Golf course superintendents may use bensulide to control annual grassy weeds and carfentrazone‐ethyl (CE) to control silvery‐thread moss (Bryum argenteum Hedw.) in creeping bentgrass putting greens. Creeping bentgrass injury has been reported if CE is applied soon after treatment with bensulide and the safe application interval varies as much as 68 days. Our goal was to improve the precision of recommendations for safe application of CE following bensulide, considering both CE rate and timing. We used a factorial treatment structure that included (1) bensulide or no bensulide, (2) three rates of CE, and (3) nine CE application timings in 2018 and 2019 at locations in Nebraska and Ohio. Because of limited effects in 2018, different CE rates and application timings were used in 2019. Significant creeping bentgrass injury was only observed at 6.7 or 13.4 fl oz acre−1 rates of CE that were applied within 3 days of applying bensulide. Even the 13.4 fl oz acre−1 rate (a 2× rate) of CE did not injure creeping bentgrass when applied at least 7 days after applying bensulide. The 2.0 fl oz acre−1 rate of CE never injured creeping bentgrass, even when applied the same day as bensulide. Cultivar, management, and environmental differences may influence whether subsequent application of bensulide and CE injures creeping bentgrass. Based on the environmental/cultural conditions and cultivars used in this research, golf course superintendents should expect little to no injury when CE is applied at least 1 week after applying bensulide.

Microtubule-associated protein 65-1 (MAP65-1) protein plays an essential role in plant cellular dynamics through impacting stabilization of the cytoskeleton by serving as a crosslinker of microtubules. The role of MAP65-1 in plants has been associated with phenotypic outcomes in response to various environmental stresses. The Arabidopsis MAP65-1 (AtMAP65-1) is a known virulence target of plant bacterial pathogens and is thus a component of plant immunity. Soybean events were generated that carry transgenic alleles for both AtMAP65-1 and GmMAP65-1, the soybean AtMAP65-1 homolog, under control of cauliflower mosaic virus 35S promoter. Both AtMAP65-1 and GmMAP65-1 transgenic soybeans are more resistant to challenges by the soybean bacterial pathogen Pseudomonas syringae pv. glycinea and the oomycete pathogen Phytophthora sojae, but not the soybean cyst nematode, Heterodera glycines. Soybean plants expressing AtMAP65-1 and GmMAP65-1 also display a tolerance to the herbicide oryzalin, which has a mode of action to destabilize microtubules. In addition, GmMAP65-1-expressing soybean plants show reduced cytosol ion leakage under freezing conditions, hinting that ectopic expression of GmMAP65-1 may enhance cold tolerance in soybean. Taken together, overexpression of AtMAP65-1 and GmMAP65-1 confers tolerance of soybean plants to various biotic and abiotic stresses. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Abstract Yellow nutsedge is one of the most widely distributed and troublesome weeds in the world. Field and greenhouse studies were conducted to optimize strategies for increased yellow nutsedge control in turfgrass with halosulfuron and sulfentrazone. In the field study in yellow nutsedge and perennial ryegrass mixture, single or sequential applications (3 wk after initial) of halosulfuron or sulfentrazone were made on June 3, June 23, July 15, or August 5 in 2013, 2014, 2015, and 2016. Percent yellow nutsedge control was rated within the same growing season on September 17 and the following year on June 3 for carryover control. Field and greenhouse studies confirm that sequential applications of halosulfuron with a 3-wk interval resulted in >95% control in a yellow nutsedge–turfgrass mixture. In a greenhouse study, both herbicides reduced yellow nutsedge root and rhizome dry mass from 39% to 98%, reduced number of new tubers and tuber fresh weight from 38% to 100%, and prevented re-emergence. Sequential applications of either herbicide within a 3-wk interval early postemergence is recommended for optimal control. Herbicide application to yellow nutsedge using halosulfuron and sulfentrazone should be made as early as possible postemergence, preferably at the three- to five-leaf stage or 200 to 250 growing degree days (GDD, 10 C base). Mowing can be an effective method to reduce yellow nutsedge growth. Mowing at 7.6 cm weekly reduced yellow nutsedge rhizome dry mass by 55% and number of new tubers formed by 63% in the greenhouse study. Physical removal of yellow nutsedge plants such as hand-pulling can be an effective method to manage yellow nutsedge and is most effective at the three- to five-leaf stage (200 to 250 GDD). End-users can maximize yellow nutsedge control by integrating early herbicide treatments and cultural practices such as mowing and hand-pulling. Nomenclature: Halosulfuron; sulfentrazone; yellow nutsedge, Cyperus esculentus L.; perennial ryegrass, Lolium perenne L.

Annual bluegrass (ABG) (Poa annua L.) is a prolific seed producer in the spring on golf courses that in turn decreases aesthetic quality and trueness of ball roll on cool-season putting greens. Proxy (ethephon) applied twice in the spring after green-up is the current industry standard after the loss of Embark (mefluidide) from the turf and ornamental market. However, plant growth regulators including Proxy have been used for years to help suppress ABG seedheads with inconsistent success. The primary objective of this study was to determine if ABG seedhead suppression is improved by adding a late fall application of Proxy to the two traditional spring applications of plant growth regulators at nine locations with diverse environments. A second objective was to determine the importance of including Primo Maxx (trinexapac-ethyl) in fall and spring applications. Adding a late fall application of Proxy prior to the two spring applications (F+S+S) improved control of ABG seedheads over the traditional two spring applications (S+S), but the magnitude of improvement varied among locations.

Annual bluegrass (Poe annua L.; ABG) is among the most common weeds of highly maintained turf in the United States. Though many labeled active ingredients exist for control in golf course fairways, few labeled options exist for putting greens. Further, ABG has demonstrated resistance to several herbicide modes of action commonly used on fairway turf. The use of a systems approach coupling cultural and chemical controls with diverse modes of action could limit the potential for further ABG resistance development. Our objective was to evaluate a systems approach to ABG control on putting greens by examining seven season-long programs of plant growth regulators, herbicides, and/or iron sulfate fertilizer with July or September hollow tine aerification over 2 or 4 years in three Midwestern US states. Aerification timing did not influence annual bluegrass cover at any of the three locations. The effectiveness of season-long treatments varied by location, but methiozolin, paclobutrazol, or bispyribac-sodium consistently reduced ABG. Monthly applications of iron sulfate alone did not effectively control ABG. Several treatments reduced ABG, but none completely removed annual bluegrass. Currently, methiozolin and bispyribac-sodium are not registered for use on putting greens in the US but show potential to control ABG. As such, paclobutrazol was the most effective product of those tested that is currently available for use on US putting greens. Future availability of herbicides such as methiozolin and bispyribac-sodium would provide needed options to allow for the rotation or addition of multiple-control strategies in an ABG control system to limit resistance development.

Core Ideas Sequential applications of either halosulfuron or sulfentrazone improve control better than single applications. Rotating the herbicide mode of action is recommended to help minimize the development of herbicide resistance. Halosulfuron should be applied first in rotation with sulfentrazone within a year.

In the Great Plains of the United States, mixtures of Kentucky bluegrass (KBG) and perennial ryegrass (PRG) are used to establish or renovate golf course fairways or interseed existing fairways after summer damage. Kentucky bluegrass is the preferable permanent species in the Great Plains, whereas PRG is used primarily for quick germination and establishment. Stand composition is affected by weather, management factors, and weed competition such as from annual bluegrass (ABG) and thus is difficult to predict from any given seed mixture of KBG and PRG. Our objective was to follow species composition for 3 years in fairway-height stands seeded in mid-August with different ratios of KBG and PRG and treated immediately after seeding and yearly thereafter with annual bluegrass herbicides. On the research site with almost no ABG competition, all seeding mixtures (50-100% KBG: 50-0% PRG wt:wt) except 100% PRG produced turf stands with > 94% KBG cover 3 years after seeding. There were no adverse effects of multiple applications of ethofumesate or mesotrione starting 4 weeks after seeding (WAS) in spite of these applications being earlier than label recommendations. On the site with substantial ABG pressure, increasing PRG in the seed mixture hastened turf coverage, and seed ratios of 80% or more KBG resulted in >= 80% KBG coverage after 3 years. Moreover, initiating ABG herbicides applications shortly after emergence and again each fall maximized short-term turf establishment and KBG coverage after 3 years, as well as minimized ABG coverage after 3 year.

Core Ideas The fall is the optimum time to control winter annual and perennial broadleaf weeds. More information is needed on postemergence herbicide safety in the fall as buffalograss enters winter dormancy. Many postemergence herbicides can be safely applied to buffalograss entering winter dormancy with no effect on spring greenup. Turf managers have many herbicide and application timing options for weed control in buffalograss.

Environmental factors like drought impact the quality of biomass entering a bioconversion process. Drought often reduces the sugar content in lignocellulosic biomass, which could have economic impacts, particularly when compounded with losses in dry biomass yield; however, the effects on conversion efficiency are not completely understood. This study investigated how drought may impact biomass composition and sugar yields from dilute-acid pretreatment and enzymatic hydrolysis of Miscanthus, a tall fescue mixture, and switchgrass from Nebraska, Missouri, and Oklahoma, respectively, grown as part of Regional Feedstock Partnership field trials. Samples were grown and harvested in 2010 during non-drought conditions and in 2012 during extreme drought conditions. Non-structural glucose and proline were significantly greater in 2012 compared with 2010 for Miscanthus, which suggests drought stress occurred. Structural glucan and xylan were significantly decreased in 2012 for Miscanthus; however, reactivity and sugar yields from dilute-acid pretreatment and enzymatic hydrolysis were significantly greater in 2012 compared with 2010, suggesting that although structural sugars may decrease during drought conditions, sugar yields and reactivity may increase. For the tall fescue mixture, proline was greater, and structural sugars were lower in 2012, indicating drought stress, but minimal differences were observed in the conversion experiments. Few differences were observed for switchgrass composition and reactivity between years. The observed patterns are likely because of site-specific climatic conditions combined with the tolerance each species may have to drought. As drought occurrence and severity have increased, it is necessary to understand drought impacts to mitigate risks to future bioenergy industry growth.

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small‐scale and short‐term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy ( US DOE )/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long‐term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field‐scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm‐scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM ‐ ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country.

Core Ideas Many postemergence herbicides can be safely applied during buffalograss greenup in early to mid‐April (0% greenup) with little chance of turf damage. Herbicide that does not contain 2,4‐D can be safely applied during buffalograss greenup until 1 June (70‐85% greenup). Herbicide containing 2,4‐D should be applied before the first week of May (10‐15% greenup) for turf safety concerns, or apply no later than third week of May (50‐60% greenup) for acceptable stand during the summer months.

Core Ideas Research done on annual bluegrass (ABG) control in other areas of the US are likely applicable to Nebraska. However, extreme weather can dramatically affect short‐term annual bluegrass cover and emphasize the need for long‐term control studies. Three fall POST applications of mesotrione plus prodiamine applied preemergence in August and/or November were effective for ABG control in Kentucky bluegrass fairways. Replacing mesotrione with ethofumesate was also effective when combined with prodiamine in August and November. June applications of bispyribac‐sodium at 4 oz/ac was highly effective for controlling ABG in creeping bentgrass fairways, and adding two more fall applications at the same rate improved control slightly, but there was no benefit to raising the rate to 6 oz/ac. Annual bluegrass (Poa annua L.) (ABG) is common in golf courses, and its control has been thoroughly researched in cool‐season turf east of the Mississippi River in the United States. However, ABG response to herbicides varies widely among environments and/or biotypes, and little ABG control research has been done in the northern Great Plains. Therefore, our objective was to validate ABG herbicide control systems in golf course fairways of Kentucky bluegrass (Poa pratensis L.) (KBG) or creeping bentgrass (Agrostis stolonifera L.) (CBG) in Nebraska. Preemergence (PRE) treatments of prodiamine or mesotrione were applied in late summer over 3 yr with or without fall postemergence (POST) treatments of mesotrione or ethofumesate for ABG control in a low‐mow KBG fairway. We also evaluated rate and frequency of bispyribac‐sodium applications with or without a late summer–applied PRE (dithiopyr) in early September for ABG control over 3 yr in a CBG fairway. Our research indicates that ABG control work done in other areas are likely applicable to Nebraska. Three fall POST applications of mesotrione plus prodiamine applied as a PRE in August and/or November was effective for ABG control in KBG fairways. Replacing mesotrione with ethofumesate was also effective when combined with prodiamine in August and November. June applications of bispyribac‐sodium at 4 oz/ac were highly effective for controlling ABG in CBG fairways, and adding two more fall applications at the same rate improved control slightly, but there was no benefit to raising the rate to 6 oz/ac. Lastly, extreme weather in one summer and one winter dramatically affected short‐term ABG cover and emphasized the need for long‐term control studies in areas with dramatic weather cycles.

Core Ideas Proper calibration and application is important when using herbicides on buffalograss. Established ‘Bowie’ buffalograss was most tolerant to carfentrazone + quinclorac, halosulfuron, indaziflam, quinclorac, quinclorac + MCCP + dicamba, simazine, sulfosulfuron, or thiencarbazone + iodosulfuron + dicamba. Herbicide injury on established buffalograss is relatively short‐lived with the exception of imazapic at the 2× rate.

Roughstalk bluegrass (Poa trivialis L.) is a cool‐season perennial turfgrass species that is more sensitive to heat stress than other cool‐season grasses. This sensitivity has been associated with increased rates of respiration compared with photosynthesis, or an inability to hydrolyze carbohydrates to simple sugars for metabolism during heat stress, but may also involve common turfgrass diseases, since roughstalk bluegrass has been shown to maintain quality from repeated applications of strobilurin fungicides in summer. Our objective was to differentiate between physiological and pathogenic contributors to roughstalk bluegrass decline and determine the effects of strobilurin fungicides on its growth and physiology. Roughstalk bluegrass was treated with azoxystrobin (Heritage 50 WDG or Heritage TL) at 610 g a.i. ha−1 or pyraclostrobin (Insignia 20 WG or Insignia SC) at 556 g a.i. ha−1 prior to summer heat stress in field plots in Manhattan, KS, (2011 and 2012) and Mead, NE (2012). Fungicides improved quality and percentage green cover over untreated roughstalk bluegrass in all studies, but fungicides rarely affected rooting or rates of gross photosynthesis. Disease sampling did not reveal any fungal pathogen consistently associated with summer turf decline. Our data suggest that nontarget physiological effects of strobilurin fungicides likely increased quality and cover over untreated roughstalk bluegrass during summer.

Core Ideas Dormant seeding of buffalograss in November can be as effective as traditional May seeding. Commercially potassium nitrate treated burs resulted in consistently higher cumulative germination regardless of seeding date. Commercial treatment of burs may not be necessary when dormant seeding in November, but maximized buffalograss germination following an exceptionally dry winter. Dormant seeding is common for establishing cool‐season turfgrasses, but minimal information exists on dormant seeding of the native warm‐season buffalograss [Buchloë dactyloides (Nutt.) Engelm.] in the Midwest and northern Great Plains of the United States. The objective of these studies was to determine the effect of commercial KNO3 seed treatment on cultivar Cody buffalograss germination when seeded at various dates in winter and spring. Cody buffalograss burs were either commercially treated or untreated and both were seeded in the field the third week of November, January, March, or May. Buffalograss cover was rated monthly until the following August. Dormant seeding in November, January, or March was as effective as seeding at the traditional May timing. Commercial treatment of burs may not be necessary when dormant seeding in November, but treated bur maximized buffalograss germination following an exceptionally dry winter. In a second study, buffalograss burs from the same source as the initial study were buried in mesh packets in the field in the third week of each month from November through April. All packets were transferred to a greenhouse in May to test germination. Commercially treated burs resulted in consistently higher cumulative germination regardless of seeding date. Cumulative germination data agreed with initial field study in that dormant seeding of buffalograss in November can be as effective as traditional May seeding.

Little information exists on dormant seeding of buffalograss [ Buchloe dactyloides (Nutt.) Engelm.]. The objectives of these two studies were to determine how seeding rate affects establishment of ‘Sundancer’ buffalograss when dormant and spring-seeded, and to evaluate if cultivar or seeding date affects establishment of ‘Cody’, ‘Bowie’, or ‘Sundancer’ buffalograss when seeded at various dates during the winter and spring. In the first study, ‘Sundancer’ buffalograss was dormant seeded at 146, 244, or 293 kg·ha −1 in late November in 2012 and 2013 or spring-seeded in early May in 2013 and 2014. In the second study, ‘Sundancer’, ‘Bowie’, or ‘Cody’ was seeded at 146 kg·ha −1 in late November in 2013 and 2014, late January, March, and May in 2014 and 2015. Dormant seeding of buffalograss resulted in >80% cover by the following August in all studies. Increasing seeding rate had no effect on establishment of ‘Sundancer’, regardless of seeding date. Furthermore, there was no difference in turf cover by August following seeding of ‘Sundancer’, ‘Bowie’, or ‘Cody’ at 146 kg·ha −1 in late November, January, March, or May. Our results suggest that ‘Sundancer’, ‘Bowie’, or ‘Cody’ can be successfully dormant seeded at 146 kg·ha −1 from late November through late March, which allows establishment before the following winter.

Two field studies (I and II) at the University of Nebraska-Lincoln: John Seaton Anderson Turfgrass Research Facility near Mead, NE, USA, were conducted to determine if a new ultra-low volume (ULV) sprayer can apply foliar nutrient, growth regulator, and fungicide treatments, in a manner similar to that of a conventional sprayer. Treatments were applied over creeping bentgrass 'L-93' (Agrostis stolonifera L.) managed as a fairway at 561 l · ha−1 and 47 l · ha−1 with the conventional and ULV sprayer, respectfully. Data were collected for chlorophyll content with a chlorophyll meter, and for the normalised difference vegetation index (NDVI) with a turf colour meter. Each plot was harvested for biomass at 21 days after treatment. Study II compared the ULV sprayer and a con- ventional sprayer, for the control of brown patch (Rhizoctonia solani Kuhn) in creeping bentgrass. The treatments were propiconazole and azoxystrobin. Spray volume was 561 l · ha−1 for the conventional sprayer, and 19 l · ha−1 for the ULV sprayer. Statistical differences in turf quality or dry weight reductions between the conventional and ULV sprayer were not detected. Brown patch control was also similar between the two sprayers, but azoxystrobin provided better control than propiconazole. Even with a 30-fold decrease in ap- plication volume, the results indicated that the Kamterter ULV sprayer may be a useful and effective management option for foliar fertiliser and fungicide applications in turfgrass.

Crop, Forage & Turfgrass ManagementVolume 2, Issue 1 cftm2015.0213 p. 1-3 Applied Turfgrass Science—Brief Evaluation of Selective Herbicide Combinations and Paclobutrazol for Rough Bluegrass Control Cole Thompson, Corresponding Author Cole Thompson Assistant Professor cthomp35@calpoly.edu Horticulture and Crop Science Dep., Cal Poly State Univ., San Luis Obispo, CA, 93407Corresponding author (cthomp35@calpoly.edu).Search for more papers by this authorMatt Sousek, Matt Sousek John Seaton Anderson Turf Research Center Manager Dep. of Agronomy & Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583Search for more papers by this authorZac Reicher, Zac Reicher Technical Specialist Bayer Environmental Science, Denton, NE, 68339Search for more papers by this authorJack Fry, Jack Fry Professor Dep. of Horticulture, Forestry, and Recreation Resources, Kansas State Univ., Manhattan, KS, 66506Search for more papers by this authorMegan Kennelly, Megan Kennelly Associate Professor Dep. of Plant Pathology, Kansas State Univ., Manhattan, KS, 66506Search for more papers by this author Cole Thompson, Corresponding Author Cole Thompson Assistant Professor cthomp35@calpoly.edu Horticulture and Crop Science Dep., Cal Poly State Univ., San Luis Obispo, CA, 93407Corresponding author (cthomp35@calpoly.edu).Search for more papers by this authorMatt Sousek, Matt Sousek John Seaton Anderson Turf Research Center Manager Dep. of Agronomy & Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583Search for more papers by this authorZac Reicher, Zac Reicher Technical Specialist Bayer Environmental Science, Denton, NE, 68339Search for more papers by this authorJack Fry, Jack Fry Professor Dep. of Horticulture, Forestry, and Recreation Resources, Kansas State Univ., Manhattan, KS, 66506Search for more papers by this authorMegan Kennelly, Megan Kennelly Associate Professor Dep. of Plant Pathology, Kansas State Univ., Manhattan, KS, 66506Search for more papers by this author First published: 14 July 2016 https://doi.org/10.2134/cftm2015.0213Citations: 1 Conversions: For unit conversions relevant to this article, see Table A. All rights reserved. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume2, Issue1December 2016Pages 1-3 RelatedInformation

Previous research has shown the effectiveness of an ULV (Ultra-Low Volume) sprayer compared to a conventional sprayer for weed control in row crop applications. This sprayer produced comparable disease control and foliar nutrient applications to a conventional sprayer in turfgrass, but has not previously been evaluated for weed control in established turf. Four weed control field studies were conducted in the spring and summer of 2012 and 2013 at the University of Nebraska-Lincoln: John Seaton Anderson Turfgrass Research Facility near Mead, NE, USA to compare the weed control efficacy between a novel ULV sprayer and a conventional sprayer. The studies compared the two sprayers for the control of: ground ivy and dandelion in established turf in a summer application; preemergence control of large crabgrass in established turf in a late spring application and ground ivy control in established turf in a late spring application. No differences were observed in weed control between sprayer types in the four studies over both years of the study despite a thirty fold decrease in application volume rate across different herbicide modes-of-action in all of the studies. The Kamterter ULV sprayer system may be a useful and effective management option for control of the weeds in turfgrass. (C) 2016 Elsevier Ltd. All rights reserved.