093: Vineyard Nutrition Essentials - Phosphorus Fundamentals with Dr. Terry Bates
Release Date: 03/17/2026
096: Do Plant Growth Regulators Have a Place in Winegrapes with Dr. Matthew Fidelibus
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Plant growth regulators (PGRs) are powerful tools that can dramatically influence vine performance, but they also come with complexity and risk. In this episode, Fritz welcomes back Dr. Matthew W. Fidelibus of UC Davis to explore how these compounds are used across table, raisin, and wine grape production. Dr. Fidelibus explains that PGRs include both naturally occurring plant hormones and synthetic compounds that mimic hormonal effects. While they’ve long been foundational in table grape production, their use in winegrapes is far less common and more nuanced. The conversation highlights how...
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095: Transitioning from Conventional to Organic Grape Farming with Rob Warren
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094: Vineyard Nutrition Essentials - Magnesium Fundamentals with Dr. Jaclyn Fiola
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093: Vineyard Nutrition Essentials - Phosphorus Fundamentals with Dr. Terry Bates
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Phosphorus may not grab attention like nitrogen or potassium, but it plays a foundational role in vine growth, fruit set, and overall vineyard performance. In this episode of Vineyard Underground, Fritz welcomes Dr. Terry Bates, Senior Research Associate at Cornell University and Director of the Cornell Lake Erie Research and Extension Lab for Cornell AgriTech, for a deep dive into phosphorus fundamentals. Drawing on decades of research in plant nutrition and root biology, Dr. Bates explains what phosphorus is, where it comes from, and why it is essential for grapevines at the cellular level....
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092: Vineyard Nutrition Essentials - Nitrogen Fundamentals with Dr. Markus Keller
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In this first installment of a three-part vineyard nutrition series, Dr. Markus Keller joins us to break down one of the most influential nutrients in vineyard management: nitrogen. We explore from the ground up. Dr. Keller explains what nitrogen is, where it comes from in vineyard soils, and why it plays such a critical role in vine growth, fruit set, and overall vine performance. While nitrogen makes up 78% of the atmosphere, vines rely on soil processes to convert it into plant-available forms like nitrate. Dr. Keller details how nitrogen influences vigor, canopy density, fruit set,...
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091: Rare Grape Varieties & Their Wines with Jolie-Laide Wines
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090: Old Vines and Argentina's Ungrafted Massale Selection with Dr. Laura Catena
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Some of the world’s most valuable vineyard lessons are rooted in vines that predate modern viticulture. In this conversation, we are joined by Dr. Laura Catena to explore Argentina’s remarkable legacy of old, ungrafted vines and what they reveal about vine genetics, site expression, and long-term resilience. Drawing on her experience, Dr. Catena explains why phylloxera never devastated many Argentine vineyards and how this unique history allowed ancient vine material to survive. The discussion dives into massale selection from old vines, highlighting why genetic diversity matters —...
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089: Red Flags for Planting a Vineyard with Dr. Mark Greenspan
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Planting a vineyard is a major investment, and the decisions made before the first vine goes into the ground can determine long-term success or costly failure. In this episode, Fritz sits down with renowned viticulture expert Dr. Mark Greenspan to unpack the most common red flags vineyard owners and operators should watch for when planning a new planting. Drawing on more than three decades of scientific research and hands-on field experience, Dr. Greenspan explains why many vineyard problems originate long before planting day. Fritz and Dr. Greenspan also discuss the dangers of relying on...
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088: Pruning Q&A with Fritz Westover
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Pruning is one of the most influential decisions vineyard owners and operators make each season, and in this solo Q&A episode, Fritz tackles the most common — and most misunderstood — questions he hears in the field. Drawing on hands-on experience, Fritz walks listeners through the practical realities of dormant pruning, why it matters far beyond vine appearance, and how pruning choices directly impact vine balance, yield, and long-term vineyard health. Throughout the episode, Fritz addresses real-world concerns from growers, including how aggressive pruning should be, what mistakes...
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087: Mothballing a Vineyard - What Growers Need to Know with Dr. Christopher Chen
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A topic that many growers consider but few understand is mothballing a vineyard. In this episode, Fritz covers it all with Dr. Christopher Chen, Integrated Vineyard Systems Advisor with the University of California Cooperative Extension. With economic pressures, market shifts, and operational challenges affecting vineyard owners across the industry, temporarily idling a vineyard can feel like a practical option — but it comes with important agronomic, legal, and financial considerations. Dr. Chen brings a research-based, boots-on-the-ground perspective to the conversation, helping listeners...
info_outlinePhosphorus may not grab attention like nitrogen or potassium, but it plays a foundational role in vine growth, fruit set, and overall vineyard performance. In this episode of Vineyard Underground, Fritz welcomes Dr. Terry Bates, Senior Research Associate at Cornell University and Director of the Cornell Lake Erie Research and Extension Lab for Cornell AgriTech, for a deep dive into phosphorus fundamentals.
Drawing on decades of research in plant nutrition and root biology, Dr. Bates explains what phosphorus is, where it comes from, and why it is essential for grapevines at the cellular level. From its role in energy transfer and DNA structure to its influence on root growth and fruit development, phosphorus is woven into nearly every aspect of vine physiology.
Vineyard owners and operators will walk away with useful guidance on managing phosphorus efficiently while protecting both yield and long-term soil health.
In this episode, you will hear:
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Phosphorus drives energy transfer, root development, and fruit set
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Soil pH directly impacts phosphorus availability and uptake
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Mycorrhizal fungi are essential partners in grapevine phosphorus nutrition
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Excess phosphorus application wastes money and reduces efficiency
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Tissue sampling helps balance nutrient supply, uptake, and vine demand
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Resources:
Visit www.virtualviticultureacademy.com/sampling to access Fritz’s how-to guides and videos for proper sampling and target nutrient values.
Learn more about Mycorrhizal Fungi in Episode 75 - The Importance of Mycorrhizal Fungi for Vineyard Health with Dr. R. Paul Schreiner.
Come grow with Fritz through https://www.virtualviticultureacademy.com! Save $75 off your first year of membership with the code Underground at checkout.
Have a vineyard question? Go to VineyardUndergroundPodcast.com and click the Ask Fritz button.
Today’s Guest:
Dr. Terry Bates is the Senior Research Associate at Cornell University and the Director of the Cornell Lake Erie Research and Extension Lab for Cornell AgriTech.
Connect with Terry
· Cornell Research & Publications - https://cals.cornell.edu/people/terry-bates
· The Efficient Vineyard Project - https://www.efficientvineyard.com/
Episode Sponsor:
Today’s episode was brought to you by Shellt Grow Tubes and Bahco Tools.
Thank you to Shellt Grow Tubes for sponsoring today’s episode. Shellt makes the ultimate grow tubes for grape vines and orchard trees. Their grow tubes are reusable, recyclable, and designed to grow with your vineyard by clicking together for taller or wider coverage. I exclusively recommend Shellt Grow Tubes to the growers I work with. Visit https://www.shellt.us/ and order with the code UNDERGROUND to save 15% off all online orders, plus free shipping within the continental United States.
Thank you to Bahco Tools for sponsoring today’s episode. As innovators for more than 165 years, Bahco has introduced the most advanced tools in the world, and Bahco products are manufactured in factories across Europe. I exclusively prune with the Bahco ERGO™ Bypass Secateurs with Elastomer Coated Fixed Handle (size medium). Visit www.bahco.com/int_en to find a dealer near you to get the best pruning tools on the market, along with loppers, hedging tools, cutting blades, files, and more.
Episode Credits
If you like this podcast and are thinking of creating your own, consider talking to my producer, Emerald City Productions. They helped me grow and produce the podcast you are listening to right now. Find out more at https://emeraldcitypro.com. Let them know we sent you.