KOCIDE OPTI FUNGICIDE
- APVMA no.
- 63216
- Registrant
- CORTEVA AGRISCIENCE AUSTRALIA PTY LTD
- Formulation
- WATER DISPERSIBLE GRANULE
Kocide Opti Fungicide is a water-dispersible granule (WG) formulation containing copper present as cupric hydroxide (300 g/kg). As a broad-spectrum protective fungicide, it forms a preventive barrier on plant surfaces, inhibiting fungal spore germination before infection can become established in the crop canopy.
In viticultural spray programmes—from early season shoot development through to canopy maintenance across regions such as the Sunraysia, Riverland, Hunter Valley, and Yarra Valley—cupric hydroxide provides foundational protective control against key leaf and fruit diseases such as downy mildew. Its granular formulation offers efficient measuring, handling, and mixing performance in the spray vat.
Positioned primarily as a contact protectant, Kocide Opti is best applied in advance of weather conditions that favour pathogen development. It fits cleanly into integrated pest and disease management (IPDM) schedules, offering a reliable multi-site foundation that helps safeguard systemic chemistries against resistance pressure.
Active constituents
- COPPER (CU) PRESENT AS CUPRIC HYDROXIDE300 g/kg
Registered uses
| Crop | Pest or disease |
|---|---|
| Grape | Downy mildew |
Withholding period
WHP: DO NOT HARVEST FOR 1 DAY AFTER APPLICATION.
The registered withholding period specifies: DO NOT HARVEST FOR 1 DAY AFTER APPLICATION. This requires a complete 24-hour interval between the completion of spraying and the commencement of crop harvest. Ensure all application dates and times are recorded in your vineyard or farm spray diary to demonstrate compliance prior to picking. For export market considerations or processing requirements, verify specific trade guidelines with your industry body, and always refer to the approved product label.
Mode of action
Cupric hydroxide acts as a broad-spectrum, multi-site contact protectant (FRAC Group M01). Upon application, copper ions (Cu2+) are released into moisture films on the leaf surface and absorbed by germinating fungal spores. Once inside the pathogen, copper ions disrupt multiple enzyme systems and denature essential structural proteins, effectively stopping spore germination and germ tube elongation. Because the chemical functions strictly as a surface barrier without systemic movement, thorough canopy coverage is required to maintain protection.
Resistance management
Cupric hydroxide belongs to FRAC Group M01. Due to its multi-site mode of action attacking multiple fungal metabolic pathways simultaneously, the risk of target pathogens developing resistance is inherently low. To maintain robust disease control and preserve the life of other fungicide classes, growers should integrate copper applications into an alternating or block-treatment schedule with systemic fungicides from different mode-of-action groups throughout the season.
Tank-mix compatibility
Cupric hydroxide requires careful consideration when evaluating tank-mix partners. Mixing copper with acidifying buffers or acidic spray mixtures increases soluble copper levels in the solution, significantly heightening the risk of foliage burn or fruit russeting. Caution is also advised when combining with foliage oils or applying during periods of extreme heat, slow drying conditions, or onto soft young flushes. Always perform a physical jar compatibility test and refer to the approved product label for detailed mixing sequences and restriction warnings.
Handling and environment
When handling, preparing, and applying the product, operators should wear the recommended personal protective equipment (PPE) detailed on the container label, including protective eyewear, gloves, and coveralls. Copper compounds can present a hazard to aquatic life and non-target vegetation if allowed to drift or wash into waterways. Ensure application equipment is calibrated correctly and operated under appropriate weather conditions to minimise spray drift. Always consult the APVMA-approved label for specific handling statements, re-entry guidance, and environmental safety precautions.
Common questions
- When should Kocide Opti be applied for downy mildew management?
- Applications should be made protectively before infection conditions occur, ideally prior to rainfall or high-humidity events that trigger fungal spore germination. Consult your local disease monitoring services and check the approved label for specific timing guidelines.
- Why is complete spray coverage so important with copper fungicides?
- Cupric hydroxide is a contact protectant that remains on the outer plant tissue and does not move systemically through the plant. Any newly exposed foliage, leaf undersides, or fruit bunches left unsprayed remain vulnerable to fungal spore infection.
- How does copper fit into a multi-site resistance management plan?
- Because FRAC Group M01 fungicides disrupt multiple fungal enzyme systems, fungi are extremely unlikely to select for resistance. Using copper in rotation or combination with single-site systemic fungicides helps protect those systemic options from resistance build-up.
- What should I check before tank-mixing Kocide Opti with other spray products?
- Check that the tank-mix partner does not severely acidify the spray solution, which releases excess soluble copper and risks phytotoxicity. Verify compatibility warnings on both product labels and conduct a small jar test prior to broad-scale mixing.
- Where can I find specific application rates and water volume recommendations?
- Application rates, diluent volumes, and canopy-tailored water rate instructions are stated explicitly on the APVMA-approved product label attached to the container. Always read and adhere to the approved label directions before application.