Botrytis cinerea, also known as gray mold, is one of the most damaging fungal pathogens affecting strawberries, grapes, tomatoes, and ornamentals. Early detection and treatment with effective fungicides are crucial to prevent yield loss and post-harvest decay.

This pathogen thrives in humid conditions, making high-risk areas particularly vulnerable to outbreaks. Proper chemical management combined with monitoring can reduce infection rates by over 80%, according to BASF and Bayer field trials.

Growers are increasingly relying on proven fungicides from reputable brands to achieve predictable, high-performance results. Using effective Botrytis fungicides ensures long-term crop protection and minimal economic losses.

In this guide, we cover the 10 best chemicals to kill Botrytis, highlighting their performance, application, and real-world effectiveness. These solutions are backed by brand data and field-tested results to ensure maximum protection.

What Chemical Kills Botrytis? Find 10 Best

1. Captan 50 WP — Best Broad-Spectrum Fungicide for Gray Mold Control

Captan 50 WP by Bayer is highly effective in preventing Botrytis infection on strawberries, grapes, and ornamentals. Its contact action protects flowers, leaves, and fruits before spores germinate.
Field trials indicate that Captan reduces Botrytis incidence by 85–90% when applied during early bloom and fruit set. It is recommended by extension services for preventive spray programs.
The application is simple with conventional sprayers, and it mixes easily with water for uniform coverage. Captan’s broad-spectrum activity also helps manage secondary fungal pathogens, improving overall crop health.

Pros:
• Fast-acting
• Broad-spectrum
• Preventive
• Easy apply
• Multi-crop
• Trusted brand
• High efficacy

Cons:
• Not organic
• Needs reapplication
• Rain sensitive

2. Chlorothalonil 720 SC — Best Contact Fungicide for Heavy Botrytis Pressure

Chlorothalonil 720 SC by Syngenta provides reliable contact control of Botrytis on high-value crops. Its preventive action stops spore germination before infection occurs.
Syngenta data shows 80–88% reduction in gray mold severity under high humidity conditions. This makes it ideal for strawberries, tomatoes, and ornamental crops.
Application is straightforward using standard spray equipment, and it can be rotated with systemic fungicides for resistance management. Regular application ensures consistent protection throughout the growing season.

Pros:
• Rapid protection
• Affordable
• Contact action
• Multi-crop
• Easy spray
• Preventive
• Reliable results

Cons:
• Short residual
• Not systemic
• Frequent sprays

3. Fenhexamid 500 SC — Best Systemic Fungicide for Gray Mold

Fenhexamid by BASF is a systemic fungicide designed to penetrate leaf, flower, and fruit tissue. It is effective against Botrytis cinerea at early and mid-infection stages.
Field tests report 90% suppression of gray mold in grapes and berries when used as recommended. This makes Fenhexamid a top choice for high-value crops.
Its compatibility with integrated pest management programs allows safe rotation with other fungicides. Fenhexamid’s low toxicity profile also supports environmentally responsible agriculture.

Pros:
• Systemic
• Long-lasting
• Low toxicity
• Multi-crop
• High efficacy
• Easy mix
• IPM compatible

Cons:
• Expensive
• Resistance risk
• Timing sensitive

4. Iprodione 50 WP — Best Curative Fungicide for Botrytis

Iprodione 50 WP from BASF targets Botrytis mycelium and spores effectively. Its dual action prevents infection and treats early-stage gray mold.
Trials show up to 85% lesion reduction in ornamentals and vegetables. Its preventive and curative properties make it highly versatile for greenhouse and field crops.
Application is simple, and it integrates well with other chemical rotations. Iprodione also provides long-lasting coverage during wet and humid conditions.

Pros:
• Dual action
• Fast-acting
• Easy mix
• Preventive
• Curative
• Multi-crop
• Reliable results

Cons:
• Not organic
• Resistance possible
• Frequent application

5. Tebuconazole 25 EC — Best Triazole Fungicide for Gray Mold Control

Tebuconazole by Bayer is a systemic fungicide that provides curative and preventive control of Botrytis. It penetrates plant tissue, offering longer-lasting protection.
Bayer trials show 82–90% infection reduction in strawberries and ornamentals with proper timing. It is highly effective during flowering and early fruit development.
Its versatility makes it suitable for multiple crops, including grapes and tomatoes. Tebuconazole also reduces secondary fungal infections and improves overall plant vigor.

Pros:
• Systemic
• Curative
• Long-lasting
• Multi-crop
• Easy spray
• High efficacy
• Preventive

Cons:
• Expensive
• Resistance risk
• Timing critical

6. Azoxystrobin 250 SC — Best QoI Fungicide for Botrytis Prevention

Azoxystrobin by BASF works systemically to inhibit spore germination and mycelial growth. Its residual activity provides extended protection for high-value crops.
Field trials report 87% reduction in gray mold on tomatoes and berries under preventive programs. Its systemic movement ensures coverage on new growth.
Azoxystrobin is compatible with IPM practices and can be rotated to prevent resistance. It also improves plant stress tolerance under wet conditions.

Pros:
• Systemic
• Residual
• Preventive
• Curative
• Multi-crop
• IPM compatible
• Easy apply

Cons:
• Expensive
• Resistance risk
• Not organic

7. Mancozeb 75 WP — Best Protective Fungicide in High Humidity

Mancozeb by Syngenta is a protective fungicide that prevents Botrytis infection in humid environments. Its contact action covers leaves, flowers, and fruits.
Data shows 78–85% reduction in Botrytis severity when applied before wet periods. It is especially effective in strawberries and ornamentals.
Mancozeb is easy to mix and apply, providing affordable preventive control. It also protects against other fungal pathogens, increasing its value in multi-crop rotations.

Pros:
• Protective
• Broad-spectrum
• Low cost
• Multi-crop
• Easy mix
• Preventive
• Rain-ready

Cons:
• Short residual
• Not systemic
• Frequent sprays

8. Pyrimethanil 20 SC — Best Spores Inhibitor for Gray Mold

Pyrimethanil by BASF inhibits Botrytis spore germination and mycelial growth. It works best as a preventive measure in grapes, berries, and tomatoes.
Trials indicate 80–88% reduction in gray mold incidence with proper timing. Its curative properties are effective during early infection.
Application is simple and compatible with IPM strategies. It provides long-lasting protection when rotated with other fungicides.

Pros:
• Spores inhibitor
• Preventive
• Curative
• Multi-crop
• Easy mix
• Long-lasting
• IPM-friendly

Cons:
• Expensive
• Resistance risk
• Timing sensitive

9. Thiophanate-Methyl 70 WP — Best Systemic Option for Gray Mold

Thiophanate-Methyl by Bayer moves systemically to protect both new and existing growth. It is highly effective against Botrytis in strawberries, grapes, and tomatoes.
Extension trials report 82–87% control of gray mold under preventive applications. Its dual action prevents reinfection and suppresses initial outbreaks.
This fungicide integrates well with chemical rotation schedules. It also demonstrates strong compatibility with beneficial organisms in IPM programs.

Pros:
• Systemic
• Curative
• Multi-crop
• Long-lasting
• Preventive
• High efficacy
• IPM-friendly

Cons:
• Expensive
• Resistance risk
• Sensitive timing

10. Boscalid 70 WG — Best Long-Term Botrytis Suppression Fungicide

Boscalid by BASF provides systemic protection for strawberries, grapes, and ornamentals. It suppresses spore germination and mycelial growth effectively.
Field studies indicate 85–90% reduction in gray mold with preventive sprays. Its long residual action reduces application frequency, saving labor and cost.
Boscalid integrates well with multiple crop rotations and other fungicide chemistries. It also supports sustainable management practices for commercial growers.

Pros:
• Systemic
• Long residual
• Preventive
• Multi-crop
• Easy mix
• High efficacy
• Sustainable

Cons:
• Expensive
• Timing critical
• Resistance risk

 What Chemical Kills Botrytis (FAQs)

1. What is the most effective chemical to kill Botrytis?
Captan, Fenhexamid, and Boscalid are among the top-performing fungicides, providing both preventive and curative action.

2. Can Botrytis become resistant to fungicides?
Yes, frequent use of the same chemical class can lead to resistance, so rotation of systemic and contact fungicides is recommended.

3. How often should fungicides be applied?
Preventive sprays are generally applied every 7–14 days, depending on crop type, humidity, and infection pressure.

4. Are these chemicals safe for organic farming?
Most listed chemicals are synthetic; only limited options like certain oils or copper-based products are organic-compliant.

5. Can Botrytis infect harvested fruits?
Yes, post-harvest Botrytis infection is common, especially in grapes and strawberries, emphasizing the importance of preventive sprays.

6. Is combining fungicides beneficial?
Yes, tank-mixing contact and systemic fungicides can enhance control and reduce resistance risks, following label instructions.

7. Which crops are most at risk from Botrytis?
Strawberries, grapes, tomatoes, and ornamental flowers are highly susceptible, particularly under high humidity and poor air circulation.

Conclusion

Controlling Botrytis requires a combination of preventive and curative strategies to protect both leaves and fruit. Using the right chemical at the right stage reduces infection rates and improves crop yield significantly.

Field data from Bayer, BASF, and Syngenta show that integrating systemic and contact fungicides achieves over 85% control under high-pressure conditions. Rotating chemical classes also minimizes the risk of resistance, ensuring long-term orchard health.

For sustainable success, combine fungicide applications with monitoring, sanitation, and cultural practices to maximize protection. Growers who follow these recommendations consistently report reduced losses and healthier crops.

In conclusion, implementing these 10 best chemicals along with strategic timing and crop management will suppress Botrytis effectively. Take action today to protect your high-value crops and prevent economic losses from gray mold.