First year growing tomatoes from seed. I transplanted my seedlings 3 weeks ago in the open garden. Today I noticed these black spots on the leaves of a few plants. Is it a disease? It seems older leaves are more infected than younger ones.
I removed the infected leaves and I was wondering if I should spray with something to prevent spread of the pathogen. I only want to use organic treatment though. Any suggestions?
It appears to be some sort of spot virus, such as gray leaf spot, which tends to affect younger plants.
Hate to say it, but if the seedling is already sickly it's better to trash it (in the dumpster) and start over than to try a raise a diseased plant. The disease will cause the plant to not be healthy and yield much, and worse will spread to other plants. It's not a good thing to help raise the virus in your garden.
If you want to treat it, sulfur fungicide is supposed to be an organic method, I did used some on my tomato plants to get rid of some virus. The hardware store sell copper fungicide, but it is stronger and needs to be used more carefully. Or you can try using a very light mix of baking soda. The recommended dosage tends to be 1 table spoon per gallon of water. I would be very careful with the amount of baking soda though since I caused major damage on my tomato leaves before by overusing it..
The leaves also shows sign of phosphorous deficiency due to the purling, although that generally clear up once in the soil with proper nutrient.
Try to not get your seedlings leaves wet, keep the plant dry, make sure the soil have good drainage and don't allow it to get too wet.
This message was edited Apr 27, 2015 9:25 AM
Personally, I'd try to salvage it. Be sure to put some mulch around your plant and sprinkle around the plant out to the edge of the leaves with either cornmeal or dry granulated garlic like you have in your spice rack on top of the mulch. Trim off the bottom set of leaves. Feed it with some liquid molasses and fish emulsion and see what happens. Not sure if they have those products in Greece, though.
Thanks for the replies! I cut the infected leaves and sprayed with copper. We'll see how it goes.
