If you’ve stepped into your greenhouse early in the morning lately, you already know what this is about. The mist hangs low, the flowers are damp, and that’s exactly the kind of setup Botrytis loves. Every cold season, it shows up like an uninvited guest and if you’re not ready, it’ll ruin your crop before you can say “market rejection.”
This fungus isn’t new. It’s been around. But what makes the period from June to August in Kenya such a problem is the weather. Cold nights, high humidity, and limited air movement turn farms into a hub for gray mold.
Why This Season is Tough
When temps drop to 6°C at night and daytime humidity won’t budge, even farms with good airflow struggle. Condensation settles on flower petals overnight, and when the sun shows up, it’s too weak to dry it off fast enough. If you’re still irrigating late in the day, you’re making it worse.
Add slow-growing plants, tight greenhouse spacing, and workers moving through wet rows, and you’ve just built the perfect delivery service for Botrytis spores.
What Growers Are Doing
Forget chasing symptoms. The farms staying ahead this season are doing the basics.
1. Air movement matters
Even if it’s cold, open those vents when it’s dry. Use side vents and fans. A stuffy greenhouse is a sick greenhouse.
2. No water on petals. Ever
If your irrigation leaves flowers wet, adjust it. Water early, never after 10 a.m.
3. Sanitation, like your money depends on it.
Because it does. Dead leaves, old petals, moldy buds, pick them up every day. Don’t let debris pile up between plants.
4. Pre-cool like a pro.
Don’t skip pre-cooling because the weather’s cold. Flowers need to hit 2°C fast. Mold loves lukewarm boxes.
5. Stick to a Tough Fungicide Rotation
The farms ahead of this outbreak are running tight, disciplined spray programs. These are some of the products working on Kenyan farms right now:
- Fludioxonil + Cyprodinil (Switch 62.5 WG by Syngenta Kenya)
- Fenhexamid (Teldor 500 SC by Bayer CropScience)
- Boscalid + Pyraclostrobin (Bellis 33 WG by BASF Kenya)
- Pyrimethanil (Scala 400 SC by Bayer CropScience)
Ask any seasoned grower and they’ll tell you, Botrytis hits hardest when you get too comfortable. It’s a disease that waits for you to relax your guard. This cold season is already throwing challenges, but staying sharp on hygiene, airflow, and spray timing will keep your exports clean and your customers happy.
They won’t replace your main fungicides but will help reduce disease pressure and slow down resistance buildup.