My fungicide fail

I have been looking for way to control sooty blotch and flyspeck, as sooty blotch was very bad on Liberty apples that I bagged last year. I recently found a paper on controlling sooty blotch and flyspeck on apples using a mixture of methionine (an amino acid from proteins) and riboflavin (vitamin B2) along with a low dose of copper and surfactant.

This method garnered some interest around 2000 for disease treatments, but I couldn’t find much more recent on it.

The mix is 150 mg/L methionine, 10 mg/L riboflavin, 65 mg/L Cu2+, and 1 g/L surfactant.

Since I have been avoiding buying synthetics, I thought I’d give this a try. And I figured it was relatively benign since it essentially uses two health supplements, soap, and low(er) does of Cu to kill sooty blotch and flyspeck fungi. I know that they are just cosmetic diseases, but being conditioned to fruit without sooty blotch and flyspeck makes the perfectionist in me want to try to grow a perfect apple.

I applied it this morning. I probably should have done a spot spray on a couple apples to test it out first…

I am pretty sure I gave quite a few apples a toxic dose of copper. The major problem seems to stem from droplets sitting on the bottom side of the fruit for an extended period of time. I’m glad that only part of the fruit are showing symptoms. And hopefully this will just turn out to be russet, and not develop into some sort of rot or fruit drop. :frowning2:


That looks like it will be cosmetic at the worst, wait and see how it develops.


Yeah, I think it will be just cosmetic. I thinned out a Zestar apple with some scab and this ring, and it seems to just involve the skin for the most part.

I could have just used potassium bicarbonate… Sulfur is completely ineffective for me, even when impregnated in my footie bags after multiple sprays. I need to find a way to justify the big jug of Pristine…

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I was reviewing my season results tonight in the respective thread and thought I’d give an update on this. Here are two apples I pulled from my fridg eaffected by the russetting, mostly likely from soluble copper.

I ended up using Pristine fungicide a month later in July and got all perfect apples with no sooty blotch or flyspeck. Pretty amazing.

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