This is early blight, right?

pooklette · July 20, 2009

For the last two years, some disease has been killing off all my plants before I can get any kind of harvest. It usually starts with spotting and yellowing of the lower leaves and stems. No matter what I do, it quickly moves its way up the plant and kills the whole thing. This photo from the University of Maryland shows exactly what my plants look like by the time August rolls around, except that the fruits also get black spots and rot on the plant before they even begin to ripen.

I thought I was finally in the clear this year because I haven't seen any spots yet. They usually show up within two weeks of transplant.

Here are some photos I took in my garden today (apologies for the quality...very old camera.) This is early blight, isn't it?

I'd say about 50% of the leaves on this plant have the black splotches in addition to the ones you see on the stem. These spots were not visible last weekend, although we've had an entire week of cool, damp weather.

I avoid watering from above. I have tried mulching around my plants, using copper dust and removing spotty leaves/branches to prevent it from spreading. Despite these efforts, my plants all die, their fruit liquified by August 1st.

So far, I only see the evil polka-dots on two plants. I'm hoping someone can tell me what disease I have here and give me some pointers on preventing each and every one of my plants from dying again this year.

jcmorse33 · July 20, 2009

Early Blight never affects the fruit on my plants, nor does it look like the spots you've taken pictures of. The spots look more like Septoria leaf spot to me... That said, Septoria doesn't affect the fruit on my plants that have it either. So I would guess you are more likely to be dealing with Bacterial Speck or Bacterial Spot which look very similar at least in the pictures I've seen on various cooperative extension web pages.

I don't know what you would use to treat Speck or Spot. Perhaps a copper spray. If you have had plants turned to mush by this disease before I would say you probably need to avoid planting in that location for a few years as the soil is likely infested with spores which will remain present for quite some time. Even if you plant in containers spores in the soil can still splash up onto the leaves during a hard rain. I tried planting in a bed that had bad Septoria leaf spot last year and all my plants got it again quite badly despite my use of plastic mulch and regular spraying.

--Justin

pooklette · July 20, 2009

Thanks so much for the quick response. I did rotate my plants, in the hopes of avoiding another bad year but maybe I haven't moved them far enough? They were moved from one end of the garden to the other...about 25 feet. Corn and beans were in this spot last year.

jcmorse33 · July 21, 2009

The 25 foot move is probably why it took this long for your plants to get it.

If your plants are significantly larger than they normally are when they get the spots I'd say there's a decent chance they can just outgrow it provided you can get an effective spray to prevent it from spreading further and the weather cooperates (wet weather tends to negate my spraying efforts). Pruning off affected leaves and fruit should also help as it will reduce the source of new spores.

rsg2001 · July 22, 2009

Interesting. I have two plants of one variety - yellow currant - that look just like Pooklette's. None of the others have it. (One of these is in the ground and the other in a container, not near each other.) I gather that variety must be more susceptible.

aninocentangel · July 22, 2009

It does look a lot like early blight to me, unfortunately the fungal diseases often resemble each other closely. The master gardener at the nursery suggested that we consider treating the lawn for fungii next year, to help control what the vegetables are exposed to. And to get rid of the mulching blade as she feels thatch helps propagate diseases.

**carolyn137** · July 22, 2009

Pooklette, where are you in zone 5 for it really makes a difference this year in terms of diagnosis,

If it's Early Blight ( A. solani) you should see concentric rings within the leaf spots but there's not enough definition for me to see if that's there. Besides, fruits affected by EB have no spots, just infection in a circle around the stem.

The spots are too regular to be Septoria Leaf Spot as I see it.

So I think it's more likely Bacterial Speck or Spot and in terms of treatment both would be treated the same.

All four of the common foliage disease pathogens are transmitted by wind, rain and dust, they aren't naturally soil dwelling as are the systemic diseases Verticillium, Fusarium, etc.

So rotation would only be necessary if bacteria from previous years had been shed to the soil from infected plants and then there was splashback infection.

Someone mentioned treating the lawn for fungi but the tomato pathogens wouldn't be found there, nor would the bacterial foliage pathogens.

I have some Bacterial Speck on my plants this year and I've had Freda, who does all my gardening for me, take off every affected leaf as soon as one appears.

I'm also having her spray with Bonide Copper for the Bacterial Speck/Spot and alternating that with Daconil b'c I'm in the NE where Late Blight ( P.infestans) is a major problem this year.

And the fruits of both Bacterial Speck and Spot can have small black spots on the fruits.

So do check out some pictures of both Bacterial Speck and Bacterial Spot and see if you can make a match.

It poured rain here for 7 hours yesterday and that's one major way in which the tomato foliage pathogens get spread. In the last month or so there have been only two days in a row without rain and at this point I'm afraid that I'm not going to be able to mature fruits; just too cold and rainy.

Hope that helps.

bcday · July 22, 2009

I've had Bacterial Speck here and it doesn't cause the fruit to rot before it begins to ripen. The damage to fruit is mostly cosmetic with superficial raised black dots that don't go very far into the interior of the fruit. When the fruit begins to ripen, the area around the specks stays green. I think Bacterial Spot lesions also don't go much below the fruit skin and seldom cause the fruit to rot before it ripens.

If Pooklette's fruit is rotting while it's still green, I think something else must be infecting her plants. A good clear pic of the spots on the fruit would be helpful.

pooklette · July 22, 2009

Thanks for all the comments so far.

Quote:

Originally Posted by Carolyn

Pooklette, where are you in zone 5 for it really makes a difference this year in terms of diagnosis,

I am in southern WI. Usually the leaf spots show up within two weeks of transplant (late May or early June.) This year they held off until mid-July.

Quote:

If it's Early Blight ( A. solani) you should see concentric rings within the leaf spots but there's not enough definition for me to see if that's there. Besides, fruits affected by EB have no spots, just infection in a circle around the stem.

I've never noticed concentric rings. Generally, the leaves have black spots that vary between 1/8" to 1/4" in diameter. Most are round, some are irregular in shape. The black splotches on the stems are similar.

ETA: The leaf spots do not dry up and 'fall out' leaving holey leaves. The spots multiply until the leaf and its entire branch turn yellow and dry up. This usually happens from the bottom of the plant, on up.

I'm starting to think I have been seeing the effects of more than one disease. I have no fruits on the spotty plants yet this year. During the last two 'diseased seasons', here's what I saw:

Some of the green fruits had tiny dark specks like I see in the Bacterial Speck photo here:

http://aggie-horticulture.tamu.edu/p.../bac_spec.html

The black spots that turn my fruits to mush before they've even fully ripened look a lot like the Anthracnose example here:

http://aggie-horticulture.tamu.edu/p...e/anthrac.html

The fruits end up with a bunch of black pencil-eraser size spots that turn soft and start cracking/oozing right around the time they start to blush. By the time the fruits are almost ripe, they're reduced to tomato goo.

ETA: By almost ripe, I'm referring to pink, black, or orange tomatoes that are still green on the stem end. They're definately not tomatoes turned to goo because they're overripe.

Over the last two years I've tried removing the spotty leaves and branches. It still spread like wildfire. I tried dusting the plants with copper powder. Didn't seem to make a difference. I tried mulching around the plants, thinking it would help to prevent the dirt from splashing up on the plants, and it did, but the black spots still showed up.

A few days ago, I broke down and bought Daconil but it's been raining ever since. I have to wait until the rain stops to use it, right? (This year, the spots showed up after the hot dry weather turned perpetually cool and humid. Perhaps that's a clue?)

dice · July 23, 2009

It could be that the stuff is blowing in on the wind from some
weed, tree, or other local plant that gets infected, rather than
splashing up through the mulch around your tomato plants.
A tour of the whole yard looking for it might answer that
question for you.

July 20, 2009	#1
pooklette Tomatovillian™ Join Date: Feb 2006 Location: Zone 5 Posts: 262	This is early blight, right? For the last two years, some disease has been killing off all my plants before I can get any kind of harvest. It usually starts with spotting and yellowing of the lower leaves and stems. No matter what I do, it quickly moves its way up the plant and kills the whole thing. This photo from the University of Maryland shows exactly what my plants look like by the time August rolls around, except that the fruits also get black spots and rot on the plant before they even begin to ripen. I thought I was finally in the clear this year because I haven't seen any spots yet. They usually show up within two weeks of transplant. Here are some photos I took in my garden today (apologies for the quality...very old camera.) This is early blight, isn't it? I'd say about 50% of the leaves on this plant have the black splotches in addition to the ones you see on the stem. These spots were not visible last weekend, although we've had an entire week of cool, damp weather. I avoid watering from above. I have tried mulching around my plants, using copper dust and removing spotty leaves/branches to prevent it from spreading. Despite these efforts, my plants all die, their fruit liquified by August 1st. So far, I only see the evil polka-dots on two plants. I'm hoping someone can tell me what disease I have here and give me some pointers on preventing each and every one of my plants from dying again this year. Last edited by pooklette; July 21, 2009 at 11:07 PM.

July 22, 2009	#7
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	Pooklette, where are you in zone 5 for it really makes a difference this year in terms of diagnosis, If it's Early Blight ( A. solani) you should see concentric rings within the leaf spots but there's not enough definition for me to see if that's there. Besides, fruits affected by EB have no spots, just infection in a circle around the stem. The spots are too regular to be Septoria Leaf Spot as I see it. So I think it's more likely Bacterial Speck or Spot and in terms of treatment both would be treated the same. All four of the common foliage disease pathogens are transmitted by wind, rain and dust, they aren't naturally soil dwelling as are the systemic diseases Verticillium, Fusarium, etc. So rotation would only be necessary if bacteria from previous years had been shed to the soil from infected plants and then there was splashback infection. Someone mentioned treating the lawn for fungi but the tomato pathogens wouldn't be found there, nor would the bacterial foliage pathogens. I have some Bacterial Speck on my plants this year and I've had Freda, who does all my gardening for me, take off every affected leaf as soon as one appears. I'm also having her spray with Bonide Copper for the Bacterial Speck/Spot and alternating that with Daconil b'c I'm in the NE where Late Blight ( P.infestans) is a major problem this year. And the fruits of both Bacterial Speck and Spot can have small black spots on the fruits. So do check out some pictures of both Bacterial Speck and Bacterial Spot and see if you can make a match. It poured rain here for 7 hours yesterday and that's one major way in which the tomato foliage pathogens get spread. In the last month or so there have been only two days in a row without rain and at this point I'm afraid that I'm not going to be able to mature fruits; just too cold and rainy. Hope that helps. __________________ Carolyn

July 23, 2009	#10
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	It could be that the stuff is blowing in on the wind from some weed, tree, or other local plant that gets infected, rather than splashing up through the mulch around your tomato plants. A tour of the whole yard looking for it might answer that question for you. __________________ -- alias

July 20, 2009	#2
jcmorse33 Tomatovillian™ Join Date: Jun 2007 Location: Central Virginia Posts: 242	Early Blight never affects the fruit on my plants, nor does it look like the spots you've taken pictures of. The spots look more like Septoria leaf spot to me... That said, Septoria doesn't affect the fruit on my plants that have it either. So I would guess you are more likely to be dealing with Bacterial Speck or Bacterial Spot which look very similar at least in the pictures I've seen on various cooperative extension web pages. I don't know what you would use to treat Speck or Spot. Perhaps a copper spray. If you have had plants turned to mush by this disease before I would say you probably need to avoid planting in that location for a few years as the soil is likely infested with spores which will remain present for quite some time. Even if you plant in containers spores in the soil can still splash up onto the leaves during a hard rain. I tried planting in a bed that had bad Septoria leaf spot last year and all my plants got it again quite badly despite my use of plastic mulch and regular spraying. --Justin

July 21, 2009	#4
jcmorse33 Tomatovillian™ Join Date: Jun 2007 Location: Central Virginia Posts: 242	The 25 foot move is probably why it took this long for your plants to get it. If your plants are significantly larger than they normally are when they get the spots I'd say there's a decent chance they can just outgrow it provided you can get an effective spray to prevent it from spreading further and the weather cooperates (wet weather tends to negate my spraying efforts). Pruning off affected leaves and fruit should also help as it will reduce the source of new spores.

July 22, 2009	#5
rsg2001 Tomatovillian™ Join Date: Jun 2006 Location: New York Zone 6 Posts: 479	Interesting. I have two plants of one variety - yellow currant - that look just like Pooklette's. None of the others have it. (One of these is in the ground and the other in a container, not near each other.) I gather that variety must be more susceptible.

July 22, 2009	#6
aninocentangel Tomatovillian™ Join Date: Mar 2008 Location: 8a Coastal SC Posts: 251	It does look a lot like early blight to me, unfortunately the fungal diseases often resemble each other closely. The master gardener at the nursery suggested that we consider treating the lawn for fungii next year, to help control what the vegetables are exposed to. And to get rid of the mulching blade as she feels thatch helps propagate diseases.

July 22, 2009	#8
bcday Tomatovillian™ Join Date: Jan 2006 Location: NY z5 Posts: 1,205	I've had Bacterial Speck here and it doesn't cause the fruit to rot before it begins to ripen. The damage to fruit is mostly cosmetic with superficial raised black dots that don't go very far into the interior of the fruit. When the fruit begins to ripen, the area around the specks stays green. I think Bacterial Spot lesions also don't go much below the fruit skin and seldom cause the fruit to rot before it ripens. If Pooklette's fruit is rotting while it's still green, I think something else must be infecting her plants. A good clear pic of the spots on the fruit would be helpful.