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Biological Fungicide


RootShield PLUS Granules and WP
  • Water dispersible granular formulation
  • Excellent tool for resistance management
  • Exempt from Maximum Residue Limits (MRL)
  • Controls: Botrytis Blight, Botrytis Leaf Blight, Botrytis Neck Rot,
    Monilinia spp. Brown Rot, Blossom Blight,
    Sclerotinia Stem Rot, Sclerotinia Head and Leaf Drop.
  • 4-hour REI, 0-day PHI

Registered for use in the USA except: AK and HI

Available Sizes: 12 lb

Resource Center

Frequently Asked Questions

What is BotryStop?

BotryStop is a preventative biological fungicide. The active ingredient consists of living spores of the fungus Ulocladium oudemansii (U3 strain) that colonize dead and senescing plant tissue. The active ingredient is a non-pathogenic, saprophytic fungus.

How does BotryStop work?

The active ingredient spores germinate into fungal mycelia that aggressively occupy the same physical space as Botrytis spp., Sclerotinia spp. and other labeled pathogens. It out-competes the pathogens for nutrients on plant surfaces and in dead and senescing plant tissue.

Why should I use BotryStop?

BotryStop is an excellent biological control that will enhance a fungal disease control program by introducing a new active ingredient, thus helping to prevent resistant populations of Botrytis spp. and other fungal pathogens above the soil.

What is the issue with BotryStop and surfactants?

BotryStop can be used with certain surfactants and not others. It is recommended to avoid those surfactants that claim to be “penetrants” or “super penetrants,” or are good at “stomatal flooding.” These types of surfactants have been known to cause spotting on foliage and blooms. When an acceptable surfactant is used it is most effective at low rates and when using low water volumes per acre for better coverage. At high surfactant rates or at high water volumes per acre, poor coverage can result from much of the spray volume moving off of the target, taking spores with it. This can potentially result in inadequate colonization of plant tissue.

Can BotryStop be tank-mixed with other products?

Yes, BotryStop can be tank-mixed with some insecticides and some fungicides. See the BotryStop compatibility sheet for more information.

What is the minimum amount of water per acre to use when applying BotryStop?

It is recommended to use at least 50 gallons per acre.

What type of application equipment can be used?

For outdoor spraying, air blast and other hydraulic spraying equipment, including air-assisted sprayers, can be used. In greenhouses, hydraulic spraying equipment, AutoFog or other cold foggers can be used. At this time, we do not recommend application through a thermal fogger including the BioPulse Fog units.

When is the best time of day to spray BotryStop?

BotryStop is best applied in the morning.

What is the best timing for BotryStop application?

BotryStop is a preventative biofungicide, so it is best applied before pathogen infection occurs. It is applied at early and late bloom for some crops and usually when conditions are favorable for disease development. Scouting and recognizing when conditions are favorable for disease can be effective indicators of when to apply.

What are the small volume rates for BotryStop?

Gallons Water 2 lb/100 gal/acre 3 lb/100 gal/acre 4 lb/100 gal/acre
1 1 tbs 9.1 grams 1.5 Tbs 13.6 grams 2 tbs 18.2 grams
5 5.5 tbs 45.4 grams 8 tbs 68.1 grams 0.7 cups 90.8 grams
10 0.7 cups 90.8 grams 1 cups 136.2 grams 1.3 cups 181.6 grams
25 1.7 cups 227 grams 2.5 cups 340.5 grams 3.5 cups 454 grams

Where is BotryStop registered for use?

As of this writing AK, HI and NY are the only US states where BotryStop is not yet registered.

What diseases does BotryStop control?

BotryStop is labeled for foliar and fruit diseases caused by Botrytis spp. (including Botrytis cinerea), Monilinia spp., Sclerotinia spp. (including S. sclerotiorum), and Erwinia amylovora.

Is BotryStop likely to cause phytotoxicity?

No. In BioWorks testing, it has shown no phytotoxicity on sensitive open blooms on ornamentals. It has been used extensively on grapes and other plants at flowering with no phytotoxicity.

What is the optimum tank pH for BotryStop?

Keep tank mixtures in the range of pH 5 – 7.

How long can I store a tank suspension of BotryStop?

Do not store overnight or for prolonged periods. It is best to mix and apply BotryStop within 4 – 6 hours.

What are the personal protective equipment (PPE) requirements for BotryStop?

Applicators and other handlers must wear a long-sleeved shirt and long pants, waterproof gloves, and shoes plus socks. Mixers/loaders and applicators, not in enclosed cabs, must wear a NIOSH-approved particulate respirator (dust mask) with any R or P filter with NIOSH-approval number prefix TC-84A; or a NIOSH-approved powered air-purifying respirator with an HE filter with NIOSH-approval number prefix TC-21C.

Is BotryStop approved for use in certified organic production?

Yes, BotryStop is OMRI listed.

Ask an Expert

If you're a professional grower and have a question, or you just want to discuss a particular issue, contact us. We'll be ready to help address your concerns via phone or email. A BioWorks team member will respond within 4 hours during normal business hours, 8AM-5PM EST. During weekends and holidays someone will respond the next business day. If you have an urgent matter, please call us at 800-877-9443 or 585-924-4362.