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Is copper sulfate organic?

Posted by AnnaFL z10a FL (My Page) on
Sun, Jul 10, 05 at 17:15

I have a mango tree that was new last year. I've been told that unless you spray the inflorescences with copper sulfate until the mangoes are golf-sized, that there will be no fruit. I decided that I would be satisfied with low yield and did not spray at all. At first there were quite a few mangoes, but as soon as the first summer rain came, the anthracnose and powdery mildew, sooty mold, took over and all rotted and fell. I do want mangoes next year and need to find an organic way to keep them. Every nursery I've asked has recommended copper sulfate products. What do you think?


Follow-Up Postings:

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RE: Is copper sulfate organic?

Many copper sprays are approved for Organic crop production. They can kill some beneficials though so spraying is recommended later at night when beneficials are not as active.

I would look for the Copper spray that is made by Safer's, it doesnt have any synthetics added to the formula and is available at most garden centers, even some Lowes and Home Depots carry it now.

Many copper sprays have a "surfectant" to assist with the spray sticking to the plants and foliage, thats where the synthetics usually come in and the Organic status goes out.

I would also recommend the spray and not the dust, usually associated with Bordeaux mixes (containing lime) but can be confusing for a first time user.


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RE: Is copper sulfate organic?

Thanks, termater. I will look for the safer's copper spray. My favorite nursery has quite the section of organic stuff, so maybe they will have this product. Is there a difference between copper spray and copper sulfate spray? It sounds like the surfactant is the worst part of they spray, but is the sulfate part ok to use? If I end up using it I will definitely use it in the evening. I try hard to keep my honeybees happy.


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RE: Is copper sulfate organic?

copper sulphate is a wettable form of copper made by treating copper oxide w/ sulfuric acid - has many uses, and any spray called "copper spray" will be copper sulphate - shouldn't bother the bees if you don't directly spray it on them, maybe not even then, tho they may turn green :)

Bill


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RE: Is copper sulfate organic?

Yes,

There is a difference between coper sprays.

Bordeaux mixture is an outstanding fungicide and bactericide that has been used for decades to control some diseases of tree fruits and nuts, vine fruits, and ornamentals. The ability of Bordeaux mixture to weather the fall, winter, and spring rains and to adhere to plants makes it an excellent choice for a winter fungicide.

If Bordeaux mixture is applied in spring after the tree breaks dormancy, use weaker, more dilute formulations of the mixture to reduce the risk of plant injury. The application of Bordeaux during hot weather may cause yellowing and leaf drop. Leaf burn may occur if rain occurs soon after a Bordeaux application. To reduce the chance of leaf burn, add 1 quart of spray oil for every 100 gallons of spray mixture.

Fixed copper fungicide (tribasic copper sulfate, copper oxychloride sulfate, cupric hydroxide) sprays also control some of the same disease-causing organisms as Bordeaux mixture. While fixed copper sprays are much easier to prepare, they are far less persistent and will not withstand winter rains as well as Bordeaux mix.

They are most effective and are a better choice to use in spring after the trees have broken dormancy and tender leaves are exposed. To be effective for certain pathogens such as the leaf curl fungus, the fixed copper compound must contain at least 50% copper. With all Bordeaux and fixed copper sprays, thorough coverage is essential to give plants the desired protection from disease-causing pathogens


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RE: Is copper sulfate organic?

I found this now in 2006...so maybe it won't show up. But I have been trying to findout the same thing..What I saw on google is that the Bordeaux mixture ins NOT ORGANIC...copper without sulphates is what one should look for for Organic...my search is on. Martha/Zucchini


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RE: Is copper sulfate organic?

Masterscottage, welcome to GardenWeb. Your question is not on the topic of mold on mangoes. If you want to get an answer to your specific question, you should post a new message.

I would avoid spraying copper sulfate under all conditions. If the plant can't survive and fruit in your area without such extraordinary approach, then it is simply not suited to your area. I've seen mangoes growing untended in the wild and they have so much fruit you wonder how they stay upright.

I would try all the organic methods first. The very first thing to be sure of is that your soil is full of microbes. If you have sprayed your tree with copper sulfate, then your soil has been sterilized from the wash off that tree. You'll need to apply compost possible for a long time to get that CS out of there. I would also liberally apply ordinary corn meal all under the canopy of the tree. Corn meal has been shown to be effective at reducing fungal disease in organic applications. Apply at a rate of 20 pounds per 1,000 square feet. I would do it every other month all year round in your area. As for a spray I would alternate spraying one week with any kind of milk and the next week with liquid seaweed. Spray the entire canopy of the tree. You might need a special sprayer for trees. Be sure to get the entire trunk, all the limbs, and the tops and bottoms of all the leaves and fruit.

Also be careful what you wish for. Mango is a tree that ripens all its fruit on the same day. If you get a full crop, you will have to deal with hundreds of pounds of ripe fruit at one time. If you don't get it all picked, the next day or two it will all be on the ground.


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