Turfgrass Epistemology

In this episode of Turfgrass Epistemology, I sit down with Dr. John Inguagiato to discuss his peer-reviewed research on phosphite use for suppressing cyanobacteria (blue-green algae) on putting greens. Together, we break down the science behind phosphite chemistry, application rates, turf safety, and what the data actually say—beyond marketing claims.

Dr. Inguagiato’s 2017 Crop Science paper, “Effect of Phosphite Rate and Source on...

In this video I take a close, critical look at "Data-Drive Lawn Care" (https://www.youtube.com/watch?v=pjRXNcIi3Hk) and share my honest thoughts on what works — and what doesn’t. I break down the arguments, highlight where I think the logic falls short, and offer my own perspective on the topic.

🔎 What I cover:

Key claims made by the original creator

Moments where I agree — and moments where I respectfully disagree Glaring omissio...

In this video, I review and break down one of the most referenced articles in cool-season turfgrass pathology: “Severity of Gray Leaf Spot in Perennial Ryegrass as Influenced by Mowing Height and Nitrogen Level” by Williams, Burrus, and Vincelli (2001).

This study investigated how two major management practices—mowing height and nitrogen rate—affect the intensity of gray leaf spot (Pyricularia grisea) epidemics in perennial ryegras...

In this video, I provide an in-depth, evidence-based critique of the nitrogen-efficiency product RDX-N and the claims made in the promotional video circulating online. If you’ve ever wondered whether biostimulants, nitrogen enhancers, or “metabolic activators” actually work in real-world turfgrass or crop management, this breakdown is for you. I review the product’s marketing claims, examine the data presented in the official RDX-N...

In this episode of Turfgrass Epistemology, I sit down with Dr. Lee Miller of Purdue University, one of the leading experts in turfgrass pathology, to break down everything you need to know about turfgrass disease resistance, fungicide rotations, and accurate turf disease identification. Whether you manage golf course greens, sports fields, or home lawns, this conversation gives you the practical, science-based guidance needed to pr...

In this video, I analyze the 2025 Zhang et al. study on how fungicide scheduling and bentgrass cultivar resistance interact to influence dollar spot control. This research provides some of the strongest evidence to date that curative, damage-threshold-based fungicide programs can dramatically reduce inputs—up to 78 percent in certain cases—when paired with disease-resistant bentgrass cultivars. I explain how the researchers designe...

In this video, I break down one of the most influential papers ever written on turfgrass pathology: Walsh, Ikeda, and Boland’s 1999 review on the biology and management of dollar spot. This paper remains a foundational resource for understanding how the pathogen operates, why the disease is so persistent on cool-season turf, and which management strategies are supported by evidence rather than tradition. I walk through the key sect...

In this episode of Turfgrass Epistemology, I review a popular lawn-care website article and an accompanying YouTube video that teach homeowners how to interpret a soil test that is, in reality, scientifically invalid for making nutrient decisions. These resources look polished and authoritative, but the advice they provide is fundamentally flawed — and following it can lead to unnecessary product applications, wasted money, and inc...

Not all scientific journals are created equal. Some exist to advance knowledge — others exist to collect publishing fees. In this episode of Turfgrass Epistemology, we explore how to tell the difference.

I’ll walk through the refereed process and explain how it differs from standard peer review, why that distinction matters, and how the structure of editorial oversight determines the credibility of the science that reaches the publ...

In this episode of Turfgrass Epistemology, we take a close look at one of the most frequently cited studies in turfgrass pathology — Golembiewski and Danneberger’s 1998 Agronomy Journal paper exploring how trinexapac-ethyl (TE) and nitrogen fertility influence the severity of dollar spot (Sclerotinia homoeocarpa) in creeping bentgrass.

The researchers found that TE, a popular plant growth regulator, didn’t increase disease as many ...

In this episode, I sit down to talk about a topic that’s been at the heart of American higher education for more than a century — university extension. We’ll explore how extension began, why it was once the lifeblood of land-grant universities, and how the system that connected science to society is now quietly disappearing.

Extension was created so universities could serve the public — not just by publishing papers, but by helping...

Can something as simple as mowing time really stop a turfgrass disease? In this episode of Turfgrass Epistemology, we look back at a landmark 1996 study by Williams, Powell, Vincelli, and Dougherty from the University of Kentucky — a paper that changed how superintendents think about dew, nitrogen, and dollar spot control.

Dollar spot (Sclerotinia homoeocarpa) thrives on leaf moisture. Williams et al. tested what happens when you s...

In this video, I explore the history and current state of university turfgrass programs—from their rise during the post-war boom in golf, parks, and sports fields to their decline in recent decades. I explain how turfgrass faculty positions are created and filled, what factors lead to the loss of those positions, and why many programs are now disappearing altogether. I connect the dots between enrollment trends, industry funding, a...

In this video, I examine the 2021 study by Beckley and Roberts published in the International Turfgrass Society Research Journal titled “Utilizing Organic Amendments for General Suppression of Dollar Spot on Creeping Bentgrass.” The discussion centers on one key question: Does biochar actually reduce dollar spot? I break down the experimental design—how researchers compared biochar, compost, vermicompost, and traditional fertilizer...

In this video, I explore the recent review article “Review of the Biology and Management of Large Patch of Warm-Season Turfgrasses” (Kreinberg et al., Crop Science, 2025). I walk you through what the authors tell us about Rhizoctonia solani AG 2-2 LP — the fungal pathogen behind large patch disease in warm-season turfgrasses — how environmental conditions favor its development, and how it can persist in thatch through seasonal dorm...

In this video, I take you through the state of the science on dollar spot disease in turfgrass, framed by the recent review “New Approaches to an Old Problem: Dollar Spot of Turfgrass.” We explore how this ubiquitous fungal disease (caused by Clarireedia spp.) continues to challenge turf managers, why traditional fungicide programs are increasingly under pressure, and what new genomic tools and breeding strategies may offer as solu...

In this video, I dive into the article “Survey of Water Use and Management Practices on US Golf Courses from 2005 to 2024” published in HortTechnology (Shaddox et al., 2025). The study tracks nearly twenty years of changes in how golf courses across the United States use and manage water. I discuss how irrigation volumes and irrigated areas have shifted over time, highlight important regional differences, and explain why some water...

In this video, I discuss the YouTube episode “Struggling Turf? Calcium Could Be the Missing …” and examine it through the lens of the strawman fallacy. We’ll look at how someone can present information that is technically true, yet still mislead by reframing the issue or knocking down an argument no one actually made.

This breakdown shows how a conman can be both truthful and deceptive at the same time—a powerful reminder of why cr...

In this video, I review the scientific article “Irrigation Frequency Affects Zoysiagrass Rooting and Plant Water Status.” We’ll look at how different irrigation schedules influenced root development and water relations in zoysiagrass, and what these findings mean for turfgrass management. If you’ve ever wondered how often you should water to encourage deeper roots and better turf performance, this study offers valuable evidence-bas...