Protect your crops before disease takes hold. BotryStop WP is the biological fungicide that works with nature — not against it — to outcompete gray mold, brown rot, and Sclerotinia at the source, giving your plants a clean, healthy environment to thrive from blossom to harvest.
Why BotryStop WP
BotryStop WP is powered by Ulocladium oudemansii (U3 strain), a naturally occurring saprophytic fungus that colonizes dead and senescent plant tissue — the exact ecological niche where Botrytis cinerea, Sclerotinia sclerotiorum, and Monilinia spp. thrive. Rather than relying on chemical inhibition, BotryStop WP aggressively occupies that space first, starving pathogens of the nutrients and room they need to establish.
Unlike synthetic fungicides that can trigger resistance over time, BotryStop WP's competitive exclusion mode of action makes it an ideal rotation partner and a cornerstone of any Integrated Pest Management (IPM) program. It's OMRI-listed for organic use, leaves zero residue, and carries a 0-day Pre-Harvest Interval — making it one of the most grower-friendly biocontrols on the market.
Key Benefits
- Biological Mode of Action – Uses competitive exclusion to outcompete fungal pathogens for nutrients and ecological space, reducing disease pressure without chemical inputs.
- Organic & Conventional Compatible – Approved for use in both certified organic and conventional growing programs.
- Zero Residue – Leaves no chemical residue on crops, making it ideal for fresh market and premium produce operations.
- 0-Day PHI – Can be applied right up to harvest with no waiting period required.
- 4-Hour REI – Short restricted entry interval keeps your operation moving efficiently.
- No Refrigeration Needed – Stable at room temperature for up to 12 months, simplifying storage and logistics.
- Resistance Management Tool – Exempt from residue tolerances and ideal for rotating with conventional fungicides to prevent resistance buildup.
- IPM Ready – Integrates seamlessly into existing pest and disease management programs.
Use Cases
- Greenhouse & High Tunnel Crops – Apply preventatively to tomatoes, cucumbers, peppers, and leafy greens where humidity drives Botrytis pressure.
- Cannabis & Hemp – Protect dense canopies and late-stage flowers from bud rot (Botrytis cinerea) without residue concerns at harvest.
- Vineyards & Orchards – Use during bloom and fruit set on grapes, apples, pears, cherries, peaches, and plums to prevent gray mold and brown rot.
- Berry Production – Apply to strawberries, blueberries, and caneberries throughout the season to suppress Botrytis and Monilinia.
- Ornamentals & Nurseries – Protect high-value ornamental crops from Botrytis blight and Sclerotinia without phytotoxicity risk.
- IPM Rotation Programs – Rotate with conventional fungicides to break resistance cycles and maintain long-term efficacy across seasons.
Directions for Use
- Mix BotryStop WP with water according to label rate; use of a non-ionic surfactant or spreader-sticker is recommended to improve coverage.
- Apply as a foliar spray, targeting dead and senescent plant tissue where pathogens establish.
- Begin applications preventatively — before disease pressure is observed — for best results.
- Reapply on a regular schedule as directed on the label, especially during high-humidity periods or after rain events.
- DO NOT apply through any type of irrigation or drip system.
- Observe the 4-hour Restricted Entry Interval (REI) after application.
- Refer to the manufacturer's label (DOCS tab) for full crop-specific rates and timing.
Ingredients / Guaranteed Analysis
- Active Ingredient: Ulocladium oudemansii (U3 strain) — 5 × 10⁸ CFU/g (minimum)
- Inert Ingredients: Carrier and dispersant agents
- Derived From: Naturally occurring, non-pathogenic saprophytic fungus isolated from plant material
What Growers Are Saying
"BotryStop WP has become a staple in our IPM rotation. We've seen a dramatic reduction in gray mold pressure in our greenhouse tomatoes since we started using it preventatively."
— Marcus T., Commercial Greenhouse Grower
"Easy to mix, easy to apply, and it actually works. We use it on our cannabis canopy during late flower and haven't had a bud rot issue since."
— Sarah P., Licensed Cannabis Cultivator
"The 0-day PHI is a game changer for our berry operation. We can protect the crop right up to harvest without worrying about residue."
— Daniel R., Berry Farm Manager
Frequently Asked Questions
What diseases does BotryStop WP control?
BotryStop WP is effective against Gray Mold (Botrytis cinerea), Botrytis Leaf Blight (Botrytis squamosa), Botrytis Neck Rot (Botrytis allii), Brown Rot and Blossom Blight (Monilinia spp.), Jacket Rot and Green Fruit Rot, Sclerotinia Head and Leaf Drop, Sclerotinia Stem Rot, and Erwinia amylovora. Refer to the label for crop-specific disease listings.
Is BotryStop WP safe for organic production?
Yes. BotryStop WP is approved for use in certified organic growing programs and is exempt from residue tolerances, making it compliant with organic certification requirements.
How should BotryStop WP be applied?
Apply as a foliar spray using standard spray equipment. Do not apply through irrigation systems. A non-ionic surfactant or spreader-sticker is recommended to improve coverage and adhesion.
When should I start applying BotryStop WP?
Begin applications preventatively, before disease symptoms appear. Early-season and pre-bloom applications are most effective. Continue on a regular schedule throughout the growing season, especially during high-humidity conditions.
How should BotryStop WP be stored?
Store at room temperature (no refrigeration required). Product is stable for up to 12 months when stored properly. Keep away from direct sunlight and extreme heat.
Can BotryStop WP be tank-mixed with other products?
BotryStop WP is compatible with many conventional fungicides and is designed for use in IPM rotation programs. Always conduct a jar test before tank-mixing and consult the label for compatibility guidance. Avoid mixing with strong fungicides that may harm the live spores.
More about BotryStop WP - 12 lb bag - 2U98A61:
BotryStop WP is an organic wettable powder biological fungicide based on a naturally occurring, non-pathogenic saphrophytic fungus known as Ulocladium oudemansii (U3 strain). This live spore preparation has been developed as a preventative specifically to control common plant pathogens such as Botrytis cinerea, Sclerotinia sclerotiorumand Monilinia spp.
BotryStop WP has a unique mode of action in that it aggressively occupies the same ecological space as plant pathogens and will out-compete them for nutrients. This process begins when you apply BotryStop WP spores to dead and senescent plant debris. Once applied, they will germinate and then colonize the plant debris until further sporulation occurs. Once that happens, the new spores will spread to available space on remaining dead and senescing tissue, depriving the pathogens of their room and board. This thriving colony of Ulocladium oudemansii provides protection from pathogens to fruit, blossoms, and plant tissue.
- Can be used in conventional or organic growing
- Easy to apply and leaves no residue
- Non-invasive and poses and no threat to living tissue
- Exempt from residue tolerances, making it an excellent tool for resistance management programs
- Using with a non-ionic surfactant or spreader sticker is recommended
- DO NOT apply through any type of irrigation system
- 4-hour REI (Restricted Entry Interval) and a 0-day PHI (Pre-Harvest Interval)
- Stable at room temperature for up to 12 months - no refrigeration needed
- Makes an exceptional addition to any Integrated Pest Management (IPM) program
Use the CRD Botrytis Test Kit to confirm the disease and test regularly for early intervention.
Botrystop WP can be applied to long list of crops grown in fields, orchards, nurseries and high tunnels. Some of these crops include berries and small fruits, edible flowers, grapes, hemp, ornamentals, pome fruit (apples, pears, etc.), stone fruits (cherries, peaches, plums, etc.), strawberries, tobacco, tree nuts (almonds, etc.) and vegetables.
This Product Controls These Pests or Diseases: Gray Mold (Botrytis cinerea), Botrytis Leaf Blight (Botrytis squamosa)*, Botrytis Neck Rot (Botrytis allii), Brown Rot and Blossom Blight (Monilinia spp), Jacket Rot and Green Fruit Rot (Botrytis cinerea, Monilinia spp, Sclerotinia sclerotiorum), Sclerotinia Head and Leaf Drop*, Sclerotina Stem Rot and Erwinia amylovora. Please refer to the manufacturer's label under the DOCS tab for more information, including crop specific diseases.