New copper fungicide approved for use on California crops

Sep 10, 2020

High-efficiency, liquid copper fungicide from Earth Science Labs approved for use in California on walnuts, almonds, pistachios and other crops.

Rogers, Ark. – A new low-dose liquid copper bactericide and fungicide has been approved by the California Department of Pesticide Regulation (CDPR). Registered under the name Cop-Kleen™ on Aug. 3, 2020, the new fungicide is manufactured by Earth Science Labs (ESL). It is approved for use on 94 crops, including walnuts, almonds and pistachios.

Cop-Kleen is manufactured with a proprietary process that allows it to hold ionic copper (Cu++) in solution while making it fully bio-available to plants. The result is an environmentally friendlier fungicide that uses less copper than conventional copper-based formulations. This represents an advancement over older copper inputs and even today’s more sophisticated offerings.

Copper has been used as a fungicide since 1807, when French farmers started using a copper sulfate solution to control smut and bunt fungi on cereal crop seeds. Today’s copper fungicides are more active across a broader range of applications and diseases, but problems still remain. One of them is getting copper efficiently to infection sites.

“Holding copper in solution and getting it into direct contact with pathogens often presents a challenge” said Nenad Filajdic, Product Development Lead for ESL’s Agriculture division. “Even modern formulations tend to require a higher percentage of metallic copper to control diseases than is ideal. In addition to the cost of higher copper inputs, some of that excess copper can make its way into the environment.”

Filajdic shared recent field studies of Cop-Kleen that show how it performs against other copper-based fungicides. “Cop-Kleen achieved equal control of almond blossom blight and walnut blight with 5-20% of the metallic copper used by standard copper-based products,” Filajdic said. “We are also seeing improvements in durational control because Cop-Kleen penetrates plant tissues. That means no residue on leaves and less risk of wash-off from rain.”

Earth Science Laboratories Inc. manufactures Cop-Kleen in Nebraska for agricultural use as an algicide/bactericide/fungicide. Cop-Kleen is approved by the CDPR for use on walnuts, almonds, pistachios and other crops. Cop-Kleen distributors in California include Ag Water Chemicals. Visit for more information.

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