By Deborah J. Meier, Ph.D., Technical Development, Kocide® LLC
Q. What is the best way to mix copper if I’m using it alone or with other products?
A. Copper products either are dry or liquid formulations. The majority of products used in tree nut crops are dry formulations. Start first with a quality copper product like Kocide® 3000 which is known for its superior formulation – it quickly disperses when poured into the spray tank and sprays cleanly. To maximize your copper application performances follow these steps when adding copper to your spray tank:
- Fill the spray tank one-half full with clean water. If pH needs to be adjusted, adjust with buffering agent prior to addition of copper product (and any other products).
- Slowly pour dry products into tank while hydraulic or mechanical agitation is operating (do not dump or allow product to pile up on top of the water).
- Note: Adding dry copper products slowly allows the product to more completely go into suspension. Allow the copper product to be fully mixed before adding other products.
- To achieve compatible tank mixtures, add products in the following order and wait for mixing to occur before adding the next product.
- Dry flowables (DFs, WDGs) (I recommend Kocide® 2000 or 3000)
- Wettable powders (WPs)
- Liquid flowables (SCs, SEs)
- Emulsifiable concentrates (ECs)
- Adjuvants and surfactants (spreaders, stickers, etc.)
- If compatibility is in question, use the Compatibility Jar Test before mixing a whole tank or contact your chemical supplier.
- Observe all precautions and limitations on the labels of all products used in mixtures.
Q. Are there other factors to consider prior to or after preparing my tank mix to get maximum performance out of my copper sprays?
A. Yes. First think about your orchard and why you are using copper. Always apply copper as a protectant and do full orchard sprays. Know your orchard’s history and utilize scouting and modeling programs. Also, consult extension announcements and bulletins regarding disease pressure in your crop to help determine your spray program. For maximum copper performance, follow these guidelines:
- DO NOT apply when slow drying conditions prevail.
- DO NOT apply if it is likely to rain before the spray is dry.
- DO NOT apply to wet crops.
- DO NOT apply to copper sensitive crops or cultivars.
- DO NOT apply in spray solutions having a pH of less than 6.5 as phytotoxicity may occur.
- DO NOT apply when temperatures exceed 95o F.
Kocide 3000 and Kocide 2000 are excellent copper formulations for use in tree nut production. Kocide products have been tested and proven reliable making them the trusted brand leader in copper fungicides.
Always read and carefully follow product label directions.