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Cherry Picking

A Unique Copper for Controlling Pseudomonas in Cherries

Controlling Pseudomonas syringae is of utmost importance, but ensuring the copper necessary for that control isn’t building up in soil is equally as important.
Cherry Picking

Pseudomonas syringae is a particularly harmful bacterium to cherries, resulting in bacterial blight and bacterial canker, a disease that can destroy cherry tree limbs and decrease yield and quality of the crop. A lesser-known side effect of Pseudomonas syringae in cherry trees is that the bacteria can increase the risk of frost damage to cherry trees. As a result, preventing the bacteria from spreading throughout the tree in the fall and spring will also help the tree’s health.

Controlling Pseudomonas syringae is of utmost importance, but ensuring the copper necessary for that control isn’t building up in soil is equally as important.

Some copper products on the market require rates with high copper content and this copper ends up running off into the soil or clogging sprayer nozzles as a result of being made up of copper particle suspensions. As a result, any chemistries tank mixed with copper suspensions may not be applied evenly and extra time must be spent clearing nozzles. In many cases, a build-up of copper in the soil can be detrimental to organisms that inhabit the soil, including plants.

Enter Mastercop. From ADAMA, this copper product is lower in metallic copper and has a unique make-up; once in the spray tank, rather than a suspension of copper particles, Mastercop forms a solution of copper ions. Copper ions are biologically active as soon as they hit the plant. These copper ions adhere better to leaves and trees to prevent the damaging effects of the Pseudomonas syringae bacteria to cherry trees. It also means that less copper is needed to help control bacterial blight in cherries.

Mastercop is ideal for tank mixing with other pesticides or nutrients. Since it is mostly copper ions (Cu2+) in the spray tank and, does not contain copper particulates, it mixes easily and consistently with other chemistries. “It’s like dissolving salt into water,” said Steven Eskelsen, product development representative for ADAMA. “It’s almost impossible for Mastercop to cause nozzle problems,” Eskelsen continued.

Copper is also a nutrient that cherries need, so providing copper molecules that the leaves can absorb for their nutrition could be “a side benefit of controlling the bacteria,” Eskelsen said.


Proper Application for the Best Control of Pseudomonas

Eskelsen recommends growers use Mastercop preventatively to help prevent trees from experiencing the girdling effects of bacterial canker resulting from Pseudomonas syringae and to from the tree from bacterial blight. It is important that all surfaces of the cherry trees are coated before cankers open and spread the bacteria.

In the fall, growers should spray trees with Mastercop after the first frost and before heavy rains for better adhesion and control. “Every time it rains, the copper ions protect the tree. When the leaves dry, the copper adheres to them,” Eskelsen said. The action and protection starts as soon as Mastercop is applied, with the antibacterial properties of the copper ion ready to kill Pseudomonas syringae.

Mastercop should be applied two or three times each year, with the next application in spring prior to full blossom, spraying only during early to mid-blossoming.

When tank mixing, Eskelsen recommends that other chemistries that are difficult to suspend are added to the tank first, with Mastercop as the final chemistry added, since it is easy to mix. Growers should agitate the tank well to ensure the other chemistries are suspended. It can be used in both organic and conventional growing settings as Mastercop is OMRI listed.

For more information about Mastercop, click here.