Seashore Paspalum Tolerance to Amicarbazone at Various Seasonal Application Timings

2015 ◽  
Vol 29 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Jialin Yu ◽  
Patrick E. McCullough ◽  
Mark A. Czarnota

Turfgrass injury from triazines has limited the use of photosystem II (PS II) inhibitors for weed control in seashore paspalum. Amicarbazone is a new PS II inhibitor with potential safety in seashore paspalum, but the effects of application timing on turf tolerance has received limited investigation. Field experiments were conducted in Griffin, GA to evaluate the tolerance of ‘Sea Isle 1’ seashore paspalum to amicarbazone applications in winter, spring, and summer. Seashore paspalum had minimal injury (< 5%) from amicarbazone treatments (98, 196, and 392 g ai ha−1) applied for annual bluegrass control in winter and spring. By 6 wk after treatment (WAT), amicarbazone at 392 g ha−1provided 78 and 90% annual bluegrass control in 2013 and 2014, respectively, and was similar to pronamide at 1,680 g ai ha−1. Amicarbazone at 196 g ha−1provided 71% control of annual bluegrass in 2014, but control was poor (< 70%) in 2013. Sequential amicarbazone applications at 98 g ha−1provided poor control in both years by 6 WAT. From six amicarbazone rates (up to 984 g ha−1) applied in summer, seashore paspalum required 510 and < 123 g ha−1for 20% turfgrass injury (I20) and 20% clipping reduction (CR20), respectively, whereas I20and CR20measured > 984 g ha−1for ‘Tifway’ bermudagrass. Overall, amicarbazone may be safely applied to seashore paspalum in winter, spring, and summer at rates and regimens evaluated. However, seashore paspalum may exhibit shoot growth inhibition up to 4 WAT, suggesting that end users should be cautious when using amicarbazone during active growth in summer.

Weed Science ◽  
2013 ◽  
Vol 61 (2) ◽  
pp. 209-216 ◽  
Author(s):  
Patrick E. McCullough ◽  
Diego Gómez de Barreda ◽  
Jialin Yu

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.


2013 ◽  
Vol 27 (3) ◽  
pp. 596-603 ◽  
Author(s):  
Matthew T. Elmore ◽  
James T. Brosnan ◽  
Gregory K. Breeden ◽  
Aaron J. Patton

Selective annual bluegrass (ABG) control with mesotrione is often inconsistent, and sequential applications might be required for complete control. The complementary nature ofp-hydroxyphenylpyruvate dioxygenase (HPPD)- and photosystem II (PSII)-inhibiting herbicides is well documented. The HPPD-inhibiting herbicide mesotrione and the PSII-inhibiting herbicide amicarbazone both have efficacy against annual bluegrass and safety on certain cool-season turfgrasses. Topramezone is a HPPD-inhibiting herbicide being investigated for use in turfgrass. Field and greenhouse experiments were conducted to examine single applications of topramezone and mesotrione alone or in combination with amicarbazone for POST ABG control in spring. In greenhouse experiments, the combination of mesotrione (280 g ai ha−1) and amicarbazone (75 g ai ha−1) controlled ABG 70% by 21 d after treatment, > 29% more than either herbicide applied alone; these combinations were determined to be synergistic. Amicarbazone combined with topramezone (14.5 g ai ha−1) provided < 10% ABG control and was not synergistic. When combined with mesotrione, increasing amicarbazone rate to 150 or 255 g ha−1did not increase ABG control compared to 75 g ha−1in field experiments. Combining mesotrione with amicarbazone resulted in a synergistic increase in POST ABG control at 1 and 2 wk after treatment (WAT). When applied alone or in combination with amicarbazone, increasing the mesotrione rate from 90 to 280 g ha−1increased efficacy on ABG in field experiments. The combination of mesotrione at 280 g ha−1and amicarbazone at 75 g ha−1provided > 90% ABG control in field experiments. Future research should focus on sequential applications of mesotrione–amicarbazone combinations for ABG control in locations where ABG is historically more difficult to control.


2013 ◽  
Vol 27 (3) ◽  
pp. 520-526 ◽  
Author(s):  
Matthew D. Jeffries ◽  
Fred H. Yelverton ◽  
Travis W. Gannon

Amicarbazone is a photosystem II–inhibiting herbicide recently registered for annual bluegrass control in established turf systems that include creeping bentgrass. However, research to date reveals potential issues with creeping bentgrass tolerance to amicarbazone. Currently, the plant-growth regulator paclobutrazol is widely adopted by turf managers for chemical annual bluegrass suppression in creeping bentgrass putting greens. Field experiments were conducted throughout North Carolina in the spring of 2010 and 2011 to assess treatment regimens that included amicarbazone (49, 65, or 92 g ai ha−1) and paclobutrazol (70, 140, or 280 g ai ha−1) applied alone, as tank-mixtures, or used in tandem, at varying rates and sequential timings for annual bluegrass control in creeping bentgrass putting greens. In general, regimens including both compounds provided greater annual bluegrass control and acceptable turfgrass tolerance compared with stand-alone applications of amicarbazone at 8 and 12 wk after initial treatment (WAIT). When comparing regimens that included amicarbazone at 49 or 65 g ha−1, creeping bentgrass tolerance was greater for the higher application rate applied less frequently. These results indicate amicarbazone usage on creeping bentgrass greens may be beneficially affected with the incorporation of paclobutrazol to treatment regimens because annual bluegrass control with the combination was equal to or greater than stand-alone amicarbazone applications, and creeping bentgrass tolerance was superior 8 and 12 WAIT.


Weed Science ◽  
2021 ◽  
pp. 1-34
Author(s):  
David B. Westerveld ◽  
Nader Soltani ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
Patrick J. Tranel ◽  
...  

Abstract Photosystem II (PS II)-inhibitor herbicide resistance in Ontario waterhemp [Amaranthus tuberculatus (Moq.) Sauer] population is conferred via target-site resistance (TSR) and non-target-site resistance (NTSR) mechanisms. Metribuzin-resistant (MR) A. tuberculatus is due to TSR,. Conversely, in other populations of PS II-resistant A. tuberculatus, plants are resistant to atrazine but metribuzin-sensitive (MS). The objective of this study was to determine the biologically-effective-dose of metribuzin applied PRE and POST for the control of MS and MR A. tuberculatus. Ten field experiments were conducted in 2019 and 2020 to determine the effective doses of metribuzin for 50, 80, and 95% control of MS and MR A. tuberculatus. Metribuzin applied PRE at the calculated doses of 133, 350, and 1070 g ai ha-1 controlled MS A. tuberculatus 50, 80, and 95%, respectively, whereas the calculated doses of 7868 and 17533 g ai ha-1 controlled MR A. tuberculatus 50 and 80%, respectively at 12 WAA. Metribuzin applied POST at the calculated doses of 245 and 1480 g ai ha-1 controlled MS A. tuberculatus 50 and 80%, respectively; the calculated dose for 50% MR A. tuberculatus control was greater than the highest dose (17920 g ai ha-1) included in this study. Metribuzin at 560 and 1120 g ha-1 and pyroxasulfone/flumioxazin (240 g ai ha-1) applied PRE controlled MS A. tuberculatus 88, 95, and 98%, respectively at 12 WAA. The aforementioned treatments controlled MR A. tuberculatus 0, 4, and 93%, respectively at 12 WAA. Metribuzin at 560 and 1120 g ha-1 and fomesafen (240 g ai ha-1) applied POST controlled MS A. tuberculatus 65, 70, and 78%, and MR A. tuberculatus 0, 1, and 49%, respectively at 12 WAA. Based on these results, NTSR PS II-resistant A. tuberculatus (enhanced metabolism) is controlled with metribuzin applied PRE and POST, in contrast TSR PS II-resistant A. tuberculatus (glycine264serine altered target site) is not controlled with metribuzin.


2012 ◽  
Vol 26 (2) ◽  
pp. 289-293 ◽  
Author(s):  
Patrick E. McCullough ◽  
Jialin Yu ◽  
Diego Gomez de Barreda

Annual bluegrass is a troublesome weed in turf management and there are currently limited POST herbicides labeled for use in seashore paspalum. Field and greenhouse experiments were conducted to evaluate seashore paspalum tolerance to pronamide and other herbicides for annual bluegrass control. In field experiments, turf injury never exceeded 7% from pronamide applied at dormancy, 50% green-up, or complete green-up of seashore paspalum in spring. Annual bluegrass control from pronamide was initially similar across timings and averaged 67, 90, and 98% control from 0.84, 1.68, and 3.36 kg ai ha−1, respectively, after 6 wk. In greenhouse experiments, the aforementioned pronamide rates caused less than 10% injury on seashore paspalum. Seashore paspalum injury in the greenhouse was excessive (> 20%) from atrazine, bispyribac-sodium, and trifloxysulfuron and moderate (7 to 20%) from foramsulfuron, rimsulfuron, and ethofumesate. Seashore paspalum seedhead count reductions by 4 wk after treatment (WAT) were good to excellent (87 to 98%) from atrazine, bispyribac-sodium, rimsulfuron, and trifloxysulfuron and poor (≤ 0%) from ethofumesate, foramsulfuron, and pronamide. By 4 WAT, seashore paspalum clippings were reduced 0 to 39% from pronamide, whereas atrazine, bispyribac-sodium, and trifloxysulfuron reduced clippings by 54 to 69% from the untreated and ethofumesate, foramsulfuron, and rimsulfuron reduced clippings by 27 to 39%.


2012 ◽  
Vol 26 (4) ◽  
pp. 789-792 ◽  
Author(s):  
Patrick E. McCullough ◽  
Diego Gómez De Barreda

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.


2014 ◽  
Vol 28 (2) ◽  
pp. 340-350 ◽  
Author(s):  
Thomas V. Reed ◽  
Patrick E. McCullough

Flumioxazin provides PRE and POST, annual weed control in dormant bermudagrass, but applications during active growth may be injurious. Flumioxazin could also provide an alternative chemistry for POST annual bluegrass control in other turfgrasses, but research is limited on tolerance levels. The objective of this research was to evaluate tolerance of five warm-season turfgrasses to flumioxazin applied at various rates and timings. Late-winter applications of flumioxazin at 0.21, 0.42, or 0.84 kg ai ha−1caused acceptable (< 20%) injury to bermudagrass, seashore paspalum, St. Augustinegrass, and zoysiagrass at 3, 6, and 9 wk after treatment (WAT) in both years. In 2012, late-winter applications to centipedegrass caused unacceptable injury at 6 WAT, but turf recovered to acceptable levels by 9 WAT at all rates. Applications made during active turfgrass growth caused unacceptable initial injury to all species. However, bermudagrass, seashore paspalum, St. Augustinegrass, and zoysiagrass recovered to < 20% injury by 9 WAT from all rates. In 2012, centipedegrass treated in midspring had 0, 24, and 74% injury from flumioxazin at 0.21, 0.42, and 0.84 kg ha−1, respectively, at 9 WAT. In 2013, midspring applications to centipedegrass caused 13, 48, and 71% injury from 0.21, 0.42, and 0.84 kg ha−1, respectively at 9 WAT. Overall, flumioxazin has the potential to control annual weeds in bermudagrass, seashore paspalum, St. Augustinegrass, and zoysiagrass with late-winter applications before greenup, but all turfgrasses may be excessively injured during active growth.


HortScience ◽  
2022 ◽  
Vol 57 (1) ◽  
pp. 10-16
Author(s):  
Matthew T. Elmore ◽  
Aaron J. Patton ◽  
Adam W. Thoms ◽  
Daniel P. Tuck

Annual bluegrass (Poa annua L.) control with postemergence herbicides in cool-season turfgrass is often inconsistent. Amicarbazone and mesotrione have complementary modes of action but have not been evaluated in tank-mixtures for control of mature annual bluegrass in cool-season turfgrass. Field experiments were conducted during 2018 in New Jersey, and in Indiana, Iowa, and New Jersey during 2019 to evaluate springtime applications of amicarbazone and mesotrione for POST annual bluegrass control in cool-season turfgrass. On separate tall fescue (Festuca arundinacea Schreb.) and kentucky bluegrass (Poa pratensis L.) sites in 2018, three sequential applications of amicarbazone (53 g⋅ha−1) + mesotrione at 110 to 175 g⋅ha−1 provided >70% annual bluegrass control, whereas three sequential applications of amicarbazone alone at 53 and 70 as well as two sequential applications at 110 g⋅ha−1 provided <15% control at 14 weeks after initial treatment (WAIT). In 2019, results in New Jersey were similar to 2018 where amicarbazone alone provided less control than mesotrione + amicarbazone tank-mixtures. In Indiana, where the annual bluegrass infestation was severe and most mature, tank-mixtures were more effective than amicarbazone alone at 6 WAIT, but at 12 WAIT all treatments provided poor control. In Iowa, where the annual bluegrass infestation was <1 year old, all treatments provided similar control throughout the experiment and by >80% at the conclusion of the experiment. This research demonstrates that sequential applications of mesotrione + amicarbazone can provide more annual bluegrass control than either herbicide alone, but efficacy is inconsistent across locations, possibly due to annual bluegrass maturity and infestation severity.


1993 ◽  
Vol 48 (3-4) ◽  
pp. 163-167
Author(s):  
Koichi Yoneyama ◽  
Yoshihiro Nakajima ◽  
Masaru Ogasawara ◽  
Hitoshi Kuramochi ◽  
Makoto Konnai ◽  
...  

Abstract Through the studies on structure-activity relationships of 5-acyl-3-(1-aminoalkylidene)-4-hydroxy-2 H-pyran-2,6(3 H)-dione derivatives in photosystem II (PS II) inhibition, overall lipophilicity of the molecule was found to be a major determinant for the activity. In the substituted N -benzyl derivatives, not only the lipophilicity but also the electronic and steric characters of the substituents greatly affected the activity. Their mode of PS II inhibition seemed to be similar to that of DCMU , whereas pyran-enamine derivatives needed to be highly lipophilic to block the electron transport in thylakoid membranes, which in turn diminished the permeability through biomembranes.


2020 ◽  
pp. 1-8
Author(s):  
Clebson G. Gonçalves ◽  
Austin M. Brown ◽  
Suma Basak ◽  
J. Scott McElroy

Abstract Few options are available for controlling bermudagrass invasion of seashore paspalum. Bermudagrass and seashore paspalum tolerance to topramezone, triclopyr, or the combination of these two herbicides were evaluated in both greenhouse and field conditions. Field treatments included two sequential applications of topramezone (15.6 g ai ha−1) alone and five rates of topramezone + triclopyr (15.6 + 43.2, 15.6 + 86.3, 15.6 + 172.6, 15.6 + 345.2, or 15.6 g ai ha−1 + 690.4 g ae ha−1). Secondary greenhouse treatments included a single application of topramezone (20.8 g ha−1) or triclopyr (258.9 g ha−1) alone, or in combination at 20.8 + 258.9 or 20.8 + 517.8 g ha−1, respectively. Greenhouse and field results showed that topramezone applications in combination with triclopyr present opposite responses between bermudagrass and seashore paspalum. Topramezone increased bermudagrass injury and decreased seashore paspalum bleaching injury compared to topramezone alone. In field evaluations, topramezone + triclopyr at 15.6 + 690.4 g ha−1 used in sequential applications resulted in >90% injury to bermudagrass, however, injury decreased over time. Furthermore, sequential applications of topramezone + triclopyr at 15.6 + 690.4 g ha−1 resulted in >50% injury to seashore paspalum. Application programs including topramezone plus triclopyr should increase bermudagrass suppression and reduce seashore paspalum injury compared to topramezone alone. However, additional studies are needed because such practices will likely require manipulation of topramezone rate, application timing, application interval, and number of applications in order to maximize bermudagrass control and minimize seashore paspalum injury.


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