The Turf Zone Podcast

ATA Turf Times – Dave Han, Ph.D., Associate Professor & Extension Specialist & Adam Boyd, Graduate Research Assistant, Department of Crop, Soil, & Environmental Sciences Auburn University

Bahiagrass (Paspalum notatum) is a commonly-used grass for utility turf (roadsides, airports, etc.) and lawns in the southeastern United States. In Alabama, it is planted extensively by the Alabama Department of Transportation (ALDOT) as a permanent ground cover along roadsides (ALDOT, 2018). It is also used at many airfields, construction sites, utility rights of way, and some lawns. Bahiagrass has many advantages: it can be easily established by seed, is inexpensive, has an extensive root and rhizome system, has excellent drought tolerance, and does not require heavy fertilization. The major disadvantage of bahiagrass is that it produces many tall, unsightly seedheads. These grow quickly and can be two or three feet high only a few days after mowing. Mostly because of its seedheads, bahiagrass is not a popular choice for home and commercial lawns in areas where appearance is a high priority. Seedheads can also be a hazard on roadsides if they grow tall enough to block drivers’ views.

Although mowing twice per week can control bahiagrass seedheads, this is often not practical. There are chemical methods to suppress seedhead formation and growth in bahiagrass. Low rates of herbicides such as imazapic (e.g. Plateau), metsulfuron (e.g. Escort, Manor, MSM Turf), sulfometuron-methyl (e.g. Oust) and glyphosate (e.g. Roundup) can be used to suppress seedhead formation (Murphy et al., 2005). These so-called “sub-lethal” rates still can produce unacceptable injury in bahiagrass (Yelverton et al. 2011). Some research (Sellers et al., 2011) has indicated that adding 2,4-D, an auxin mimic broadleaf herbicide, can safen metsulfuron application somewhat in bahiagrass pastures. Aminocyclopyrachlor is an auxin-mimic herbicide that is labeled for use on turf under the trade name ‘Method.’ Aminocyclopyrachlor has been shown to both suppress seedheads in bahiagrass for at least 60 days after treatment and also to stunt and discolor bahiagrass at high rates (Durham et al., 2011).

In this project, we looked at a combination of aminocyclopyrachlor (as Method) and a product containing the herbicides foramsulfuron, iodosulfuron and thiencarbizone (Derigo) for seedhead control and damage to an established stand of bahiagrass on the roadside along US Highway 231 north of Wetumpka, Alabama. We also tested metsulfuron (MSM Turf) at very low rates. Derigo is labeled for seedhead suppression in bahiagrass, but it recommends that sprays begin after the bahiagrass is fully green. ALDOT often wishes to make herbicide applications in the spring before bahiagrass is fully greened up (H. Peavey, personal communication), to control late winter broadleaf weeds. We made single applications of various herbicides commonly used on roadsides by ALDOT beginning on April 1, 2019 to determine how early application, before bahiagrass greenup was complete, affected both phytotoxicity and seedhead suppression. The latest application was made on May 27.

The herbicide treatments in this study were:

* Derigo (2 oz/acre) + Method (4 oz/acre)

* Derigo (3 oz/acre) + Method (4 oz/acre)

* MSM Turf (0.125 oz/acre)

* MSM Turf (0.25 oz/acre)

Since metsulfuron will kill bahiagrass at regular label rates, we used very low rates in an attempt to achieve seedhead suppression with minimal phytotoxicity.

Each treatment was applied as a single application on either April 1, April 14, April 29, May 13 or May 27, then followed through August and rated for bahiagrass coverage and seedhead suppression.

 

Results

Bahiagrass damage was much less severe when herbicides were applied early in the season and was progressively worse as the season wore on. As expected,

Tennessee Turfgrass – D.E. Carroll & J.T. Brosnan

In certain regions of the United States and Canada, legislation has severely restricted traditional synthetic herbicide use in residential and commercial landscapes. Specifically, residential use of synthetic pesticides deemed “cosmetic use” in the Ontario Province, Canada, has been banned. Other aspects of the turfgrass industry such as sports and golf are able to receive exemptions through government approval, stated reduction goals, integrated pest management certification, and increased transparency requiring reporting and in-person meetings to discuss pesticide application. (Ontario Regulation, 2018). Similarly, in Montgomery County, Maryland, the use of synthetic pesticides perceived for use cosmetically is banned. Only natural, non-synthetic herbicides listed by the Organic Materials Review Institute (OMRI) may be used for this purpose (County Council for Montgomery County, Maryland, 2019). Many local governments, such as the city of New York, banned glyphosate use on public land such as school districts, parks and in municipalities, except for maintenance of invasive plants in native area. (The New York City Council, 2019).

In the United States, many active ingredients in organic pesticides are considered minimum risk, categorized as section 25b products, and are exempt from the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) registration process. Products must meet six criteria for inclusion in this category. Because labeling in this category is typically not federally regulated, labeling of non-synthetic herbicides is not consistent and may include wording such as “organic” or “natural”, despite these products not undergoing typical organic product registration.  Although not required by federal law, independent agencies perform organic standard research to determine which products receive organic seals on labeling (Figure 1). Additionally, individual states may still require a registration process for minimum risk products and may limit herbicide use in some areas to only products listed by independent testing agencies. An example of a natural product research agency that maintains a list of products compliant with internal organic standards is OMRI. OMRI is a non-profit organization, and thus not considered a regulatory agency. Conversely, the Environmental Protection Agency is considered a regulatory agency and although not federally required, also tests natural products and lists those meeting organic criteria.

Active ingredients on these lists include chelated iron, acetic acid, corn gluten meal, and a variety of soaps and oils. Chelated iron, also referred to as Iron HEDTA, is concentrated iron formulated for increased uptake in broadleaved weeds versus grasses. Once inside the plant, the iron is oxidized and causes necrosis (Charbonneau, 2010). Acetic acid, which is concentrated in household vinegar used for cooking at 5%, is generally concentrated in horticultural vinegar at 20 to 40%. Horticultural vinegar applications can kill weeds by removing the waxy cuticle found on leaves, thus drying out the plant. Citrus oil and soaps such as pelargonic acid or ammoniated fatty acid work in similar fashion by stripping the leaf cuticle to facilitate water loss. Unlike many synthetic herbicides, products with these active ingredients are generally fast acting and results may be observed within a few hours of application (Figure 2).

Products containing these active ingredients are widely available to the public and can be purchased at most big box retail stores and online (Figure 3). Due to the lack of regulation in labeling, many manufacturers produce products of differing trade names that have similar active ingredients included at variable concentrations. For example, horticultural vinegar is available as Green Gobbler concentrated at 20, 30, or 40% acetic acid; Eco Garden Pro (8% acetic acid + 5% sodium chloride); or ...

Mississippi Turfgrass – J. Bryan Unruh, Professor and Associate Director

Introduction

The use of ride-on applicators in the landscape is common in the northern and transition zones of the United States. However, it has only been in recent years that these machines have made their way south. Ride-on applicator use on warm-season landscapes has been steadily rising over the past few years.

In visiting with lawn care operators, the consensus is that the increasing difficulty in finding labor is prompting the shift towards the ride-on applicators. In a leading industry survey, 56% of survey respondents listed labor as a major concern.[i] The challenge is due to the aging workforce and the difficulty in attracting younger workers. A cursory review of Lawn & Landscape Magazine reveals several articles aimed at attracting and retaining young employees. The use of ride-on applicators is seen as a key move to keep younger workers satisfied.[ii] Ride-on applicators also allow for increased productivity since one can spray and spread at the same time. Additionally, ride-on applicators require less manual labor, putting an end to dragging hoses or pushing spreaders. The advantages and disadvantages of the ride-on applicators are listed in Table 1.

Types of Ride-on Applicators

There are basically two types of ride-on applicators: Spreader only and Spreader/Sprayer. The spreader only applicators are useful for applying granular products such as fertilizer or fertilizer sparged with a pesticide. Examples include the Ferris Rover™ Ride-On Spreader, the Spyker Ride-On Spreader, and the LESCO HPS Chariot Ride-On Spreader. Retail pricing for spreader only models range from $4,600 – $6,775.

The Spreader/Sprayer applicators allow for singular or simultaneous application of both dry and liquid products. There are two types of sprayer designs: Boomless and boom-type. The boomless sprayers employ a cluster of FloodJet® type nozzles that distribute the spray solution through a single nozzle operating at a given time. The boom sprayer, as the name implies, has three or four nozzles uniformly spaced along a rigid boom. Examples include the PermaGreen, Ferris Venture™, Z-Spray, and the Turfco T3100 Spreader & Sprayer. Retail pricing for the Spreader/Sprayer systems range from $10,000 – $13,000.

Calibrating Ride-on Pesticide Sprayers and Fertilizer Spreaders

As with any fertilizer or pesticide application equipment, calibration is critical for achieving effective pest control and providing uniform greening without yellow streaking from fertilizer misapplications. When combining two distribution methods (granular and liquid), the calibration can be quite challenging. Fortunately, Purdue University Extension has a fantastic publication on Calibrating Ride-on Pesticide Sprayers and Fertilizer Spreaders available as a free download (https://ppp.purdue.edu/wp-content/uploads/2016/08/PPP-104.pdf).

Do Ride-on Applicators Work as Well as Conventional Equipment?

As noted, proper calibration is the first step in achieving success with any application equipment. The application of fertilizer using a ride-on applicator does not differ too much from a standard push spreader. Assuming the machine is operated in the intended manner, one can achieve uniform results. Conversely, the spray delivery systems on ride-on applicators can offer some unique challenges that differ from conventional landscape sprayers – namely the low volume applications and operating the equipment in small, tight areas.

Historically, most lawncare spray volumes ranged from 1.0 – 3.0 gallons per 1,000 ft2 [43 – 130 gallons per acre (gpa)] delivered through industry standard spray guns such as the Lesco ChemLawn Spray Gun or the JD9® High Pressure Spray Gun.

Mississippi Turfgrass – Michael Goatley, Jr., Ph.D., Professor and Extension Turfgrass Specialist, School of Plant and Environmental Sciences, Virginia Tech

Nothing reminds us of how fragile our lives, jobs, and relationships are until they are seriously disrupted by an unforeseen event. If you’re anywhere near my age (58) then 9/11 and 4/16 have particular significance in our lives, and Covid-19 will be another event that will be remembered for how it changed the way we do things, even in managing turfgrasses. The 2020 Pandemic has certainly impacted the turfgrass industry and its effects will continue even as/after social distancing restrictions are relaxed and public activities on our sports fields and golf courses expand and/or return. For situations where budgets and labor forces were not severely impacted by the pandemic, turfgrass managers have taken advantage of the downtime in what are typical high turfgrass use periods to complete a variety of activities/projects that otherwise would not have been possible. I have noted irrigation and drainage installations, bunker renovations, a wide variety of tree management activities, earlier than ever spring transition of ryegrass overseeding back to bermudagrass, rebuilding/renovating infield skins, pitching mounds, and batter’s boxes, etc. The only ‘slaps on the hand’ for the turfgrass managers that I have heard in these situations has been admonishments in some cases for not paying enough attention to ‘social distancing.’ However, the real world scenario for many turfgrass managers has been that they have had to be ultra-creative in managing their labor forces, not just to address social distancing guidelines, but to handle a budget that has been cut and might continue to shrink. Predicting what is going to happen for the rest of 2020 in our industry will likely be as accurate as most of our pandemic models have been to this point in time because this is such a fluid situation; it’s unchartered territory from a variety of perspectives and perceptions. However, necessity brings out the best (and sometimes worst) of human ingenuity, and quite often our management and business models will never be the same again. In listening to and observing industry peers from around the mid-Atlantic, here’s some forecasting that even if it doesn’t pan out as I think it will, should still be applicable strategies to fit most turfgrass management situations:

Site-specific management continues. This is one of the oldest and best budget saving strategies in all phases of turfgrass management. Focus management on the areas that warrant the attention because of their specialized purpose or their intensity of use. Logically it’s greens, tees, and fairways in that order on golf courses and it’s been interesting watching how superintendents are adjusting pest, fertility, and mowing strategies to deal with current and anticipated challenges in budgets and labor. Similar concepts are being applied in sports fields with an emphasis on repairing and restoring the heaviest trafficked areas, and only providing minimal maintenance on most other areas. The classic example long preached in sports field management is to emphasize turf recovery between the hashes and the 30s in the spring on football fields, even when they are being used for spring soccer. Focus on infields and hips on grassed baseball and softball facilities and minimize efforts in the outfield (except for perhaps three general locations in left, center, and right?).

Many turfgrass managers have told me that budgets simply aren’t going to allow for broad-scale scheduled aeration events, even if performed ‘in house’, and a primary reason is the cost of the tines themselves. The same limitations might apply to scheduled pesticide or fertilizer applications. Adjust the areas that you are managing to those that absolutely need the attention, and return to the other areas as budgets allow.

Tennessee Turfgrass – Julie Holt, Content Director, TheTurfZone.com

The Turf Zone: Welcome to The Turf Zone. This episode continues our series on the USDA-funded ResistPoa Project. In this episode we’re talking to Jim Brosnan, Professor at the University of Tennessee and Director of the UT Weed Diagnostic Center. Jim, thanks for joining us.

JB: Thanks for having me on.

 

TTZ: Let’s dive into this project that you are a participant with many other researchers. Most turfgrass scientists have had, for lack of better words, a professional relationship with annual bluegrass for their entire career. What’s your poa story?

JB: My poa story… Wow, I’ve never been asked that before. You know, it’s funny, I’ll contend it’s the most amazing plant out there, at least that affects the turf world. It’s a weed in certain situations and it’s a desirable in other situations, and the adaptability piece of it is off the charts high. I mean, we have poa documented on every continent, including Antarctica. Which when you wrap your mind around that, it’s kinda nuts. For me as a weed scientist, as resistance issues have worsened, I think my first resistance interaction with poa came in the late 2000s, early 2010-ish. I was on an extension visit in West Tennessee about a drainage issue and putting greens and we were looking at putting greens and taking root zone profiles and talking about layering within the root zone and surface drainage versus internal drainage and building a plan for how to combat that at this golf course. And as we were going back to my truck in the parking lot, the superintendent told me, “Have you ever seen Roundup not kill annual bluegrass?” I said, “Well, I’ve never seen it, I’ve heard about it in row crop situations, but I’ve never seen it in turf.” He said, “Well, I’ve got fairways of it. Why don’t you hop in the cart and we’ll go have a look?” And that’s kind of where it all started for me, and then it became one of those scenarios where the more that I would give presentations and talk about this, the more individuals in the audience would come up to me afterwards and say, “Hey, I think I’ve got an issue, can you come visit me and have a look?” And it kind of grew from there to be the number one weed that my program here at the University of Tennessee works on. The students and staff that work for me joke that it’s poa 365 around here. 365 days a year it’s part of the conversation.

 

TTZ: Sounds like a pretty serious origin story of your relationship. So how does annual bluegrass rank in the list of weeds in Tennessee?

JB: That’s a hard question to answer because it all depends on what those rankings are based on. Are the rankings based on what’s the hardest to control, are the rankings based on what’s the most prevalent? Is the ranking based on what’s most widespread? I think regardless of how you define the parameters, poa would be on the list. We’re in a climate in Tennessee where it’s almost kind of a perfect storm in the transition zone, where warm season grasses are going to go dormant for extended periods and really offer no competition against poa invasion. We also have climatic conditions that can favor poa growth for extended periods. Not only in the winter, but sometimes even into the late spring. As we’re recording this now, in June, there are areas on golf courses where you can find healthy, mature poa plants. That’s one of the things I think we need to do more research on is to understand the environments that maybe facilitate that survival because that complicated management. The paradigm is that this is a true annual, and in most cases that paradigm is correct. There certainly could be environments out there where maybe we can get persistence that looks more like a perennial than an annual.

 

TTZ: Coming back to the scope of the ResistPoa Project, what objectives are you pursuing as part of that project, and as a side note,

North Carolina Turfgrass – Julie Holt, Content Director, TheTurfZone.com

The Turf Zone: Welcome to The Turf Zone. This episode continues our series on the USDA-funded ResistPoa Project. In this episode we’re talking to Jim Brosnan, Professor at the University of Tennessee and Director of the UT Weed Diagnostic Center. Jim, thanks for joining us.

JB: Thanks for having me on.

 

TTZ: Let’s dive into this project that you are a participant with many other researchers. Most turfgrass scientists have had, for lack of better words, a professional relationship with annual bluegrass for their entire career. What’s your poa story?

JB: My poa story… Wow, I’ve never been asked that before. You know, it’s funny, I’ll contend it’s the most amazing plant out there, at least that affects the turf world. It’s a weed in certain situations and it’s a desirable in other situations, and the adaptability piece of it is off the charts high. I mean, we have poa documented on every continent, including Antarctica. Which when you wrap your mind around that, it’s kinda nuts. For me as a weed scientist, as resistance issues have worsened, I think my first resistance interaction with poa came in the late 2000s, early 2010-ish. I was on an extension visit in West Tennessee about a drainage issue and putting greens and we were looking at putting greens and taking root zone profiles and talking about layering within the root zone and surface drainage versus internal drainage and building a plan for how to combat that at this golf course. And as we were going back to my truck in the parking lot, the superintendent told me, “Have you ever seen Roundup not kill annual bluegrass?” I said, “Well, I’ve never seen it, I’ve heard about it in row crop situations, but I’ve never seen it in turf.” He said, “Well, I’ve got fairways of it. Why don’t you hop in the cart and we’ll go have a look?” And that’s kind of where it all started for me, and then it became one of those scenarios where the more that I would give presentations and talk about this, the more individuals in the audience would come up to me afterwards and say, “Hey, I think I’ve got an issue, can you come visit me and have a look?” And it kind of grew from there to be the number one weed that my program here at the University of Tennessee works on. The students and staff that work for me joke that it’s poa 365 around here. 365 days a year it’s part of the conversation.

 

TTZ: Sounds like a pretty serious origin story of your relationship. So how does annual bluegrass rank in the list of weeds in Tennessee?

JB: That’s a hard question to answer because it all depends on what those rankings are based on. Are the rankings based on what’s the hardest to control, are the rankings based on what’s the most prevalent? Is the ranking based on what’s most widespread? I think regardless of how you define the parameters, poa would be on the list. We’re in a climate in Tennessee where it’s almost kind of a perfect storm in the transition zone, where warm season grasses are going to go dormant for extended periods and really offer no competition against poa invasion. We also have climatic conditions that can favor poa growth for extended periods. Not only in the winter, but sometimes even into the late spring. As we’re recording this now, in June, there are areas on golf courses where you can find healthy, mature poa plants. That’s one of the things I think we need to do more research on is to understand the environments that maybe facilitate that survival because that complicated management. The paradigm is that this is a true annual, and in most cases that paradigm is correct. There certainly could be environments out there where maybe we can get persistence that looks more like a perennial than an annual.

 

TTZ: Coming back to the scope of the ResistPoa Project, what objectives are you pursuing as part of that project, and as a side note,

MTC Turf News – Julie Holt, Content Director, TheTurfZone.com

The Turf Zone: Welcome to The Turf Zone. This episode continues our series on the USDA-funded ResistPoa Project. In this episode we’re talking to Jim Brosnan, Professor at the University of Tennessee and Director of the UT Weed Diagnostic Center. Jim, thanks for joining us.

JB: Thanks for having me on.

 

TTZ: Let’s dive into this project that you are a participant with many other researchers. Most turfgrass scientists have had, for lack of better words, a professional relationship with annual bluegrass for their entire career. What’s your poa story?

JB: My poa story… Wow, I’ve never been asked that before. You know, it’s funny, I’ll contend it’s the most amazing plant out there, at least that affects the turf world. It’s a weed in certain situations and it’s a desirable in other situations, and the adaptability piece of it is off the charts high. I mean, we have poa documented on every continent, including Antarctica. Which when you wrap your mind around that, it’s kinda nuts. For me as a weed scientist, as resistance issues have worsened, I think my first resistance interaction with poa came in the late 2000s, early 2010-ish. I was on an extension visit in West Tennessee about a drainage issue and putting greens and we were looking at putting greens and taking root zone profiles and talking about layering within the root zone and surface drainage versus internal drainage and building a plan for how to combat that at this golf course. And as we were going back to my truck in the parking lot, the superintendent told me, “Have you ever seen Roundup not kill annual bluegrass?” I said, “Well, I’ve never seen it, I’ve heard about it in row crop situations, but I’ve never seen it in turf.” He said, “Well, I’ve got fairways of it. Why don’t you hop in the cart and we’ll go have a look?” And that’s kind of where it all started for me, and then it became one of those scenarios where the more that I would give presentations and talk about this, the more individuals in the audience would come up to me afterwards and say, “Hey, I think I’ve got an issue, can you come visit me and have a look?” And it kind of grew from there to be the number one weed that my program here at the University of Tennessee works on. The students and staff that work for me joke that it’s poa 365 around here. 365 days a year it’s part of the conversation.

 

TTZ: Sounds like a pretty serious origin story of your relationship. So how does annual bluegrass rank in the list of weeds in Tennessee?

JB: That’s a hard question to answer because it all depends on what those rankings are based on. Are the rankings based on what’s the hardest to control, are the rankings based on what’s the most prevalent? Is the ranking based on what’s most widespread? I think regardless of how you define the parameters, poa would be on the list. We’re in a climate in Tennessee where it’s almost kind of a perfect storm in the transition zone, where warm season grasses are going to go dormant for extended periods and really offer no competition against poa invasion. We also have climatic conditions that can favor poa growth for extended periods. Not only in the winter, but sometimes even into the late spring. As we’re recording this now, in June, there are areas on golf courses where you can find healthy, mature poa plants. That’s one of the things I think we need to do more research on is to understand the environments that maybe facilitate that survival because that complicated management. The paradigm is that this is a true annual, and in most cases that paradigm is correct. There certainly could be environments out there where maybe we can get persistence that looks more like a perennial than an annual.

 

TTZ: Coming back to the scope of the ResistPoa Project, what objectives are you pursuing as part of that project, and as a side note,

Virginia Turfgrass Journal – Julie Holt, Content Director, TheTurfZone.com

The Turf Zone: Welcome to The Turf Zone. This episode continues our series on the USDA-funded ResistPoa Project. In this episode we’re talking to Jim Brosnan, Professor at the University of Tennessee and Director of the UT Weed Diagnostic Center. Jim, thanks for joining us.

JB: Thanks for having me on.

 

TTZ: Let’s dive into this project that you are a participant with many other researchers. Most turfgrass scientists have had, for lack of better words, a professional relationship with annual bluegrass for their entire career. What’s your poa story?

JB: My poa story… Wow, I’ve never been asked that before. You know, it’s funny, I’ll contend it’s the most amazing plant out there, at least that affects the turf world. It’s a weed in certain situations and it’s a desirable in other situations, and the adaptability piece of it is off the charts high. I mean, we have poa documented on every continent, including Antarctica. Which when you wrap your mind around that, it’s kinda nuts. For me as a weed scientist, as resistance issues have worsened, I think my first resistance interaction with poa came in the late 2000s, early 2010-ish. I was on an extension visit in West Tennessee about a drainage issue and putting greens and we were looking at putting greens and taking root zone profiles and talking about layering within the root zone and surface drainage versus internal drainage and building a plan for how to combat that at this golf course. And as we were going back to my truck in the parking lot, the superintendent told me, “Have you ever seen Roundup not kill annual bluegrass?” I said, “Well, I’ve never seen it, I’ve heard about it in row crop situations, but I’ve never seen it in turf.” He said, “Well, I’ve got fairways of it. Why don’t you hop in the cart and we’ll go have a look?” And that’s kind of where it all started for me, and then it became one of those scenarios where the more that I would give presentations and talk about this, the more individuals in the audience would come up to me afterwards and say, “Hey, I think I’ve got an issue, can you come visit me and have a look?” And it kind of grew from there to be the number one weed that my program here at the University of Tennessee works on. The students and staff that work for me joke that it’s poa 365 around here. 365 days a year it’s part of the conversation.

 

TTZ: Sounds like a pretty serious origin story of your relationship. So how does annual bluegrass rank in the list of weeds in Tennessee?

JB: That’s a hard question to answer because it all depends on what those rankings are based on. Are the rankings based on what’s the hardest to control, are the rankings based on what’s the most prevalent? Is the ranking based on what’s most widespread? I think regardless of how you define the parameters, poa would be on the list. We’re in a climate in Tennessee where it’s almost kind of a perfect storm in the transition zone, where warm season grasses are going to go dormant for extended periods and really offer no competition against poa invasion. We also have climatic conditions that can favor poa growth for extended periods. Not only in the winter, but sometimes even into the late spring. As we’re recording this now, in June, there are areas on golf courses where you can find healthy, mature poa plants. That’s one of the things I think we need to do more research on is to understand the environments that maybe facilitate that survival because that complicated management. The paradigm is that this is a true annual, and in most cases that paradigm is correct. There certainly could be environments out there where maybe we can get persistence that looks more like a perennial than an annual.

 

TTZ: Coming back to the scope of the ResistPoa Project, what objectives are you pursuing as part of that project, and as a side note,

Mississippi Turfgrass – Julie Holt, Content Director, TheTurfZone.com

The Turf Zone: Welcome to The Turf Zone. This episode continues our series on the USDA-funded ResistPoa Project. In this episode we’re talking to Jim Brosnan, Professor at the University of Tennessee and Director of the UT Weed Diagnostic Center. Jim, thanks for joining us.

JB: Thanks for having me on.

 

TTZ: Let’s dive into this project that you are a participant with many other researchers. Most turfgrass scientists have had, for lack of better words, a professional relationship with annual bluegrass for their entire career. What’s your poa story?

JB: My poa story… Wow, I’ve never been asked that before. You know, it’s funny, I’ll contend it’s the most amazing plant out there, at least that affects the turf world. It’s a weed in certain situations and it’s a desirable in other situations, and the adaptability piece of it is off the charts high. I mean, we have poa documented on every continent, including Antarctica. Which when you wrap your mind around that, it’s kinda nuts. For me as a weed scientist, as resistance issues have worsened, I think my first resistance interaction with poa came in the late 2000s, early 2010-ish. I was on an extension visit in West Tennessee about a drainage issue and putting greens and we were looking at putting greens and taking root zone profiles and talking about layering within the root zone and surface drainage versus internal drainage and building a plan for how to combat that at this golf course. And as we were going back to my truck in the parking lot, the superintendent told me, “Have you ever seen Roundup not kill annual bluegrass?” I said, “Well, I’ve never seen it, I’ve heard about it in row crop situations, but I’ve never seen it in turf.” He said, “Well, I’ve got fairways of it. Why don’t you hop in the cart and we’ll go have a look?” And that’s kind of where it all started for me, and then it became one of those scenarios where the more that I would give presentations and talk about this, the more individuals in the audience would come up to me afterwards and say, “Hey, I think I’ve got an issue, can you come visit me and have a look?” And it kind of grew from there to be the number one weed that my program here at the University of Tennessee works on. The students and staff that work for me joke that it’s poa 365 around here. 365 days a year it’s part of the conversation.

 

TTZ: Sounds like a pretty serious origin story of your relationship. So how does annual bluegrass rank in the list of weeds in Tennessee?

JB: That’s a hard question to answer because it all depends on what those rankings are based on. Are the rankings based on what’s the hardest to control, are the rankings based on what’s the most prevalent? Is the ranking based on what’s most widespread? I think regardless of how you define the parameters, poa would be on the list. We’re in a climate in Tennessee where it’s almost kind of a perfect storm in the transition zone, where warm season grasses are going to go dormant for extended periods and really offer no competition against poa invasion. We also have climatic conditions that can favor poa growth for extended periods. Not only in the winter, but sometimes even into the late spring. As we’re recording this now, in June, there are areas on golf courses where you can find healthy, mature poa plants. That’s one of the things I think we need to do more research on is to understand the environments that maybe facilitate that survival because that complicated management. The paradigm is that this is a true annual, and in most cases that paradigm is correct. There certainly could be environments out there where maybe we can get persistence that looks more like a perennial than an annual.

 

TTZ: Coming back to the scope of the ResistPoa Project, what objectives are you pursuing as part of that project, and as a side note,

Arkansas Turfgrass – Julie Holt, Content Director, TheTurfZone.com

The Turf Zone: Welcome to The Turf Zone. This episode continues our series on the USDA-funded ResistPoa Project. In this episode we’re talking to Jim Brosnan, Professor at the University of Tennessee and Director of the UT Weed Diagnostic Center. Jim, thanks for joining us.

JB: Thanks for having me on.

 

TTZ: Let’s dive into this project that you are a participant with many other researchers. Most turfgrass scientists have had, for lack of better words, a professional relationship with annual bluegrass for their entire career. What’s your poa story?

JB: My poa story… Wow, I’ve never been asked that before. You know, it’s funny, I’ll contend it’s the most amazing plant out there, at least that affects the turf world. It’s a weed in certain situations and it’s a desirable in other situations, and the adaptability piece of it is off the charts high. I mean, we have poa documented on every continent, including Antarctica. Which when you wrap your mind around that, it’s kinda nuts. For me as a weed scientist, as resistance issues have worsened, I think my first resistance interaction with poa came in the late 2000s, early 2010-ish. I was on an extension visit in West Tennessee about a drainage issue and putting greens and we were looking at putting greens and taking root zone profiles and talking about layering within the root zone and surface drainage versus internal drainage and building a plan for how to combat that at this golf course. And as we were going back to my truck in the parking lot, the superintendent told me, “Have you ever seen Roundup not kill annual bluegrass?” I said, “Well, I’ve never seen it, I’ve heard about it in row crop situations, but I’ve never seen it in turf.” He said, “Well, I’ve got fairways of it. Why don’t you hop in the cart and we’ll go have a look?” And that’s kind of where it all started for me, and then it became one of those scenarios where the more that I would give presentations and talk about this, the more individuals in the audience would come up to me afterwards and say, “Hey, I think I’ve got an issue, can you come visit me and have a look?” And it kind of grew from there to be the number one weed that my program here at the University of Tennessee works on. The students and staff that work for me joke that it’s poa 365 around here. 365 days a year it’s part of the conversation.

 

TTZ: Sounds like a pretty serious origin story of your relationship. So how does annual bluegrass rank in the list of weeds in Tennessee?

JB: That’s a hard question to answer because it all depends on what those rankings are based on. Are the rankings based on what’s the hardest to control, are the rankings based on what’s the most prevalent? Is the ranking based on what’s most widespread? I think regardless of how you define the parameters, poa would be on the list. We’re in a climate in Tennessee where it’s almost kind of a perfect storm in the transition zone, where warm season grasses are going to go dormant for extended periods and really offer no competition against poa invasion. We also have climatic conditions that can favor poa growth for extended periods. Not only in the winter, but sometimes even into the late spring. As we’re recording this now, in June, there are areas on golf courses where you can find healthy, mature poa plants. That’s one of the things I think we need to do more research on is to understand the environments that maybe facilitate that survival because that complicated management. The paradigm is that this is a true annual, and in most cases that paradigm is correct. There certainly could be environments out there where maybe we can get persistence that looks more like a perennial than an annual.

 

TTZ: Coming back to the scope of the ResistPoa Project, what objectives are you pursuing as part of that project, and as a side note,