Bion 500 FS

Syngenta · EPA Reg 100-1363 · Fungicide ✓ Last verified 2026-05-30

Free practice questions on this product's label, use, and safety.

Key facts From the EPA

Registration, signal word, restricted-use status and approved use sites are sourced from the U.S. EPA pesticide registry. EPA Reg. No. 100-1363. View this product's label on the EPA ↗ (EPA copy accepted July 5, 2019)

Active ingredient Pending extraction

Manufacturer Syngenta

EPA registration 100-1363

Category Fungicide

Target pests Downy Mildew

Safety & handling WARNING

According to the label From the product label

These application details were read from this product's label by our system to help you in the field. The label is the law — always confirm rates, sites and restrictions against the actual product label before mixing or applying. View the full label →

Bion 500 FS is a systemic fungicide containing 42.0% Acibenzolar-S-methyl. It is designed for early-season protection in commercial seed treatments. In cotton, it provides protection against Black Root Rot (Thielaviopsis basicola), suppresses Fusarium oxysporum f. vasinfectum to mitigate damping-off symptoms, and provides early-season protection against certain nematodes by reducing nematode fecundity. In sunflower and sorghum, it is used for early-season protection against downy mildew. The product is intended for use in commercial seed treatment operations only; it is not for use in planter or hopper box applications. When mixing, it can be used with water or other water-based seed treatments, but compatibility should be tested via a jar test first. Users should follow resistance management strategies, such as rotating with other fungicide groups. Handling requires specific PPE, including long-sleeved shirts, long pants, shoes plus socks, and chemical-resistant gloves (barrier laminate, butyl rubber, neoprene, polyvinyl chloride, or Viton).

Application rates & sites 4

Target pest	Indoor / Outdoor	Where on site	Rate	Notes
Black Root Rot (Thielaviopsis basicola)	Outdoor	Cotton seed	0.0003 to 0.0009 mg ai/seed	Seed treatment only
Fusarium oxysporum f. vasinfectum	Outdoor	Cotton seed	0.0003 to 0.0009 mg ai/seed	Suppression of damping-off symptoms
Nematodes	Outdoor	Cotton seed	0.0003 to 0.0009 mg ai/seed	Reduces nematode fecundity
Downy Mildew (Plasmopara halstedii)	Outdoor	Sunflower and sorghum seed	0.021-0.029 mg ai/seed	Early-season protection

Mixing & dilution 1

For	Where	Amount	Per	Finished strength	Notes
					Can be mixed with water or other water-based seed treatments. Use a jar test to check compatibility. If using wettable powders/water-soluble pouches, add them to clean water first and allow to disperse before adding Bion 500 FS.

PPE required Long-sleeved shirt and long pants; shoes plus socks; chemical-resistant gloves (barrier laminate, butyl rubber ≥14 mils, neoprene rubber ≥14 mils, polyvinyl chloride (PVC) ≥14 mils or Viton® ≥14 mils).

Timing & weather

Early-season protection

Use restrictions 3

For use in commercial seed treatment operations only.
Not for use in planter or hopper box applications.
Seed treated with this product must be visually identifiable from untreated seed using an approved colorant or dye.

Documents

📄 Label 📋 SDS

Previous versions (1)

Superseded: superseded (label_prev)

📄 Previous Label

Label SDS

⬇ Download PDF Download requires a signed-in customer account. Anyone can view & print above.

Versions 2026-05-30 2026-05-30 2026-05-27 · default 2026-05-27

Label text

No label text digitised for this product yet.

Reference only. Always read and follow the most current EPA-approved label on the product container. State and local restrictions may apply that are not reflected in this digitised copy. Verify the EPA registration number and revision date before use.