Knowledgebase

Tomato Disease Analysis #844890

Asked August 09, 2023, 11:36 AM EDT

Good morning, Does the extension have a service available to diagnose plant diseases? If so, how much does that run? I have some sort of tomato wilt that's been occurring for the last couple of years, and getting worse. I can't figure out if it's Verticillium, Fusarium, or Bacterial Wilt. This year I'm going to lose about 60% of my tomato plants, despite treating three times throughout the season this year with antifungals and bordeaux mixture. The bordeaux mixture provided marginal success last year, but the plants are unresponsive this year. I can also provide photos as needed.

Ingham County Michigan

Expert Response

Hi Jason,
Yes, please attach photos, including close up of leaves that are starting to show signs of decline. Also the history of:
when you applied the fungicides
how you water( overhead or at the base?)
when you water( early, mid or late day?)
And the varieties of the tomatoes that you grow that have problems. 
Do you rotate your tomato crop to a location that didn’t grow solanaceous plants in the last 3 years?

You may attach 3 pictures at a time. If you have more, save the 3 you attached, then go back into your question and do a new update with three more photos. Each photo must be 8mb or less in size.

I will watch for your updates andsend all along to one of our vegetable experts.


Thank you for your question!   Laura S.     Michigan State University Extension Advanced Master Gardener Volunteer You may also contact the toll free MSU Extension lawn and garden hotline at 1-888-678-3464 with your gardening questions or visit www.migarden.msu.edu for Smart Gardening resources. Replied August 09, 2023, 2:08 PM EDT
Good evening,

I have included 3 photos of a single variety of tomato plant.
1. Variety - Cherokee Purple Heirloom
2. History of Fungicide Application - Applied once in June (Fungonil) - Twice in July (Mancozeb & Copper Sulfate mix) - Once in first week of August (Bordeaux solution)
3. Watering: Only watered during early season drought - every 3 days for an hour - drip irrigation - 4 to 5 PM
4. Mulch: partially composted maple leaves
5. Crop Rotation: Due to black walnut trees on the property, these isolated raised beds are the only place in the backyard that I can plant tomatoes. But, I tried planting a few tomatoes in the front yard (cherry and left over romasfrom last year) and there is no sign of disease in the front, only in the raised beds in back.
6. Varieties:  Last year I planted Roma heirloom in all 3 raised beds and half died from this disease in all 3 beds.  This year I tried 3 varieties resistant to both fusarium wilt and verticillium- Plum Regal Hybrid, Cherokee purple (shown in the attached photos), and Pony Express Hybrid.  
7. Disease Progression:  A single Cherokee purple started wilting first.  I pulled it immediately.  Then half of the Pony Express started wilting, followed by the Plum Regal, and finally the Cherokee Purple started wilting really bad in late July right just before I pulled out the Bordeaux treatment in early August.  Since the Bordeaux treatment the Cherokee purple and Plum Regal have worsened, but the Pony Express has improved marginally, at least as far as wilt is concerned.
Since the last application of Bordeaux, the Plum Regal and Cherokee purple have wilted worse, but the Pony Express Hybrid has begun recovering from wilt, although the lower leaves are turning yellow with brown tips.
8. Intercrops: Peppers- Hungarian Hot, California Wonder Bell, Jalapeno; Onions - Walla Walla sweet; Butternut Squash;  All intercrops are unaffected, although the greens of the onions have been flopped over since spring, but onions developed to softball size without issue.

I see that the extension provides analyses of samples, so I can send in samples too as needed. Please let me know if you need any further information or photos of the other tomato varieties.

Thanks for all of your help!



On Wednesday, August 9, 2023 at 02:08:49 PM EDT, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied August 15, 2023, 9:47 PM EDT

Hi Jason, thanks for the question.

This sudden wilting late in season is right in line with Black Walnut Toxicity.  As Black Walnut ages it can have more impact on the plants. How far away from the tree are the raised beds? Have you noticed any spots or yellowing in the leaves that are showing dead in the picture of the whole plant?  Did the sudden wilting happen after a heavy rain event?  Do the raised beds have a barrier to prevent infiltration of Black Walnut Roots? When you pulled up the plants did you examine the roots?  You can run a bacterial ooze test on parts of the stem on plants removed.  You can also look at the vascular tissue to see if it is brown indicating fusarium or verticillium.  Verticillium is much slower in progression.  Fusarium can be one sided. Bacterial wilt will most likely start at the top and Verticillium and Fusarium.  Check out the following links:

Bacterial Wilt of Tomato | Public | Clemson University, South Carolina

Black Walnut Toxicity – Wisconsin Horticulture

Fusarium Wilt of Tomatoes in a Home Garden | University of Maryland Extension (umd.edu)

Fusarium and Verticillium Wilts of Vegetables | USU

I look forward to your response.


An Ask Extension Expert Replied August 18, 2023, 8:39 PM EDT
Good evening,

The beds are near a walnut tree but do not have any material mixed in, have a bottom barrier, and are only 2 seasons old. I am careful about preventing material from mixing in.  This also happened during the first season as well before any potential contamination could have occurred from above. 

The roots are normal in appearance with no sign of root knot nematode or rotting.

The vascular tissue is brown near the base but I need to know if this is fusarium or verticillium so I know how to combat it and know what should grow here. It did come on fairly suddenly, but after a few plants showed minor wilting for a couple of weeks.  It got worse before the heavy rains.  All of the tomato varieties planted are listed as resistant to fusarium and I believe verticillium, especially the hybrids.  Each variety is, however, succumbing, but the pony express has rebounded slightly following the Bordeaux treatment.

How can I go about sending in samples to settle this once and for all?

Best regards, 
Jason Mysinger


From: ask=<personal data hidden> <ask=<personal data hidden>> on behalf of Ask Extension <<personal data hidden>>
Sent: Friday, August 18, 2023 8:39:47 PM
To: Jason Mysinger <<personal data hidden>>
Subject: Re: Tomato Disease Analysis (#0114816)
 
The Question Asker Replied August 18, 2023, 9:04 PM EDT

Hi Jason,

You can mail samples to the MSU Plant and Pest Diagnostics lab for a fee.  Sample can be mailed or dropped off at the lab.  Be sure to read the sample submission information on the website at Plant & Pest Diagnostics (msu.edu).


An Ask Extension Expert Replied August 18, 2023, 10:05 PM EDT

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