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Tomato blight a regular challenge – Audio

Tomato blights in the garden

Brian Hudelson, Sr. Extension Outreach Specialist
Plant Diagnostic Lab
Department of Plant Pathology
UW-Madison College of Agricultural and Life Sciences
(608) 262-2863

2:59 – Total Time
0:16 – Tomato blights likely
0:38 – Tomato blight serious commercial issue
1:20 – Wet conditions favor disease
1:46 – Send samples into lab
2:17 – How to contact lab
2:44 – Internet search for diagnostic lab
2:50 – Lead out


Sevie Kenyon: Garden plant diseases, we’re visiting today with Brian Hudelson, Plant Diagnostic Lab University of Wisconsin-Madison in the College of Agricultural and Life Sciences, and I’m Sevie Kenyon. Brian, what kind of plant diseases might our gardeners be looking at this year?

Brian Hudelson: It could be a wide variety of things that you’re looking at, certainly in vegetable gardens, which are a really popular area for a lot of people. We worry about certain leaf blights that occur on tomato plants; that’s a popular vegetable that people grow. They often times, mid-season, find out that their plants are just kind of losing their leaves often times from the bottom up.

Sevie Kenyon: Tell us a little bit about that blight, what it looks like, how it acts?

Brian Hudelson: Yeah again, usually what you start to see are little spots on the leaves. There are a couple of different fungi that can cause the problem, but you’ll start to see leaves die from the bottom heading up the plant. Eventually you’ll kind of end up with a plant that doesn’t have any leaves but still has fruits hanging on and there are a couple of very common leaf blights that will do that. There’s also what’s called late blight which is also much more serious disease, often times that will start at the top of the plant and work its way down because the spores of that organism are blown into an area often times. That’s a much more serious disease because it can have a huge impact on our commercial potato production, and also fresh market tomato production here in the state.

Sevie Kenyon: What kind of conditions favor these blights?

Brian Hudelson: A lot of wet weather, which we have been having some of this spring and we will probably continue to have that. The common blights that I talked about, the defoliate from the bottom up, often times if folks have grown tomatoes for a long time they have a lot of those fungi hanging around in little bits of old tomato debris that have filtered down into the garden soil, and so they are going to be around all the time, but when we get wet weather all of these leaf blights on tomatoes are going to be quite prevalent.

Sevie Kenyon: Brian what should people do about these conditions?

Brian Hudelson: Well we do offer a free testing service if you think you have late blight, or even if you don’t and have a tomato plant that you have some sort of leaf disease on, if you invoke the words late blight and send a sample into my clinic we will do a free diagnosis for you. We like to keep track of whether or not we have late blight in the state and there are certain variants of that particular organism and we want to keep track of which variants we have in the state because that can again impact how we control the diseases in commercial settings.

Sevie Kenyon: How do people go about finding you?

Brian Hudelson: You can check on my website, there are instructions for submitting a sample or you can certainly give my lab a call and that number is (608) 262-2863 and it’s always an option, you have a county extension office in your county. You can take a sample in the county office they may be able to identify the problem for you, if not I am a support lab for those county offices and they will send the sample down to me.

Sevie Kenyon: Is there a key word search people can do to find your lab?

Brian Hudelson: I would just look up UW-Madison Plant Disease Diagnostic Clinic, you should pop up my website.

Sevie Kenyon: We’ve been visiting with Brian Hudelson, Plant Diagnostic Lab University of Wisconsin–Madison in the College of Agricultural and Life Sciences, and I’m Sevie Kenyon.