{"podcast":{"title":"Vineyard Underground","slug":"vineyard-underground-6280933","podcast_index_feed_id":6280933,"rss_url":"https://f364ccd0-b8ab-4504-aea4-3e21b899bc22.libsyn.com/rss","website_url":"https://www.vineyardundergroundpodcast.com/","image_url":"https://static.libsyn.com/p/assets/a/b/3/9/ab390a1f09536c4d27a2322813b393ee/Final_Vineyard_underground_1.jpg","author":"Fritz Westover","episode_count":100,"summary":"What if you could hang out with experienced grape growers, ask them about the science of grape growing, vineyard operations, and more; then take an insight or two to improve your vineyard and ultimately the quality of the wines you produce? That's what we do each week on the Vineyard Underground. Hosted by Fritz Westover –– viticulture expert more than 20 years of experience in the vineyard industry –– every episode is an in-depth look at grape growing methods, care, and even complicated matters of fertilization and pest and disease management? The goal is to provide you with an understanding of the complicated aspects of viticulture science so that experienced and even first-time grape growers will be able to understand and implement new practices in their vineyard.","last_synced_at":"2026-06-09T18:17:07.711312+00:00","page_url":"https://stenobird.com/podcast/vineyard-underground-6280933"},"episode":{"title":"096: Do Plant Growth Regulators Have a Place in Winegrapes with Dr. Matthew Fidelibus","slug":"096-do-plant-growth-regulators-have-a-place-in-winegrapes-with-dr-matthew-fidelibus","published_at":"2026-04-28T08:00:00+00:00","page_url":"https://stenobird.com/podcast/vineyard-underground-6280933/096-do-plant-growth-regulators-have-a-place-in-winegrapes-with-dr-matthew-fidelibus","show_page_url":"https://stenobird.com/podcast/vineyard-underground-6280933","url":"https://f364ccd0-b8ab-4504-aea4-3e21b899bc22.libsyn.com/096-do-plant-growth-regulators-have-a-place-in-winegrapes-with-dr-matthew-fidelibus","audio_url":"https://traffic.libsyn.com/secure/f364ccd0-b8ab-4504-aea4-3e21b899bc22/VU_Ep096_Master.mp3?dest-id=3650511","summary":"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 sensitivity to timing, rate, and variety is critical, with even small misapplications potentially affecting fruit set, bud development, or yields across multiple seasons. Fritz and Dr. Fidelibus dig into specific compounds like gibberellic acid, abscisic acid, and ethephon, discussing how they can influence berry size, cluster architecture, color development, and ripening. They also explore emerging research on improving color in virus-affected vineyards, delaying ripening in warm climates, and even modifying aroma profiles. A key takeaway is that PGRs are not a one-size-fits-all solution. They require careful evaluation, regulatory compliance, and, ideally, small-scale trials before broader use. For growers facing challenges like poor fruit set, uneven ripening, or compact clusters, these tools may offer targeted solutions — but only when used with precision and a strong understanding of vine physiology. Listeners will walk away with a clearer understanding of both the potential and the pitfalls of incorporating PGRs into vineyard management. In this episode, you will hear: Overview of plant growth regulators and how they influence vine physiology Historical use of PGRs in table a…","meta_description":"Plant growth regulators (PGRs) are powerful tools that can dramatically influence vine performance, but they also come with complexity and risk. In this e…","key_points":[],"chapters":[],"topics":[],"duration_seconds":3060,"processing_state":"not_requested","actions":[{"name":"request_transcript","method":"POST","url":"https://stenobird.com/v1/public/podcasts/vineyard-underground-6280933/episodes/096-do-plant-growth-regulators-have-a-place-in-winegrapes-with-dr-matthew-fidelibus/transcription-requests","description":"Idempotently request low-priority transcript generation for this episode."},{"name":"read_markdown","method":"GET","url":"https://stenobird.com/podcast/vineyard-underground-6280933/096-do-plant-growth-regulators-have-a-place-in-winegrapes-with-dr-matthew-fidelibus.md","description":"Read the agent-friendly Markdown representation of this episode resource."}]}}