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Welcome back my gardening friends to another focal point
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Friday episode. Let's spend just a few minutes
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together, reviewing a snippet of information, from a previous
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episode, highlighting a new topic or quickly focusing on a
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current event in the food and agriculture world.
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Let's get down and dirty. So as we move into June, the
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majority of us have gotten our tomato plants in the ground.
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If you are in the southern part of the northern hemisphere, you
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are probably well on your way to your first harvest.
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If you're a little bit further north of me than you are
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probably. We just now getting your tomato
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plants into the ground or you are anticipating being able to
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do that soon. And those of us here in West
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Central, Missouri are probably already starting to battle
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tomato diseases at based on our humidity and our rain patterns.
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So I thought today would be a good time to revisit something
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about tomato plant diseases. I covered the top eight of these
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in episode 99, so we are going to revisit that one today,
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enjoy. Now, I'm not going to hit all of
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the possible diseases that you could get on your Tomatoes.
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I'm just going to hit the eight, most common ones.
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There are honestly, so many diseases that could hit your
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tomato plants, depending on where you live.
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This would be a three-hour episode if I covered them all.
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So these are going to be the ones that I have seen and read
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are the most prevalent. Now, I've not had Direct
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experience with all of them, thankfully, but I have a lot of
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resources for my college classes and All my Growers guide, so
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I'll do my best to relay the info on the ones that I'm not
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familiar with. So you can at least get an idea
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of what to look out for and how to prevent or contain diseases
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in your Tomatoes. I would always recommend doing a
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search on your local University, extension service or plant Lab
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website for diseases that are most common in your area.
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So you're not freaking out about something that just isn't very
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common in your climate. So without further Ado, let's
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dig into the eight most common tomato plant diseases.
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First up, bacterial Wilt, bacterial Wilt.
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It's also called Southern bacterial.
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Blight is a serious disease caused by Ralph's.
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Tonyia soul in this area. Now, that last name their soul
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in a cerium tells you, this is a disease of the solanaceae is,
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right? Or tomatoes or peppers, are
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potatoes, that sort of thing. This bacteria survives in the
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soil for Periods. And it enters the roots through
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wounds made by transplanting cultivation.
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Insect feeding damage, what have you?
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This is different from the bacterial Wilt that we see in
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cucumbers and other qubits that bacterial Wilt is spread by
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insects specifically, cucumber beetles.
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This bacterial Wilt is specific to tomatoes and their other
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solanaceae cousins and rely resides in the soil.
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Now, high temperatures and high moisture.
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Speed the growth of this disease, the bacteria multiply
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rapidly inside the water conducting tissues of the
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plants. That's the xylem filling it with
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slime. So this causes a really fast
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wilting of the plant. While the leaves still stay
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green. And if an infected stem is cut
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crosswise, it's going to look Brown and you're going to have
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these tiny droplets of a yellowish ooze coming out of it.
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Yum. Control of bacterial Wilt.
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When you have infected soil, is really, really difficult.
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Rotation with non susceptible, plants like your corn, beans
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cabbage, for at least three years between planting other,
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solanaceae will provide some control.
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You do not want to use Peppers or eggplant, or potatoes,
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sunflowers or Kosmos in that rotation.
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You do want to remove all infected plant material.
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If you discover that your plants are infected.
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It though, unfortunately, there is no chemical control for this
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disease. So you might consider growing
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all of your susceptible solanaceous plants in a separate
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newly prepared Garden site. If you discover that you have
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bacterial Wilt, you want to be completely separate from your
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original garden. And then you also want to make
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sure that you thoroughly hose off all the soil from any of
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your tools that you used in the original infested beds and
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thorough way. Sterilize them before you use
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them in your new Garden site. Next on our list is early blight
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early, blight also known as alternaria leaf, spot is one
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that I am very familiar with this disease, is caused by the
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fungus, alternaria land area, and it first pops up as these
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small brown lesions mainly on the older foliage of your
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tomato, plants the spots, then get bigger and they form these
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concentric rings in a bull's eye.
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Pattern usually smack dab in the center of the disease area.
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And then the to the tissue surrounding the spots is going
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to start turning yellow, a sickly color.
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Now, here's what usually causes the biggest problem.
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If you get both high temperatures and high humidity,
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at this stage of the disease, a lot of the foliage on your plant
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is just going to be killed off plants with early.
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Blight may also get lesions on the stems that look, very
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similar to the ones on the leaves and it's sometimes Just
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causes caller rot, which is where the lesions will girdle.
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The plant right at the soil line.
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If all of this doesn't kill the plant off and it does manage to
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produce fruit, the fruit will often have really large lesions
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usually covering most of the entire fruit with those
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concentric rings. And then the infected for
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usually just drops right off the plant.
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Now this fungus survives on Infected, debris in the soil, it
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survives on seeds, it will show up on volunteer.
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Tomato plants and other solanaceous plants.
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Like potatoes and eggplants plus black Nightshade which is a very
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common weed and it is also in that same family.
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That's generally what we think is the alternate host in our
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area that holds onto the fungus until it's time to spread it.
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I'll happily to Our tomato plants that black knight shape.
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So to prevent the disease you want to use resistant or
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tolerant tomato varieties if you can and don't save seeds from
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open pollinated plants. Were infected the year before.
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Use a good crop rotation. Keep your weeds in your
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volunteer tomato, plants at Bay and use proper plant spacing to
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keep them from touching each other.
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You want that airflow mulch your plants to keep the soil from
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splashing up on onto the, the leaves and try to avoid overhead
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watering especially during very warm and human times in the
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season. Now, if you see signs of the
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disease, trim off and dispose of all of the infected lower
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branches, and And the leaves. This is one reason why I
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generally will prune my tomatoes so that the leaves and branches
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that are closest to the ground are completely removed even
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before I see signs because it's pretty inevitable.
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That we're going to get it here. If you do, end up with more
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signs of the disease, make sure you trim up and remove all of
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those affected leaves and then treat with an appropriate
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fungicide for your garden practices for me, that means a
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copper fungicide. I'm getting ready to apply my
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first round of it this week and I'll put a link in the show
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notes for what I Be using. I am very confident.
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I'll be able to nip it in the bud because, yes, I am already
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seeing signs of it on my lower leaves.
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And I am thankful this week is predicted to be a little bit
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lower in humidity, so I can trim up the plants and give them a
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good spray of that copper. So, usually, what follows
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immediately? After early blight in my garden
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is next on my list, which is sub Toria leaf spot, but it
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absolutely can be its own Standalone disease in your area.
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The reason it follows early blight so, well, is because
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Because the fungus that causes it septoria like a person.
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Key is most active when temperatures range between 68
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and 77 degrees Fahrenheit. And the humidity is high and
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there has been some rainfall or some overhead irrigation wedding
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the plants that is usually the conditions that follow our hot
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humid weather where the early blight comes in.
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In fact, we're getting that now with overnight lows in that
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temperature range, but we're in a dry spell right now.
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So the humidity isn't quite as And but I have no doubt it's
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coming back soon and therefore septoria will probably rear its
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ugly head. Now Satori leaf spot damages the
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Tomato, foliage the petioles and the stems.
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But unlike early blight the fruit is not infected no
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infection usually occurs on the lower leaves near the ground.
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After the plants begin to set fruit, you'll get numerous small
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circular spots with dark borders.
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Surrounding a beige colored Center on once again.
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The older leaves. These are the ones that are
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usually closest to the ground. And then the center of those
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spots. You'll see these tiny black
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specks and those are the spore producing bodies.
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Severely spotted leaves will turn yellow.
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They'll die. They'll fall off the plant and
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then this defoliation is going to weaken the plant.
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It's going to reduce the size and the quality of the fruit and
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it's going to expose any fruit that does develop two sons
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called. Now, this fungus is not soil
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born but it can overwinter On crop residue from previous crops
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decaying vegetation. And on some of those weeds
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related to Tomato like that black Nightshade that we talked
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about. So prevention includes crop
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rotation as always and cleaning up.
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All the garden debris at the end of the season, keeping those
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related weeds in check and not using overhead irrigation.
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Now once you see the disease remove the infected leaves,
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prune them to ensure good airflow.
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And then that same copper spray that I'll be using Using for the
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early blight can also be used for Satori leaf spot.
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In my case, using it multiple times in the early part of the
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Season controls, both of them and I'm usually good to go after
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that. So the next is, he's on our list
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is bacterial spot. Now, this disease is caused by
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several species of the bacterium xanthomonas, which infect Green
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Tomatoes but not red tomatoes. So the disease is more prevalent
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during wet Seasons. Damage to the plants, includes
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leaf and fruit spots, which result in reduced yields
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defoliation. And so once again, Sun scalded
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fruit, the symptoms consists of numerous Angular 2 irregular
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water soap spots on the leaves and then slightly raised to
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scabby looking spots on the fruits that look like black
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dots. The leaf spots have a yellow
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Halo and the centers of the spots will start to dry out and
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they may cause the leaf to actually tear in the center.
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Now the bacteria survive the winter on volunteer tomato
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plants and on Infected plant debris, seeing a pattern here.
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Moist weather can also lead to disease development another
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pattern. Most outbreaks of the disease
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can be traced back to heavy. Rain, storms, that occurred in
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your area, infection of the leaves, occurs through natural
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openings, but infection of fruits must occur through insect
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punctures or other mechanical injuries.
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So, if you see the beginnings of this disease, you ought to make
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sure that you are clearing out as many of the insect pests as
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you can. And be careful not to puncture
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the fruit while you're working with it now.
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Bacterial spot is difficult to control once it appears in your
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garden. Any water movement from one leaf
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or plant to another like splashing, raindrops that
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overhead irrigation or touching and handling the plants while
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they're wet after it's been rained on that can spread the
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bacteria from the diseased. Plants to the healthy plants.
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So prevention is really important here.
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Only use disease, free seeds and plants crop rotation is key.
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And again, avoiding overhead. Ed, watering remove and dispose
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of all the disease in the plant material.
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If you see any and then prune your plants to promote air
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circulation. Once again, a copper fungicide
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will give fairly good control of this disease and get you all the
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way through to your Harvest. Now, the next disease on our
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list of dastardly tomato, diseases is anthracnose
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anthracnose on tomatoes is caused by a group of fungi
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within the genus Cola to track, mmm, and these species.
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These are primarily pathogens specifically of the tomato
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fruit. Now, as the fruit are ripening,
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the symptoms first become noticeable as small circular
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indented areas and then that indented area later gets this
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really dark Center to it. Those disease spots are going to
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continue to get bigger and bigger with time because the
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infection is continuing to spread deeper into the fruit
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then if you combine this with warm moist and humid weather,
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You'll see these pinkish colored spores that are standing up from
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the black fungal material, that's in the center of the
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spots and then those spores are spread by splashing water.
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Like you guessed, it rain or overhead irrigation.
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Now, the fungus that causes anthracnose can be transmitted
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within the seed. So if your seeds aren't
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certified as being free of this specific fungus, you can take
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matters into your own hands by treating them, by soaking them
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in. 82, °F water for 25 minutes, to destroy the fungus prior to
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planting. And there are some varieties of
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tomatoes that have built-in resistance to anthracnose.
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Once again, do not over head, irrigate your Tomatoes splashing
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water AIDS in the spread of those fungal spores, how many
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times are we going to say that in this episode plant?
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The garden in a sunny site and steak or cage?
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Your tomato plants to provide better air movement and better
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leaf. Drying conditions, you want your
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leaves dry, keep your garden weed free the presence of weeds,
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May raise humidity levels around the plants and that's going to
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slow the drying conditions. And of course you very well may
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have other weeds in the solanaceae family that are
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there. That can also Harbor this
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disease now because this disease does affect other plants.
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In the solanaceae family, you really want to be sure that
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you're rotating your crops. Preferably nothing in that
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family in the same space for 3 years, Like I said some weeds
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that infest the garden are also in the same family which is
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another reason to keep your garden as free of weeds as
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possible and I know easier said than done.
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The fungal spores can remain in the soil to inflict plants the
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following year. So mulching, your garden is
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going to help create a barrier between that soil surface and
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the fruit to reduce infections Harvest, your tomato, fruit
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daily, and then, remove and destroy the crop debris.
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As soon as the crop has finished bearing, do Do not add this
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debris to your compost. You want to burn it or
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otherwise, remove it from your property.
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Now, fungicide sprays can help reduce anthracnose disease
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specifically, the copper ones there are chemical based
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products that can be sprayed weekly to reduce infection.
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It's entirely up to you if you choose to use those just please
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follow the label directions. Remember the label is the law,
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for instance, there is a five-day waiting period between
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spraying Picking, if you're using a spray that contains
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mancozeb so be cognizant of what you're using and how you're
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using it. Our next disease is fusarium
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Wilt. This is a warm weather disease,
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caused by the fungus fusarium oxus Purim.
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Now, this is particularly common in the southern us, but it can
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occur anywhere, really the first indication of disease.
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Usually happens early in small plants where the lower leaves
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will droop and Wilt and then the Yves begin to turn yellow and
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then finally the entire plant just Wilt over and dies.
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Now, often leaves only on one side of the stem will turn
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yellow at first and the outside of the stem of these wilted
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plants won't show any signs of Decay, but when you cut it
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lengthwise, the lower stem will have a dark brown, discoloration
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of the xylem, which is that vascular system that
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distributes, the water throughout the plant.
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So the fungus is soil, born and Passes upward from The Roots
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into the vascular system of the stem.
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And it blocks the water conducting vessels in the plant
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and that causes the plant to wilt and die.
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There is no chemical control for fusarium Wilt.
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Once it's in your soil. It's there for the Long Haul.
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Once you see signs of this in your garden area, you'll need to
00:17:01
stop growing anything that is susceptible to the fungus.
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There are some cultivars that are resistant to through cerium
00:17:08
welt, if you must continue planting NG and crop rotation is
00:17:11
going to be absolutely important here, but you may end up needing
00:17:15
just to create raised beds, that contain no native soil.
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In order to prevent the pathogen from taking hold of your plants.
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Next up, Southern blight, this one is caused by the fungus
00:17:27
ethelia. Rolf CI, the first symptom just
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like other wilts is the drooping of the leaves.
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Now, on the stems, there will be a brown.
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Dry rot that develops? Right?
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Near the soil line. And then there's a white fungal
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growth with these brown little. I don't know.
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Bumps that look like mustard seeds.
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That will develop over top of that dry rot area.
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The stem lesion is going to develop really really rapidly
00:17:55
and it's going to grow the stem and result in a sudden and
00:17:59
permanent Wilt of all of the above ground parts of your
00:18:03
tomato plant, the fungus can also attack fruits where they
00:18:06
touch the soil. So it's important to stake your
00:18:08
plants this. Is can survive for years in the
00:18:12
soil and the plant debris. And it is favored most by
00:18:16
moisture conditions and high temperatures.
00:18:18
So crop rotation is essential to preventing Southern blight, do
00:18:23
not plant tomatoes after beans or Pepper or eggplants, it may
00:18:27
also help to plant small grains. After any of your solanaceae is
00:18:31
to help with the control and removal of plant debris,
00:18:34
immediately after harvest, will also help to control the disease
00:18:38
and Finally on our list of these tomato plagues is tomato.
00:18:44
Yellow Leaf curl. Now this is a virus that is
00:18:48
transmitted by whiteflies. We talked about this one a
00:18:50
little bit. A few episodes ago in our
00:18:52
question of the week this disease is extremely damaging to
00:18:57
fruit yield in your Tomatoes whiteflies bring the disease
00:19:01
into the garden from infected weeds nearby specifically, those
00:19:05
black night shades and Jimson weed after infection your tomato
00:19:09
plants. I have no symptoms for as long
00:19:12
as two to three weeks. And then suddenly, you'll begin
00:19:15
to see the upward curling of the leaves yellowing of the leaf
00:19:19
surface between the veins. We call this chlorosis, you'll
00:19:22
have smaller leaves than normal on the plant.
00:19:25
The plant will be stunted and then it'll start dropping its
00:19:28
flowers. If tomato plants are infected
00:19:30
early in their growth, there may be no fruit formed at all and
00:19:35
this infection Maybe random throughout the garden.
00:19:37
Some plants may get it and others may not.
00:19:40
Not removal of plants that have those initial symptoms may slow
00:19:45
the spread of the disease. And any infected plants that you
00:19:48
remove should immediately be bagged up to prevent the spread
00:19:52
of the whiteflies feeding on those plants and then bringing
00:19:55
them back into your garden to infect your uninfected plants.
00:19:59
Keep your weeds controlled in and around the garden site
00:20:02
because again those weeds maybe alternate hosts for the
00:20:05
whiteflies and also for the disease.
00:20:08
Now, if you see white flies appear, you can use a neem oil
00:20:12
spray to help keep them away or a horticultural oil spray.
00:20:15
If you had any infected plants at all or solid infestation of
00:20:19
whitefly at the end of the season, remove all susceptible
00:20:23
plants and burn them or dispose of them elsewhere.
00:20:27
You don't want the whitefly feeding on them or
00:20:29
overwintering. If this has been a problem in
00:20:31
your garden in the past, there are also tomato cultivars that
00:20:35
are resistant to Tomato Yellow Leaf curl.
00:20:38
Virus. Thanks for joining me on this
00:20:41
focal point Friday. I'll be back again on Tuesday
00:20:43
for another regular episode of the just grow something podcast.
00:20:46
So, until next time my gardening friends, keep on cultivating
00:20:49
that dream garden and we'll talk again soon.
00:20:38
Virus. Thanks for joining me on this
00:20:41
focal point Friday. I'll be back again on Tuesday
00:20:43
for another regular episode of the just grow something podcast.
00:20:46
So, until next time my gardening friends, keep on cultivating
00:20:49
that dream garden and we'll talk again soon.