Tomato leaf spots and curling

Asked May 7, 2020, 12:43 PM EDT

Hello, Can you help me identify the problem affecting my tomato plants? I believe I have two separate issues, though perhaps they're connected. All the plants were all grown in both organic and non-organic potting and compost planting mixes, sewn in a raised greenhouse bed and then potted and brought into open air during nice days. 1) Leaf spots. Especially on the lower leaves of a few of my plants, the leaves are developing dry, brown spots. It appears to be the spaces between major veins in the leaf that are drying. Affected types are Sungold Orange Cherry, Black Cherry, and Little Napoli. Couldn't come across any photos online that were an obvious match to help me ID the issue, but I've attached a close-up of some of my leaves. 2) Leaves curling. The leaves do not appear to be weak or drooping—they are green and crisp—but pronouncedly curl downwards on some of my plants. On some cherry tomatoes, lower leaf stems stick out from the main stem at a right angle and then turn down (but individual leaves along the branch are not curling up nor down). On most of my Brandywines, the more obvious curl is in the newer leaves, with the new leaf stems and large individual leaves curling down almost like a fiddlehead (but otherwise appearing healthy). I've attached photos with examples of both. Only one Sungold Cherry tomato plant appears to be affected by both leaf spots and downwards curling. There appears to be no other overlap between the two issues. Can you advise what the problems may be and what I need to do with the affected plants? Thanks in advance, Cam

Multnomah County Oregon

1 Response

Your first picture looks like slug damage. Slugs and snails scrape the leaves of plants leaving damaged areas on the leaves. The scraped areas then fall out creating the irregular holes characteristic of slug damage. To confirm slug damage place a flat container with beer in the area. You should see the slugs there the next day. Slugs are nocturnal, so you don't see them often on sunny days. If you go out at night you'll find them. You can then put them into a container of soapy water to dispose them. This site has very good information on slugs and slug control with links to other information on its site, How to Identify Snail or Slug Damage http://www.allaboutslugs.com/how-to-identify-slug-or-snail-damage/.

Your second and third pictures look like physiological leaf roll, because most of the leaves on the plants look green and healthy. This occurs often in the spring especially with newly planted tomatoes. It's an unbalance of root development to leaf growth. When you plant a tomato its roots are not fully developed. It tries to put on vigorous top growth, but the roots cannot keep up with the demands of the growth. It is seen first in lower leaves and older leaves. If severe can affect all leaves. Causes are environmental conditions and include: transplant shock, heat, drought, excess water, root injury, high nitrogen fertilizer which stimulates growth, and severe pruning. To prevent physiological leaf roll harden off the plants prior to planting, choose different cultivars, maintain consistent soil moisture (mulch really helps), fertilize carefully with nitrogen to prevent overgrowth, and protect the plants from root injury. Other causes for tomato leaf roll include chemical injury with herbicides, especially 2,4-D, and viruses. Unless severe, this should not affect the fruit yield or quality. This article has a good discussion of physiological leaf roll, Why in the Heck are my Tomato Leaves Curling? http://hyg.ipm.illinois.edu/article.php?id=498.