S4 E1 Does Potassium Influence Dollar Spot?

In this episode of Turfgrass Epistemology, I walk through a recent peer-reviewed study that examines how potassium fertilization influences dollar spot severity on annual bluegrass (Poa annua) and creeping bentgrass (Agrostis stolonifera) putting greens. The article, Potassium fertilization effects on dollar spot of annual bluegrass and creeping bentgrass, presents multi-year field data showing that increasing potassium rates consistently increased dollar spot severity under the conditions tested. This directly challenges the common assumption that potassium fertilization automatically improves stress tolerance or reduces disease pressure in turfgrass systems. In the video, I explain the experimental design, including potassium and nitrogen rate treatments, mat layer and leaf tissue measurements, and how disease severity was quantified over time. I also discuss why potassium behaved differently than many turf managers expect, and how disease response depended on antecedent potassium levels in both the mat layer and plant tissue. This discussion emphasizes the importance of context in fertility management. Potassium is an essential nutrient, but its relationship with turfgrass disease is not linear or universally beneficial. The results highlight why relying on generalized nutrient “rules” without soil and tissue data can lead to unintended consequences in disease management programs. If you manage golf course putting greens, work in turfgrass research, or make fertility decisions based on soil tests and tissue analysis, this episode provides critical insight into how potassium, nitrogen, and dollar spot interact in real turf systems. The goal is not to discourage potassium use, but to encourage evidence-based decision-making grounded in measured nutrient status rather than assumptions. Subscribe for more long-form turfgrass science discussions, peer-reviewed paper breakdowns, and practical explanations focused on how we know what we know in turfgrass management. 🔔 Subscribe for more evidence-based turfgrass content, scientific paper discussions, and long-form explanations that go beyond social media soundbites. #Turfgrass #SoilScience #LawnCare #GolfCourseManagement #TurfgrassScience #SoilFertility #CriticalThinking #TurfTok #TurfgrassEpistemology #EvidenceBased #LawnCareTips 📌 https://www.gofundme.com/f/TurfgrassEpistemology Thank you for being part of this community and for supporting evidence-based turfgrass science. Join Turfgrass Epistemology to get access to perks: https://www.youtube.com/channel/UC-UZnHkJhAmARDZ4YoHnc_A/join Voicemail: 859-444-4234 Apple Podcast https://podcasts.apple.com/us/podcast/turfgrass-epistemology/id1717271379 Spotify Podcast https://open.spotify.com/show/1cTpdrChToeEFAOX9wkXFI iHeart Radio Podcast https://www.iheart.com/podcast/1323-turfgrass-epistemology-129043524/ Podbean https://turfgrassepistemology.podbean.com/ Online consulting Calendly.com/TravisShaddox Twitter Twitter.com/TravisShaddox Email [email protected] Turfgrass Programs and Extension Service Information: https://www.usna.usda.gov/assets/images/as_pdf_image/LandGrantColleges.pdf Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view