-cm mowing height is described.

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SELECTIVE CONTROL OF ANNUAL BLUEGRASS IN KENTUCKY BLUEGRASS TURF WITH LINURON

Canadian Journal of Plant Science ◽

10.4141/cjps79-072 ◽

1979 ◽

Vol 59 (2) ◽

pp. 469-473 ◽

Cited By ~ 1

Author(s):

R. G. INGRATTA ◽

G. R. STEPHENSON ◽

C. M. SWITZER

Keyword(s):

Temperature Regime ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Controlled Environment ◽

Night Temperature ◽

Annual Bluegrass ◽

Selective Control ◽

Excellent Control

Optimum top growth of annual bluegrass (Pao annua L.) and Kentucky bluegrass (Poa pratensis L.) was obtained at 24/12 °C day/night temperature regime in controlled environment studies. The tolerance of seedling Kentucky bluegrass to linuron [3-(3,4-dichlorophenyl)-1)methylurea] appeared to be greatest at this temperature regime when photoperiods were 16 h in length. A granular formulation of linuron gave excellent control of annual bluegrass in Kentucky bluegrass turf at 6.7 kg/ha when applied postemergence. At this rate, all culitivars of Kentucky bluegrass tested, with the exception of Fylking, were tolerant to linuron as a granular formulation. After application of linuron at 3.4–6.7 kg/ha, phytotoxic residues remained in the soil at sufficient levels to injure seedling Kentucky bluegrass for up to 3 mo.

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Control of Annual Bluegrass (Poa annua) in Kentucky Bluegrass (Poa pratensis) Turf with Linuron

Weed Technology ◽

10.1017/s0890037x0003637x ◽

1992 ◽

Vol 6 (4) ◽

pp. 852-857 ◽

Cited By ~ 10

Author(s):

J. Christopher Hall ◽

C. Ken Carey

Keyword(s):

Field Experiments ◽

Poa Pratensis ◽

Stand Density ◽

Normal Growth ◽

Dry Weight ◽

Kentucky Bluegrass ◽

Controlled Environment ◽

Annual Bluegrass ◽

Turf Quality ◽

Severe Reduction

Effects of linuron on annual bluegrass control and Kentucky bluegrass cultivar tolerance were studied in field and growth chamber experiments. In controlled environment experiments, linuron at 0.06, 0.12, 0.25, 0.50, and 0.75 kg ai ha-1 was applied to pure stands of annual bluegrass and eight Kentucky bluegrass cultivars. Linuron at the two highest rates controlled annual bluegrass, reducing the clipping dry weight by more than 85% 4 wk after treatment, and by 65 to 92% 6 wk after treatment. Growth of Kentucky bluegrass was reduced with the most severe reduction occurring 2 wk after linuron application. All cultivars exhibited normal growth 8 wk after treatment. In field experiments, linuron at rates from 1.5 to 2.0 kg ai ha-1 controlled annual bluegrass in old (> 5 yr) Kentucky bluegrass stands, and in 16 cultivars of 1-yr and 2-yr-old Kentucky bluegrass stands, with little or no damage. At rates of 1.5, 2.0, and 2.5 kg ai ha-1 linuron, damage to newly seeded cultivars was moderate to severe. However, 6 to 7 wk after linuron application to newly seeded cultivars, stand density and turf quality were equivalent to untreated checks.

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Growth Habit Determination of Genotypes of African Bermudagrass

HortScience ◽

10.21273/hortsci.42.7.1513 ◽

2007 ◽

Vol 42 (7) ◽

pp. 1513-1516 ◽

Cited By ~ 1

Author(s):

Kevin E. Kenworthy ◽

Dennis L. Martin ◽

Charles M. Taliaferro

Keyword(s):

Growth Habit ◽

Leaf Angle ◽

Angle Measurements ◽

The Common ◽

Cynodon Transvaalensis ◽

Growth Habits ◽

Common Bermudagrass ◽

Prostrate Growth

Six African bermudagrass (Cynodon transvaalensis Burtt-Davy) genotypes, one common bermudagrass [C. dactylon (L.) Pers. var. dactylon] genotype, and ‘Tifway’ (C. dactylon × transvaalensis) hybrid bermudagrass were evaluated for shoot type, leaf angle, and shoot angle. Evaluations were conducted to determine if these measurements could be used to differentiate among upright, intermediate, and prostrate growth habits. Significant differences were found for all three techniques, but attempts to group plants together as having prostrate, intermediate, or upright growth habits was not possible. ‘Tifway’ was intermediate between the African bermudagrass genotypes and the common genotype for shoot type observations, but was more similar to upright-growing African bermudagrass for leaf angle and the more prostrate-growing common bermudagrass for shoot angle. Quantification of shoot type and leaf angle did not appear as useful as shoot angle measurements for screening germplasm to identify upright or prostrate growth habits in bermudagrass.

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Use of Prodiamine as a Preemergence Herbicide to Control Annual Bluegrass in Kentucky Bluegrass

HortTechnology ◽

10.21273/horttech.9.1.131c ◽

1999 ◽

Vol 9 (1) ◽

pp. 131c-132

Author(s):

Peter H. Dernoeden

Keyword(s):

Poa Pratensis ◽

Kentucky Bluegrass ◽

Golf Course ◽

Golf Courses ◽

Atlantic Region ◽

Control Data ◽

Annual Bluegrass ◽

Germination Period ◽

Mature Stand ◽

Preemergence Herbicides

Annual bluegrass (Poa annua L.) is an intractable weed problem on golf courses. Much has been written about annual bluegrass, but there is little documentation of regional germination period(s) and the proper timing of preemergence herbicides targeted for the control of the annual biotype (P. annua ssp. annua [L.] Timm. = AB). The objectives of this field study were to determine the optimum prodiamine rate and timing for effective AB control. The turf was a mature stand of `Kenblue' Kentucky bluegrass (Poa pratensis L.) maintained under conditions similar to those imposed for golf course roughs. Three rates of prodiamine (0.36, 0.73, and 1.1 kg·ha-1) were applied on three dates in 1995 (11 Aug., 14 Sept., and 13 Oct.) and 1996 (29 Aug., 16 and 30 Sept.). All rates applied 11 Aug. or 14 Sept. 1995, and 29 Aug. or 16 Sept. 1996 effectively controlled AB. None of the rates applied 13 Oct. 1995 reduced AB cover, and the 0.36 kg·ha-1 rate applied 30 Sept. 1996 provided relatively poor AB control. Data and observations indicated that the major germination period for AB was between late September and early December. Effective AB control was achieved whenever prodiamine, regardless of rate, was applied between mid-August and mid-September. These prodiamine rates and this application window may be effective only in relatively high cut turf (i.e., >5.0 cm) in the mid-Atlantic region. Chemical names used: O,O-bis(1-methylethyl) S-{2-[(phenylsulfonyl)amino]ethyl} phosphorodithioate (bensulide); N3,N3-di-n-propyl-2,4-dinitro-6-(trifluoromethyl)-m-phenylenediamine (prodiamine).

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Cool-season Turfgrass Response to Bispyribac-Sodium

HortScience ◽

10.21273/hortsci.40.5.1552 ◽

2005 ◽

Vol 40 (5) ◽

pp. 1552-1555 ◽

Cited By ~ 19

Author(s):

Darren W. Lycan ◽

Stephen E. Hart

Keyword(s):

Perennial Ryegrass ◽

Tall Fescue ◽

Field Experiments ◽

Poa Pratensis ◽

Creeping Bentgrass ◽

Kentucky Bluegrass ◽

Cool Season ◽

Severe Stunting ◽

Annual Bluegrass ◽

Fine Fescue

Previous research has demonstrated that bispyribac-sodium can selectively control established annual bluegrass (Poa annua L.) in creeping bentgrass (Agrostis stolonifera L.). Annual bluegrass is also a problematic weed in other cool-season turfgrass species. However, the relative tolerance of other cool-season turfgrass species to bispyribac is not known. Field experiments were conducted at Adelphia, N.J., in 2002 and 2003 to gain understanding of the phytotoxic effects that bispyribac may have on kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea (L.) Schreb.), and chewings fine fescue (Festuca rubra L. subsp. commutata Gaud.). Single applications of bispyribac at 37 to 296 g·ha–1 were applied to mature stands of each species on 11 June, 2002 and 10 June, 2003. Visual injury was evaluated and clippings were collected 35 and 70 days after treatment (DAT). Visual injury at 35 DAT increased as bispyribac rate increased. Kentucky bluegrass was least tolerant to bispyribac with up to 28% injury when applied at 296 g·ha–1. Injury on other species did not exceed 20%. Initial injury on perennial ryegrass, tall fescue, and chewings fine fescue was primarily in the form of chlorosis, while kentucky bluegrass exhibited more severe stunting and thinning symptoms. Bispyribac at rates from 74 to 296 g·ha–1 reduced kentucky bluegrass clipping weights by 19% to 35%, respectively, as compared to the untreated control at 35 DAT in 2002. Initial visual injury on perennial ryegrass, tall fescue, and chewings fine fescue dissipated to ≤5% by 70 DAT. However, recovery of kentucky bluegrass was less complete. These studies suggest that bispyribac-sodium has potential to severely injure kentucky bluegrass. Injury on perennial ryegrass, tall fescue, and chewings fine fescue appears to be less severe and persistent; therefore, bispyribac can be used for weed control in these species. Chemical names used: 2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoic acid (bispyribac-sodium).

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Role of Endothall in the Control of Annual Bluegrass in Turf

Weed Science ◽

10.1017/s0043174500078759 ◽

1972 ◽

Vol 20 (6) ◽

pp. 562-565 ◽

Cited By ~ 4

Author(s):

A. J. Turgeon ◽

W. F. Meggitt ◽

Donald Penner

Keyword(s):

Poa Pratensis ◽

Organic Matter Content ◽

Creeping Bentgrass ◽

Kentucky Bluegrass ◽

Matter Content ◽

Sand Culture ◽

Annual Bluegrass ◽

Underlying Soil ◽

Sand Cultures

Endothall (7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid) was evaluated for controlling annual bluegrass(Poa annuaL.) infestations in Kentucky bluegrass(Poa pratensisL.) and creeping bentgrass(Agrostis stoloniferaL.) turfs. Growth of annual bluegrass was selectively suppressed by three applications of 0.6 kg/ha of endothall, two or three applications of 1.1 and 2.2 kg/ha, and one application of 4.5 kg/ha made to the single plant sand cultures. Field treatments were variable and seasonably dependent. Endothall selectively killed annual bluegrass when applied to roots in sand culture at a concentration of 2.7 × 10−4molar. A granular formulation of endothall provided selective control of annual bluegrass in field and greenhouse studies. High watering frequency prior to application, low organic matter content of the underlying soil, and predominance of the annual biotype of annual bluegrass enhanced the selective action at the lowest rates of endothall application.

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Postemergence Control of Annual Bluegrass with Mesotrione in Kentucky Bluegrass

HortScience ◽

10.21273/hortsci.47.4.522 ◽

2012 ◽

Vol 47 (4) ◽

pp. 522-526 ◽

Cited By ~ 8

Author(s):

Joshua J. Skelton ◽

William Sharp ◽

Bruce E. Branham

Keyword(s):

Environmental Conditions ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Field Trials ◽

Poa Annua ◽

Annual Bluegrass ◽

Air Temperatures ◽

Significant Application ◽

Levels Of Control

Six field trials were conducted in 2009 and 2010 to study postemergence control of annual bluegrass (Poa annua L. var. Hausskn Timm) in kentucky bluegrass (Poa pratensis L.) with mesotrione. Mesotrione was applied at 11 different rate and application intervals to an area of kentucky bluegrass that was naturally infested with annual bluegrass. Mesotrione rates of 56 g·ha−1 applied two or three times per week for a total of 10 applications or 84 g·ha−1 applied two times per week for a total of seven applications provided consistent control of annual bluegrass but required significant application labor and resulted in minor kentucky bluegrass injury. Other treatments that required fewer applications, 110 g·ha−1 applied twice per week for five applications or 186 g·ha−1 per week for three applications, also achieved high levels of control under high air temperatures, but control levels can vary significantly as temperatures fluctuate and seasons change. Mesotrione can successfully control annual bluegrass in kentucky bluegrass when frequent applications at low rates are applied or when environmental conditions are conducive to control.

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Competitive ability of cowpea genotypes with different growth habit

Weed Science ◽

10.1614/ws-06-011r.1 ◽

2006 ◽

Vol 54 (4) ◽

pp. 775-782 ◽

Cited By ~ 11

Author(s):

Guangyao Wang ◽

Milton E. McGiffen ◽

Jeff D. Ehlers ◽

Edilene C. S. Marchi

Keyword(s):

Growth Rate ◽

Competitive Ability ◽

Growth Habit ◽

Biomass Accumulation ◽

Growing Season ◽

Similar Reduction ◽

Relative Growth ◽

Use Efficiency ◽

Common Purslane ◽

Prostrate Growth

Growth habit is an important determinant of competitive ability in legume crops. Erect ‘Iron-Clay’ (IC), semi-erect ‘IT89KD-288’ (288), and prostrate ‘UCR 779’ (779) cowpea genotypes were planted with four densities of common sunflower or common purslane to determine which cowpea growth habit is more competitive to these weeds having markedly different statures. Both sunflower and purslane reduced cowpea relative growth rate (RGR) but at different phases of the growing season. Low-growing purslane had an effect in the earlier part of the season, and sunflower decreased cowpea RGR in the middle of growing season. RGR of genotype IC was the least affected and genotype 779 the most reduced by sunflower. Cowpea apparently compensated for early season purslane competition by increasing RGR after purslane flowering, with RGR for the IC genotype increasing the most and 779 increasing the least. All cowpea genotypes caused a similar reduction in sunflower biomass accumulation; but purslane biomass was most reduced by genotype IC and least affected by genotype 288. Erect genotype IC is more competitive due to its taller stature, greater height growth rate, and higher position of maximal leaf area density, despite a lower photosynthetic rate and light use efficiency than the other cowpea genotypes. Our results suggest that erect cowpea growth habit may be generally more competitive with weeds compared to semi-erect or prostrate growth habit.

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Response of Monocotyledons to BAS 9052 OH

Weed Science ◽

10.1017/s004317450005846x ◽

1984 ◽

Vol 32 (1) ◽

pp. 28-32 ◽

Cited By ~ 32

Author(s):

Hideo Hosaka ◽

Hideo Inaba ◽

Hisao Ishikawa

Keyword(s):

Festuca Arundinacea ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Tropical Species ◽

Festuca Rubra ◽

Subsequent Growth ◽

Meadow Fescue ◽

Annual Bluegrass ◽

Red Fescue ◽

Poa Trivialis

Postemergence applications of BAS 9052 OH, {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one}, at 0.25 and 0.5 kg ai/ha were made to 27 temperate and 28 tropical species ofGramineae. Annual bluegrass (Poa annuaL. ♯3POAAN) and rattail fescue (Festuca myurosL. ♯ VLPMY) were resistant to these rates of BAS 9052 OH. Five species of fescue and three species of bluegrass received postemergence applications of BAS 9052 OH at rates of 0.1 to 6.4 kg ai/ha. The germination of seeds and the subsequent growth of the seedlings of these species as influenced by various concentrations of BAS 9052 OH were also studied. Meadow fescue (Festuca pratensisHuds. ♯ FESPR), tall fescue (Festuca arundinaceaSchreb. ♯ FESAR), Kentucky bluegrass (Poa pratensisL. ♯ POAPR), and rough-stalked meadowgrass (Poa trivialisL. ♯ POATR) were most susceptible; annual bluegrass was somewhat less resistant; hard fescue (Festuca longifoliaThuill) was resistant; red fescue (Festuca rubraL. ♯ FESRU) and rattail fescue were very resistant.

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