Tomato Plant Problem - Ask Extension
I have a tomato plant problem where the plants are healthy until about 8-10” tall then start to go bad. I have attached photos of plant 1 where the...
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Tomato Plant Problem #602359
Asked October 14, 2019, 12:15 AM EDT
I have a tomato plant problem where the plants are healthy until about 8-10” tall then start to go bad. I have attached photos of plant 1 where the problem is progressed and will later send photos of plant 2 where the plant is just starting to turn, both are heirlooms.
Plant 1a photo – general view
Plant 1b photo – underside of leaf
Plant 1c photo – close-up of leaf
I live in Thailand but the seeds are from the States (Territorial Seed Company). This has happened on several different plantings; I have tried changing where I plant them to different locations to see if it is a localized problem. I also have tried them in hoop houses. This last planting I have not seen any bugs (other plantings I have battled thrips and white flies).
Appreciate any guidance.
Thanks & Regards,
Brent
County Outside United States
Expert Response
Thank you for your question, Brent. It is difficult to diagnose leaf problems without a microscope and knowledge of the pathogens present in the region, neither of which we have from this distance. However, here is an excellent diagnostic tool (for common tomato issues in the States) that you can use to compare photos from: http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomLeaf/TomLeafKey.html#Septoria
Good luck!
Thank you for this excellent leaf problem summary tool Kristena; lots of good information to reference and digest. I have put together something similar from articles on the internet but this one seems much more complete.
It looks like it could be a couple of these pathogens and not certain which it is. It is starting on the new growth which narrows it down. I do have a USB microscope and added photos from same. Took the top of leaf photo where there was still some green remaining on the leaf and the underside where there was full necrosis. It rained last night which is why the leaf looks wet in close-ups. This help at all?
I am beginning to think based on your link that it is from my soil. I bought a truck load of compost and truck load of cow manure (have 10 acre farm) and layered these and let sit. Both products are not sterilized. This is my common factor to all my plantings but my large varietal tomatoes seem to get hit by this every time, cherries seem to tolerate better. Any other advise is appreciated.
Thanks again, Brent
Brent: These are wonderful photos! My first thought was that it is cercospora, but the leaves do not have the traditional pattern on the leaves. I want to reiterate that the leaf problems described in the Cornell tool are limited to pathogenic and abiotic actors observed in the States. Although shipping and trade now spread diseases and insects among the continents, some may still be localized.
You suspect soil is the issue. Do you have local soil testing labs? Do you have an agricultural teaching university resource nearby? While you are looking, I will try to get input from our diagnostic lab (backed up!).
Hi Kristena,
Thanks for the quick response. One of the difficulties of living in Thailand is finding things. This includes support for these kind of issues, thus my reaching out to you.
I may have jumped the gun with the soil suspect. I did find 2 dead thrips (after checking about 6 leaves under the microscope) and now think I may have TSWV. Many of the TSWV pictures on the internet look similar to my plants. I also looked at cercospora and those photos were not as close a match. I have also had a case of curly top and had to remove all my plants so fighting small insects. Appreciate to hear what the diagnostic lab has to say.
Two questions: 1. Does curly top, cercospora or TSWV contaminate the soil or can I replant in the same area without concern of picking up these viruses from the soil? 2. The tomato diagnostic system page is a great resource, do you have similar for melons. (My melon leaves are spotting, have hit them with hydrogen peroxide after it rains but maybe some other issues going on.)
Thanks again for your assistance, great stuff.
Brent
These are not all viruses, most of which are spread by vectors (insects). Here is an article on leaf spot, a fungus whose spores can live in the soil: https://cdn.shopify.com/s/files/1/0145/8808/4272/files/A2606.pdf
Curly top is a virus: http://entoweb.okstate.edu/ddd/diseases/curlytop.htm
TSWV is a virus: http://ipm.ucanr.edu/PMG/r783102211.htmlh
Here is an article on leaf diseases of cucurbits: https://ag.umass.edu/vegetable/fact-sheets/cucurbits-leaf-spots
Good luck!
Thank you Kristena. More good info to consider.
Off to rip out my tomatoes. Trying to find where to buy seeds with Sw-5 gene, internet search has begun.
I will drop a note later with successes and failures.
Regards, Brent
Thanks, Brent. I have been so fortunate in answering Ask an Expert questions to ‘meet’ people from all over the world who have found this resource. I get to do research, learn about areas too numerous to mention, and appreciate how little I know! And, as your experience illustrates, learn how advanced the US educational system is, compared with ‘Third World’ countries. I also suspect that you cannot grow all plants in all regions of the world. There are reasons some plants are deemed “native,” which has nothing to do with the arrival of ‘aliens’ from afar. Good luck, and let me know “how thou garden groweth.”
