Cannabis Cultivation and Science Podcast · Tad Hussey

Episode 161: The Secret Lives of Pathogens with Dr. Zamir Punja

·1 hr 11 min·4 clips

Larger cannabis buds trap more heat and humidity, and the flower center can run 2–3°C warmer.

Tad Hussey introduces Dr. Zamir Poonja as a professor of plant pathology and biotechnology at Simon Fraser University and as a leading authority on cannabis diseases. That background matters. Poonja brings more than three decades of plant-disease research in high-value horticultural crops into a conversation about cannabis pathogens, and that gives the episode its weight. The focus stays practical. Hussey asks how Fusarium, which many growers think of as a root disease, can show up on flowers and move through a facility. Poonja says it can. He describes two routes: airborne spread from nearby sources, and movement through the plant's internal vascular system, especially the xylem. He also points out that Fusarium is seed borne, which makes internal movement hard to ignore because the pathogen can end up in seed after traveling through the plant. The conversation then turns to what growers can do with that information. Poonja says the broad cultural responses used for Botrytis apply here as well, especially when the problem is framed as Fusarium bud rot. The work is familiar: remove infected material, reduce relative humidity, and remove leaves off your plants. He also notes that trichoderma remains an open question for Fusarium rather than a settled answer. Early sprays come up in that context, but he does not claim more certainty than the data allow. The episode keeps coming back to timing. Poonja warns that the most dangerous bud-rot window may begin earlier than growers assume, which changes how you think about scouting and intervention. By the end, the lesson is less about a single fix than about spotting disease pressure sooner and acting with discipline in the room or greenhouse.

As heard by us

A grounded look at how Fusarium moves, spreads, and starts the damage.

Fusarium bud rot gets a clear, practical treatment here: it is shown as a problem that can show up on flowers as well as roots, which changes how a room gets managed.

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Why you'd press play

You want the mechanics behind Fusarium and bud rot, not just the warning label.

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