In dense flower clusters. Its appearance is the result of a precise biological progression, dictated entirely by whether environmental factors favor or inhibit its growth. O_O
Botrytis is a necrotrophic pathogen O_o unlike powdery mildew, it kills host cells and feeds on the dead tissue rather than extracting nutrients from living cells.
Its spores are everywhere. They exist in virtually every growing environment.
Germination requires very specific conditions: relative humidity above 90% sustained for several hours, temperatures between 60–77°F (15–25°C), and wounded or senescent plant tissue as an entry point.
This is why botrytis almost always starts inside dense flower structures rather than on exposed leaf surfaces.
Inside a tight cola, the microclimate humidity can exceed ambient tent humidity by a significant margin. Dense trichome coverage restricts air exchange, moisture from transpiring tissue gets trapped, and the internal bud environment stays highly humid even when your consistent conditions look perfect on paper.
The first cells to die are usually damaged trichomes, aging calyx tissue, or small leaf fragments trapped deep in the bud. These dead cells release moisture and nutrients O_O exactly what botrytis needs to establish.
Once inside, the fungus secretes enzymes (cellulase and pectinase) that break down plant cell walls, killing healthy tissue and rapidly expanding the infection outward.
The gray fuzzy sporulation you eventually see is millions of conidia being released from already dead tissue. At that point, neighboring colas are already receiving heavy spore loads that can start new infections within hours.
So a Critical removal rule is
When you cut out infected material, do it gently. Disturbing sporulating tissue releases massive conidia clouds that can contaminate everything they touch.
This biology explains the hard harvest decision experienced growers understand O_o
When botrytis shows up in week seven, you don’t treat it and hope for week nine. Attempting treatment while aiming for a nine week finish is futile.
To me, that sounds like pure torture, so I would simply nuke the entire crop O_o even though I have personally never encountered it. O_O
The infection is already systemically established in surrounding tissue before visible symptoms appear.
The clock starts the moment you see gray… not when the infection began.
Keep on Growing O_O
