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Saturday, June 11, 2011

Septoria/Leaf Spot on Tomato Stems: Scrape it Away!

First off, I am not sure this is Septoria. I believe it is. It is a spot disease. These plants had spots on the leaves and it looked like Septoria. All my leaves of any infected plant were cured by removing the leaves with spots and spraying the upper and lower sides of the remaining tomato leaves with my sulfur spray.

All in all I removed one plant. Leaves that had spots here and there were removed ASAP. I did spray all my plants as prevention that is standard practice for me now. They will get sprayed a minimum of 1x weekly. I am tracking if the spray does any damage. So far none noticed. All my plants are flowering and now I am seeing if the spray effects tomato production, that is will sprayed flowers turn into tomatoes.

My new experiment and I would suggest you view this as an experiment and try it out as just that... is to scrape away the spots on the stems of tomatoes. I have pictures. Scraping the spots takes off just the outer layer of the tomato stem. My theory is the spots are active and don't die off even when covered in spray. The second part of my theory is that the stem of a tomato is quite hardy and can heal. It is better to damage it and let it heal rather then leave the spots there, I think.

The concerns... Leaf spot could spread more quickly by damaging the plant and scraping the infected areas. I do know about spreading internally because Septoria or leaf spot is not a virus. It spreads externally. Wounding the plant won't introduce a virus into the plant. This is getting a bit scientific. If you count guessing as scientific.

I do three things.
  • Scrape the spots without touching the rest of the plant with my fingers or razor
  • Spray the freshly scraped spot with sulfur spray
  • Spray the surrounding leaves with sulfur spray once done with the plant

Pictures of what the process looks like.

Pictures of the spots on the stems:

These pictures will give you a good idea of what I am targeting. I actually just scraped them away.


Click to Enlarge and You Will See Spots!
Spots

A Really Good Picture of Spots on a Stem

Pictures of removed spots from  the stems if tomatoes are next. You only have to remove a layer that is thinner then a piece of clear tape. It isn't hard. There is no need to dig into the stem.

If You Enlarge This, You Will See Spots and Scraped Spots.
The above picture is my 2 foot dwarf cherries. They seemed to get it the worst.  I decided to scrape spots because of these plants. They are determinate varieties and I noticed the spots moving upward. I decided to scrape them to see if I could slow the process until the tomatoes naturally died out in July.

This plant had a lot of spots. I scraped them in stages to see how the stem would heal. It looks a mess but this was about 7-10 days ago. I have pictures of progress as of yesterday that I will post. It worked!


Freshly and Gently Scraped Stem
Scraped Stem to the Left and Spotted Stem to the Right

Scraped Stem. Notice How Shallow the Scraping Is.

Like I mentioned the above process was done about a week ago. I will update pictures of the stems as of yesterday, once I load them and all that. In short, the process worked.

Here are the spots versus the scrapes to give you an easy way to see the difference.











After the spots were scraped, I washed my hands or razor and the sprayed the wounds with sulfur spray.