Chlelated Iron and Adjuvants Influence Bispyribac–Sodium Efficacy for Annual Bluegrass (Poa annua) Control in Cool-Season Turfgrasses

Spray adjuvants may enhance bispyribac–sodium efficacy for annual bluegrass control but chelated iron may be needed to reduce potential turf discoloration. Field and laboratory experiments were conducted to investigate the influence of iron and adjuvants on bispyribac–sodium efficacy for annual bluegrass control in cool-season turf. In laboratory experiments,14C–bispyribac–sodium foliar absorption increased in four grasses by approximately 50 and 100% when applied with a nonionic surfactant and methylated seed oil, respectively, compared to the herbicide alone. Chelated iron did not reduce14C–bispyribac–sodium absorption. In field experiments, spray adjuvants enhanced annual bluegrass control from bispyribac–sodium at 37 g ai/ha but not at 74 g ai/ha. Iron did not reduce annual bluegrass control from bispyribac–sodium, with or without adjuvants, but mitigated creeping bentgrass discoloration for all treatments.

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Trinexapac-Ethyl Influences Bispyribac-Sodium Absorption and Efficacy for Annual Bluegrass (Poa annua) Control in Creeping Bentgrass (Agrostis stolonifera)

Weed Technology ◽

10.1614/wt-08-015.1 ◽

2010 ◽

Vol 24 (3) ◽

pp. 326-331 ◽

Cited By ~ 2

Author(s):

Patrick E. McCullough ◽

Stephen E. Hart

Keyword(s):

Laboratory Experiments ◽

Management Practices ◽

Field Experiments ◽

Creeping Bentgrass ◽

Agrostis Stolonifera ◽

Sodium Absorption ◽

Dollar Spot ◽

Cool Season ◽

Annual Bluegrass ◽

Wettable Powder

Bispyribac-sodium selectively controls annual bluegrass in cool-season turf but efficacy may be influenced by management practices, such as plant growth regulator use. Experiments were conducted in New Jersey to investigate efficacy and absorption of bispyribac-sodium applied with trinexapac-ethyl for annual bluegrass control and turfgrass tolerance. In laboratory experiments with annual bluegrass, creeping bentgrass, and perennial ryegrass, tank-mixing trinexapac-ethyl with14C-bispyribac-sodium increased presumed foliar absorption of14C-bispyribac-sodium compared with nontrinexapac-ethyl treated; absorption increased with trinexapac-ethyl rate. Differences in14C-bispyribac-sodium absorption were not detected among emulsifiable concentration, microencapsulated concentration, and wettable powder trinexapac-ethyl formulations. In field experiments, sequential bispyribac-sodium applications controlled annual bluegrass 93%, but trinexapac-ethyl did not affect efficacy. Tank-mixing all trinexapac-ethyl formulations with bispyribac-sodium provided similar annual bluegrass control and creeping bentgrass quality compared with bispyribac-sodium alone. Applications of bispyribac-sodium reduced dollar spot cover in both years, whereas trinexapac-ethyl reduced dollar spot cover only in 2005.

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Selectivity of Methiozolin for Annual Bluegrass (Poa annua) Control in Creeping Bentgrass as Influenced by Temperature and Application Timing

Weed Science ◽

10.1614/ws-d-12-00135.1 ◽

2013 ◽

Vol 61 (2) ◽

pp. 209-216 ◽

Cited By ~ 18

Author(s):

Patrick E. McCullough ◽

Diego Gómez de Barreda ◽

Jialin Yu

Keyword(s):

Initial Treatment ◽

Laboratory Experiments ◽

Field Experiments ◽

Creeping Bentgrass ◽

Poa Annua ◽

Poor Control ◽

Application Timing ◽

Foliar Absorption ◽

Annual Bluegrass ◽

Treated Leaf

Methiozolin controls annual bluegrass in creeping bentgrass but application timing and temperature could influence efficacy in turf. In field experiments, sequential methiozolin applications totaling 3.36 kg ai ha−1provided excellent (> 90%) annual bluegrass control at 8 wk after initial treatment when treatments were initiated in February/March or May but programs totaling 0.84 and 1.68 kg ha−1provided poor control (< 70%) at both timings. Methiozolin at all rates caused minimal turf injury (< 8%) but creeping bentgrass was only injured from February/March applications. In growth chamber experiments, creeping bentgrass injury from methiozolin at 10 C was 2 and 4 times greater than at 20 C and 30 C, respectively, while annual bluegrass injury was similar across temperatures. In laboratory experiments, annual bluegrass had more foliar absorption of14C-methiozolin than creeping bentgrass at 30/25 C (day/night), compared to 15/10 C, but translocation was similar at both temperatures as > 90% of absorbed14C remained in the treated leaf after 72 h. Annual bluegrass distributed and recovered more radioactivity to shoots from root-applied14C-methiozolin than creeping bentgrass while both species had about 2 times more distribution to shoots at 30/25 C than 15/10 C. Metabolites were not detected in annual bluegrass or creeping bentgrass at 1, 3, or 7 d after treatment when grown at 15/10 C or 30/25 C suggesting uptake and translocation contributes to methiozolin selectivity in turfgrass.

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Absorption, Translocation, and Metabolism of Amicarbazone in Annual Bluegrass (Poa annua), Creeping Bentgrass (Agrostis stolonifera), and Tall Fescue (Festuca arundinacea)

Weed Science ◽

10.1614/ws-d-12-00136.1 ◽

2013 ◽

Vol 61 (2) ◽

pp. 217-221 ◽

Cited By ~ 15

Author(s):

Jialin Yu ◽

Patrick E. McCullough ◽

William K. Vencill

Keyword(s):

Tall Fescue ◽

Festuca Arundinacea ◽

Creeping Bentgrass ◽

Agrostis Stolonifera ◽

Poa Annua ◽

Physiological Effects ◽

Cool Season ◽

Foliar Absorption ◽

Annual Bluegrass

Amicarbazone controls annual bluegrass in cool-season turfgrasses but physiological effects that influence selectivity have received limited investigation. The objective of this research was to evaluate uptake, translocation, and metabolism of amicarbazone in these species. Annual bluegrass, creeping bentgrass, and tall fescue required < 3, 56, and 35 h to reach 50% foliar absorption, respectively. At 72 h after treatment (HAT), annual bluegrass and creeping bentgrass translocated 73 and 70% of root-absorbed14C to shoots, respectively, while tall fescue only distributed 55%. Annual bluegrass recovered ≈ 50% more root-absorbed14C in shoots than creeping bentgrass and tall fescue. Creeping bentgrass and tall fescue metabolism of amicarbazone was ≈ 2-fold greater than annual bluegrass from 1 to 7 d after treatment (DAT). Results suggest greater absorption, more distribution, and less metabolism of amicarbazone in annual bluegrass, compared to creeping bentgrass and tall fescue, could be attributed to selectivity of POST applications.

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Creeping Bentgrass (Agrostis stolonifera) Putting Green Tolerance to Bispyribac-Sodium

Weed Technology ◽

10.1614/wt-09-005.1 ◽

2009 ◽

Vol 23 (3) ◽

pp. 425-430 ◽

Cited By ~ 2

Author(s):

Patrick E. McCullough ◽

Stephen E. Hart

Keyword(s):

Growth Inhibition ◽

Field Experiments ◽

Creeping Bentgrass ◽

Agrostis Stolonifera ◽

Root Weight ◽

Putting Greens ◽

Annual Bluegrass ◽

Greenhouse Experiments ◽

Chelated Iron ◽

Putting Green

Bispyribac-sodium is an efficacious herbicide for annual bluegrass control in creeping bentgrass fairways, but turf tolerance and growth inhibition may be exacerbated by low mowing heights on putting greens. We conducted field and greenhouse experiments to investigate creeping bentgrass putting green tolerance to bispyribac-sodium. In greenhouse experiments, creeping bentgrass discoloration from bispyribac-sodium was exacerbated by reductions in mowing height from 24 to 3 mm, but mowing height did not influence clipping yields or root weight. In field experiments, discoloration of creeping bentgrass putting greens was greatest from applications of 37 g/ha every 10 d, compared to 74, 111, or 222 g/ha applied less frequently. Chelated iron effectively reduced discoloration of creeping bentgrass putting greens from bispyribac-sodium while trinexapac-ethyl inconsistently reduced these effects. Overall, creeping bentgrass putting greens appear more sensitive to bispyribac-sodium than higher mowed turf, but chelated iron and trinexapac-ethyl could reduce discoloration.

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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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Foliar and Root Absorption and Translocation of Bispyribac-sodium in Cool-season Turfgrass

Weed Technology ◽

10.1614/wt-05-155.1 ◽

2006 ◽

Vol 20 (4) ◽

pp. 1015-1022 ◽

Cited By ~ 27

Author(s):

Darren W. Lycan ◽

Stephen E. Hart

Keyword(s):

Creeping Bentgrass ◽

Dry Weight ◽

Total Activity ◽

Kentucky Bluegrass ◽

Cool Season ◽

Foliar Absorption ◽

Annual Bluegrass ◽

Shoot Dry Weight ◽

Root Absorption ◽

Sodium Tolerance

Response of creeping bentgrass, annual bluegrass, and Kentucky bluegrass to foliar, soil, or foliar plus soil applications of bispyribac-sodium was evaluated in greenhouse studies. Soil-alone and foliar plus soil applications of bispyribac-sodium at 148 or 296 g ai/ha resulted in greater injury and shoot dry weight reduction of all species 28 d after treatment (DAT) compared to foliar-alone treatments. Creeping bentgrass was less injured than annual or Kentucky bluegrass regardless of application placement. Further studies evaluated foliar and root absorption and translocation of14C-bispyribac-sodium in creeping bentgrass, annual bluegrass, Kentucky bluegrass, and roughtstalk bluegrass. Foliar absorption into creeping bentgrass was less than that of other species at most harvest timings from 4 to 72 h after treatment. Annual and roughstalk bluegrass translocated greater amounts of foliar-absorbed14C to the crown and shoots compared to creeping bentgrass. Annual and roughstalk bluegrass accumulated approximately 47% more14C per dry weight of plant tissue than creeping bentgrass and 74% more than Kentucky bluegrass after 72 h in nutrient solution containing14C-bispyribac-sodium. Annual and roughstalk bluegrass translocated approximately 80% of root-absorbed14C to shoots, whereas creeping bentgrass and Kentucky bluegrass translocated slightly less (66% of absorbed for both species). These studies suggest that bispyribac-sodium is readily absorbed by roots and translocated to shoots which may contribute to its total activity within a plant. In addition, creeping bentgrass displayed lower amounts of foliar and root absorption and subsequent translocation than annual and roughstalk bluegrass which may contribute to greater bispyribac-sodium tolerance displayed by creeping bentgrass.

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Nitrogen Influences Bispyribac-Sodium Efficacy and Metabolism in Annual Bluegrass (Poa annua) and Creeping Bentgrass (Agrostis stolonifera)

Weed Technology ◽

10.1614/wt-d-10-00136.1 ◽

2011 ◽

Vol 25 (3) ◽

pp. 385-390

Author(s):

Patrick E. McCullough ◽

Stephen E. Hart ◽

Thomas Gianfagna ◽

Fabio Chaves

Keyword(s):

Nitrogen Fertilization ◽

Laboratory Experiments ◽

Field Experiments ◽

Creeping Bentgrass ◽

Agrostis Stolonifera ◽

Poa Annua ◽

Annual Bluegrass ◽

Increased Sensitivity ◽

Sodium Metabolism ◽

Nitrogen Treatments

Field and laboratory experiments were conducted in New Jersey to investigate the influence of nitrogen on annual bluegrass and creeping bentgrass metabolism and responses to bispyribac-sodium. In field experiments, withholding nitrogen during the test period increased sensitivity of both grasses to bispyribac-sodium, and grasses fertilized biweekly had darker color on most rating dates. Nitrogen generally increased annual bluegrass tolerance to bispyribac-sodium at 74 g ha−1but not at 148 g ha−1. Creeping bentgrass was influenced by nitrogen at both herbicide rates. In laboratory experiments, weekly nitrogen treatments increased14C-bispyribac-sodium metabolism in both grasses compared to unfertilized plants. Annual bluegrass metabolized approximately 50% less herbicide regardless of nitrogen regime compared to creeping bentgrass. Overall, routine nitrogen fertilization appears to improve annual bluegrass and creeping bentgrass tolerance to bispyribac-sodium, which may be attributed to higher metabolism.

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Amicarbazone Efficacy on Annual Bluegrass and Safety on Cool-Season Turfgrasses

Weed Technology ◽

10.1614/wt-d-10-00036.1 ◽

2010 ◽

Vol 24 (4) ◽

pp. 461-470 ◽

Cited By ~ 20

Author(s):

Patrick E. McCullough ◽

Stephen E. Hart ◽

Dan Weisenberger ◽

Zachary J. Reicher

Keyword(s):

New Jersey ◽

Perennial Ryegrass ◽

Field Experiments ◽

Creeping Bentgrass ◽

Kentucky Bluegrass ◽

Growth Chamber ◽

Cool Season ◽

Influence Of Temperature ◽

Annual Bluegrass ◽

Influence Of Temperature On

Amicarbazone has potential for selective annual bluegrass control in cool-season turfgrasses, but seasonal application timings may influence efficacy. To test this hypothesis, field experiments in New Jersey and Indiana investigated amicarbazone efficacy from fall or spring applications and growth chamber experiments investigated the influence of temperature on efficacy. Fall treatments were more injurious to creeping bentgrass and Kentucky bluegrass than spring applications, but fall applications were also more efficacious for annual bluegrass control. In growth chamber experiments, injury and clipping weight reductions were exacerbated by increased temperatures from 10 to 30 C on annual bluegrass, creeping bentgrass, Kentucky bluegrass, and perennial ryegrass. Results suggest that amicarbazone use for annual bluegrass control in cool-season turf may be limited to spring applications, but increased temperature enhances activity on all grasses.

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Efficacy of the Bioherbicide Thaxtomin A on Smooth Crabgrass and Annual Bluegrass and Safety in Cool-Season Turfgrasses

Weed Technology ◽

10.1614/wt-d-15-00158.1 ◽

2016 ◽

Vol 30 (3) ◽

pp. 733-742 ◽

Cited By ~ 1

Author(s):

Joseph C. Wolfe ◽

Joseph C. Neal ◽

Christopher D. Harlow ◽

Travis W. Gannon

Keyword(s):

Perennial Ryegrass ◽

Tall Fescue ◽

Management Practices ◽

Field Experiments ◽

Creeping Bentgrass ◽

Cool Season ◽

Annual Bluegrass ◽

Thaxtomin A ◽

Initial Application ◽

Industry Standard

Recent trends favoring organic and sustainable turfgrass management practices have led to an increased desire for biologically based alternatives to traditional synthetic herbicides. Thaxtomin A, produced by the bacteriumStreptomyces scabies, has been reported to have PRE efficacy on broadleaf weeds, but efficacy of thaxtomin A on annual grassy weeds and safety to newly seeded cool-season turfgrasses have not been reported. Field experiments were conducted to evaluate PRE efficacy of thaxtomin A on smooth crabgrass and annual bluegrass. Monthly applications of thaxtomin A from April to July controlled smooth crabgrass through July but did not provide season-long control equivalent to an industry standard PRE herbicide. An initial application of thaxtomin A at 380 g ai ha−1followed by two applications at 190 or 380 g ha−1at 4-wk intervals provided season-long annual bluegrass control similar to an industry standard PRE herbicide. At 380 g ha−1, thaxtomin A reduced tall fescue and perennial ryegrass cover when applied 1 wk before seeding, at seeding, or 1 wk after seeding but was safe at other application timings. Up to three applications of thaxtomin A at 380 g ha−1at 4-wk intervals did not reduce perennial ryegrass cover. Applications to creeping bentgrass resulted in unacceptable turfgrass injury. These results suggest that thaxtomin A can suppress annual grassy weeds in tall fescue or perennial ryegrass turf when applied at least 2 wk before or after seeding. Furthermore, repeated applications of thaxtomin A can provide effective PRE control of annual bluegrass during overseeded perennial ryegrass establishment.

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Cool-Season Turfgrass Reseeding Intervals for Methiozolin

Weed Technology ◽

10.1614/wt-d-12-00092.1 ◽

2012 ◽

Vol 26 (4) ◽

pp. 789-792 ◽

Cited By ~ 4

Author(s):

Patrick E. McCullough ◽

Diego Gómez De Barreda

Keyword(s):

Perennial Ryegrass ◽

Tall Fescue ◽

Field Experiments ◽

Creeping Bentgrass ◽

High Rate ◽

Cool Season ◽

Application Timing ◽

Annual Bluegrass ◽

Turfgrass Establishment

Methiozolin selectively controls annual bluegrass in cool-season turfgrasses, and practitioners may wish to reseed desirable species in treated areas. Field experiments were conducted to evaluate reseeding intervals for creeping bentgrass, perennial ryegrass, and tall fescue following methiozolin applications. Turfgrass establishment varied for species, application timing (0, 2, 4, or 6 wk before seeding, WBS), and rates tested (0.56, 1.12, or 2.24 kg ai ha−1). Reductions in turf cover suggest that seeding of creeping bentgrass, perennial ryegrass, and tall fescue should be delayed 2 wk after methiozolin treatments at 0.56 kg ha−1. However, reseeding should be delayed after methiozolin treatments at 1.12 kg ha−1for approximately 4, 4, and 2 wk for creeping bentgrass, perennial ryegrass, and tall fescue, respectively. Similarly, establishment was reduced on all dates from the nontreated after 2.24 kg ha−1was applied at 4 WBS, suggesting that reseeding should be delayed for at least 6 wk on all three species at the high rate.

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