Yellowing and Spots on Tomato Leaves - Ask Extension
Recently, the leaves of my tomato plants, starting at the bottom, but moving upwards, have begun to yellow and develop spots (see attached image.) Th...
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Yellowing and Spots on Tomato Leaves #876806
Asked July 11, 2024, 11:01 AM EDT
Recently, the leaves of my tomato plants, starting at the bottom, but moving upwards, have begun to yellow and develop spots (see attached image.) The plants continue to grow and are producing fruit, although it has been slow to ripen. There is a straw mulch on top of the soil to minimize dirt splatter on the plant during rain and I also have been regularly feeding the plant with Miracle Gro for tomatoes (about every 14 days.) I also have sprayed with Neem oil to try and control pests or disease. The tomatoes are in a bed that last was planted with sweet potatoes and peppers.
Is there anything that I can do to control this, or is this something about which I should not be concerned? Thank you!
Lorain County Ohio
Expert Response
It would appear that you have Early Blight. The first sign is dark, brown spots on the lower leaves. It can than progress from the bottom of the plant to the top. This is caused by a fungus that over winters I the soil and infected plant debris. Flea beetles can spread the pathogen as they travel from the soil to the plant. Spores are carries on the wind, equipment, insects and human contact with the plants. There are cultivars that are resistant to Early Blight, but still can be infected.
Unfortunately, all infected plants should be removed. Do not add them to a compost pile as the spores can survive for several years. Copper fungicide can be used to treat the plants. As always, read and follow the label directions for application.
Remove all plant debris at the end of the growing season to limit the spread of the infection.
