Last week my tomato vines started dying off, and now a lot of my formally...

Asked August 19, 2013, 7:58 PM EDT

Last week my tomato vines started dying off, and now a lot of my formally good tomatoes are all getting marks--it looks like Late Blight.( I saw a picture at http://www.longislandhort.cornell.edu/vegpath/photos/lateblight_tomato.htm) and that's exactly what it looks like. What do I do? Can my tomatoes be saved or do I have to dig everything up? I've just noticed my cucumber vines starting to yellow and get spots. In addition, my spaghetti squash leaves and vines are beginning to yellow--not sure if any of this is related. I took pictures of everything, but I can only upload one image.

Stark County Ohio

1 Response

Please see the notice from Sally Miller, OSU Extension Specialist for Vegetable Pathology included below. If you can provide a sample of the items that you mentioned in separate containers, and/or pictures similar to the one that you attached that would be most helpful. Please send the samples to Sally directly, as well as any pictures. Her contact information is also included in the note.

I would be happy to send/email you several links to our Ohio State University Extension fact sheets on late blight, downy mildew, etc. My contact information is included below as your local Extension office in Stark County.
Thanks for using ask an expert!

Late Blight Alert from Sally Miller-


We are experiencing more late blight outbreaks in tomatoes and potatoes this summer than in the past several years. I ask for your help in contacting the OSU Vegetable Pathology Lab when you find late blight - whether in home gardens or commercial fields. It is important that we report late blight outbreaks to the national database (usablight.org) to help not only in research efforts but also to alert others in your area.

We also ship samples to Cornell Univ. for typing. Why is this important? Strains of the pathogen vary in sensitivity to fungicides, particularly Ridomil. Ridomil is by far the best fungicide to control late blight once it has appeared in a field, and has the best curative activity of all available fungicides. However, not all late blight strains are sensitive to Ridomil, and we are trying to determine the frequency of these strains in Ohio and elsewhere in the country. So far this year we are seeing US23 in Ohio, but that has not always been the case.

So I am asking for your help in 1) notifying us when you find late blight in a new area and 2) sending us samples - stem and fruit samples with lesions hold up best during shipping. You can ship them via US Mail, UPS, etc - 2 day shipping is fine.

If you can't send samples, please text or email a photo of typical symptoms, as well as the location of the outbreak (nearest town), the type of planting (garden, field, high tunnel, greenhouse, etc.), conventional vs. organic, and variety if possible. Information on which, if any, fungicides were used and when would also be appreciated.

Please text to 330-466-5249; email to miller.769@osu.edu.

Follow me on Twitter @OhioVeggieDoc for reports on late blight, downy mildew and other serious disease outbreaks in vegetables.

Thanks,
Sally