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,