What’s wrong with my tomato plants? TMV?

Question: What’s wrong with my tomato plants? I’m not sure if it’s sun scald, insect damage, nutrient deficiency, or a mosaic virus. It only started appearing in the last few weeks, after fruit was set. I noticed black mite-like bugs on the pictured plants (but not other plants) earlier in the season and took care of them with a strong hose blast and neem oil. The current problem starts with a fading, rust colored or speckled bleaching of the leaves, which progresses to yellowing, wilting of the affected leaves, and the eventual death of the affected leaves. Stems seem fine. I planted these tomatoes from seed with new soil this year in a pot I had used last year. Variety is burpee veranda red hybrid, unsure if TMV/ToMV resistant. I have similar leaf discoloration on zucchini, marigolds, and dahlias, but peppers, cornflowers, and cucumbers unaffected so far. All plants being grown in fairly close proximity in separate containers. I use neem oil as a pesticide and miracle grow powder (mixes into water) fertilizer. Do I need to destroy affected plants? They don’t seem that sick, but I don’t know if this is an early sign of a bigger issue.

responder: The Question Asker Replied June 27, 2024, 8:33 AM EDT
response: Here are more pictures of affected tomatoes:

responder: The Question Asker Replied June 27, 2024, 8:34 AM EDT
response: Here is a neighboring tomato plant in a different pot. It seems less affected.

responder: The Question Asker Replied June 27, 2024, 8:34 AM EDT
response: Nearby squash (one normal leaf, one affected)

responder: The Question Asker Replied June 27, 2024, 8:35 AM EDT
response: Affected marigolds next to the squash:

responder: The Question Asker Replied June 27, 2024, 8:35 AM EDT
response: Affected squash:

responder: The Question Asker Replied June 27, 2024, 8:36 AM EDT
response: Tomato on other side of deck (~6’ away?) that is discolored but has not experienced leaf death

responder: The Question Asker Replied June 27, 2024, 8:37 AM EDT
response: And one more picture of the tomato plant plus a squash plant that’s next to that tomato plant

responder: The Question Asker Replied June 27, 2024, 8:47 AM EDT
response: Sorry for all the replies - I couldn’t fit the photos in fewer posts.  I’m concerned this is either a mosaic virus that affects nightshades and cucurbits generally, but also I don’t want to destroy my entire garden if this is actually sunscald or nutrient deficiency. The timing in the season seems wrong for a mosaic virus, but broad variety of plants affected and leaf discoloration seem to match mosaic virus. All plants doing very well considering heat stress and whatever this issue is - none have completely died from this. All plants but the dahlias were grown from seed in new soil, in a mix of new and old pots. Dahlia plant purchased in current pot. Most were started indoors under grow lights and moved outside in April or May. All get neem oil for insects and standard miracle grow fertilizer about once a week, maybe a little less. None of the plants are new.

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 27, 2024, 12:31 PM EDT
response: Hi- based on the photos we think you may have a significant two-sotted spider mite population. Use a hand lens or magnifier to closely examine the undersides of leaves for signs of small mites walking around along with their eggs. You may also observe fine, white webbing.  Mites love hot, dry weather and can produce many generations during the growing season. They don't like wet, humid conditions. Spray your plants in the morning to discourage and dislodge mites. The injury to your plants is significant so spraying with insecticidal soap or horticultural oil, especially during hot weather, could exacerbate the damage. You can also wipe the mites off leaf undersides with a soft, damp cloth.  If you can reduce the population and feeding you may get a decent tomato harvest. Keep plants well-watered and fertilize as needed. Consider moving containers to a spot where they will receive late afternoon shade. This will reduce heat stress to the plants and spider mite activity.  There may be other sucking insect pests- leafhoppers, thrips, aphids, whiteflies- that are feeding on your marigolds and dahlias. Jon

responder: The Question Asker Replied June 27, 2024, 1:05 PM EDT
response: Thank you so much!! I am incredibly relieved that it’s not likely a mosaic virus. Bugs I can fight (even if I can’t see them). if the plants are too damaged for horticultural oil, is spraying the plants with a strong hose the best method for removal? Or should I not try to remove the mites and instead focus on reducing the other sources of stress to the plants (heat, sun)?A follow up question: I have noticed spotted lanternfly nymphs on my squash plants. I reported them because they’re an invasive species, but I was not expecting them to damage my plants since I read they feed on trees mostly. Could they be causing the damage to those plants? Thanks again!! I am very grateful for your help!

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 27, 2024, 1:57 PM EDT
response: Hi- 1. yes, sprays of water from a hose to tops and bottoms of leaves would be helpful (daily or several times per week). Spray early enough in the day so foliage dries by late afternoon. 2. SLF adults and nymphs will be seen on many different plants. They are not known to feed on any vegetable plants. Jon

responder: The Question Asker Replied June 27, 2024, 8:41 PM EDT
response: Thank you so much!! I am incredibly relieved that it’s not likely a mosaic virus. Bugs I can fight (even if I can’t see them). if the plants are too damaged for horticultural oil, is spraying the plants with a strong hose the best method for removal? Or should I not try to remove the mites and instead focus on reducing the other sources of stress to the plants (heat, sun)?A follow up question: I have noticed spotted lanternfly nymphs on my squash plants. I reported them because they’re an invasive species, but I was not expecting them to damage my plants since I read they feed on trees mostly. Could they be causing the damage to those plants? Thanks again!! I am very grateful for your help!