Published on 04/10/2024
John van der Linden, horticultural technical specialist for Corteva Agriscience, says this is great news for both organic growers, and conventional growers who prefer to use organic inputs on fruit and vegetable crops.
The product in question is Kocide Opti, which is already well-established in the NZ market, and has earned firm favour for a technically advanced formulation, he says.
Featuring more bioavailable copper, allowing lower use rates and application of less active ingredient per hectare, Kocide Opti creates copper matrix-like complexes on the plant after application which resist washoff and give extended protection.
“The special co-formulant in Kocide Opti allows the copper crystals to adhere to the leaf surface and act as reservoirs, continously releasing copper ions in the presence of moisture, forming a protective barrier that prevents infection,” van der Linden explains.
He says while many copper products are available to NZ growers, it’s important to realise that not all are created the same, nor do they perform the same.
“The direct measure of effectiveness is not the metallic copper content alone, but the amount of bioavailable copper ions produced, as this is the component that protects from disease.
“In turn, the most effective copper compounds are the fixed coppers, which are formulated to be less soluble to reduce possible plant phytotoxic effects.”
Copper hydroxide, which is the active ingredient in Kocide Opti, is a particularly good example of fixed copper, he says. Crystals of these compounds have the largest surface area for the release of bioavailable copper ions.
The actual size of each copper particle matters too.
While copper particles of less than 1 micron are immediately available, they can cause phytotoxicity if present in large amounts and can be easily dislodged from the plant, van der Linden says.
Kocide Opti has a median particle size of 2.5 microns, maximising effectiveness and the amount of fungicide retained on the leaf, providing excellent retention after rainfall for sustained activity.
A key advantage of the formulation is less metallic copper is applied and less remains in the soil compared to other copper formulations, resulting in lower long-term environmental impact.
From October, customers will have the option to purchase the 10 kg size of Kocide Opti in new paper-based packaging.
For more detail contact your local CortevaAgriscience territory sales manager.