Leaf Spot

Talon1189 · September 22, 2011

I have both a Big Beef and a Mortgage lifter plants that are getting "leaf spot" I have sprayed with Daconil every 7-10 days during the season. I stopped 4 weeks ago. I pray that I do not have a hard frost over the next 3 weeks here in Michigan. Should I be worried about "Leaf Spot" here at this late level in this season? Just let it go this late? I will be lucky to have 3-4 weeks left on my tomato season here.......Very disappointing season here for sure

RayR · September 23, 2011

I guess if the decent weather holds up, I would be concerned. Septoria leaf spot can spread pretty rapidly once it takes hold and the conditions are optimal. I haven't had any leaf spot to speak of all summer, but now that the weather is wetter and cooler, it has made itself known.
I haven't sprayed any preventative chemical fungicide at all this year. I have some left over copper from last year on the shelf, but haven't used a drop. I have been spraying with Seacom PGR and a biological fungicide I'm experimenting with every week to week and a half, but I stopped a couple weeks ago and now Septoria is here on some plants! Oh well, the temps is looking OK for the next week anyway so it's back to spraying my concoction and see if it has any positive effect on a spreading Septoria infection.

**carolyn137** · September 23, 2011

Talon, since you put "leaf spot" in parens I'm wondering if you're referring to Septoria Leaf Spot or just leaf spot in general b'c it could make a difference in how you proceed as well as the plants in terms of what the actual foliage disease might be.

Talon1189 · September 23, 2011

Quote:

Originally Posted by carolyn137

Talon, since you put "leaf spot" in parens I'm wondering if you're referring to Septoria Leaf Spot or just leaf spot in general b'c it could make a difference in how you proceed as well as the plants in terms of what the actual foliage disease might be.

It is Septoria leaf spot

fortyonenorth · September 23, 2011

I wouldn't worry about it this late in the season. Frankly, you're fortunate you still have fruit on the vine. With the cooler, dryer conditions, I think frost will fell your plants before Septoria.

Talon1189 · September 23, 2011

Quote:

Originally Posted by fortyonenorth

I wouldn't worry about it this late in the season. Frankly, you're fortunate you still have fruit on the vine. With the cooler, dryer conditions, I think frost will fell your plants before Septoria.

That is the answer that I was wondering about.......Thanks fortyonenorth

**carolyn137** · September 23, 2011

Quote:

Originally Posted by Talon1189

It is Septoria leaf spot

OK, now that I know that it is Septoria I agree that it's too late in the season to spray.

Many commercial farmers do continue to spray with Daconil late in the season, not so much for Septora or Early Blight, but to help prevent anthracnose from infecting the surface of the fruits as it often does when nights get cooler towards Fall.

Talon1189 · September 23, 2011

Quote:

Originally Posted by carolyn137

OK, now that I know that it is Septoria I agree that it's too late in the season to spray.

Many commercial farmers do continue to spray with Daconil late in the season, not so much for Septora or Early Blight, but to help prevent anthracnose from infecting the surface of the fruits as it often does when nights get cooler towards Fall.

Last year I was a newbie and got Septoria about the same time. I was clueless back then. It was much worse on my Better Boy plants last season. I hang around gardening sites much more than I should be here.....

I am much smarter for it thanks in a big part to your post and advice Carolyn

Thank you for all your knowledge and time that you spend educating others.....I do appreciate it

>>>>>>Talon

b54red · September 24, 2011

My conditions are a lot different down here so I am still spraying because Septoria has gotten much worse since mid summer. We have had a few sprinkles but no real rain lately but that seems to be enough to make diseases spread faster. I think the fall whiteflies may also be responsible for spreading Septoria; but they are impossible to eradicate so I have to keep spraying because we could still have a couple of months of decent growing weather.

lakelady · October 4, 2011

Quote:

Originally Posted by carolyn137

Talon, since you put "leaf spot" in parens I'm wondering if you're referring to Septoria Leaf Spot or just leaf spot in general b'c it could make a difference in how you proceed as well as the plants in terms of what the actual foliage disease might be.

Carolyn, could you explain how treating them is different? It took me a long time to figure out I had septoria on my plants this year as my garden center was really no help at all and just told me it was fungus and gave me a copper spray. It helped a bit to hold it at bay but once it took hold, I really never got the upper hand again this season. Although, even as I've given up watering what is left, and as dead as the plants look they are still ripening tomatoes (thus far).

**carolyn137** · October 4, 2011

Quote:

Originally Posted by lakelady

Carolyn, could you explain how treating them is different? It took me a long time to figure out I had septoria on my plants this year as my garden center was really no help at all and just told me it was fungus and gave me a copper spray. It helped a bit to hold it at bay but once it took hold, I really never got the upper hand again this season. Although, even as I've given up watering what is left, and as dead as the plants look they are still ripening tomatoes (thus far).

THe only point I was making is if the foliage diseases were either Early Blight ( A. solani) or Septoria Leaf Spot, that prevention would be a spray schedule with a good known anti-fungal.

But of the "spots" on the foliage were due to either of the common bacterial pathogens, Bacterial Speck or Bacterial Spot, that since they are bactrial one wouldn't treat with an anti-fungal.

Copper is not the best of the known effective anti-fungals IMO. Daconil ( chlorothalonil ) is and it's very low re toxicity and can be applied up to the day of harvest.

But there are I can't tell you how many threads here already at Tville that discuss how to prevent foliage infections. Some refuse to use anything that's synthetic, some don't mind. I don't care if a product is synthetic or natural b'c my concern is with overall toxicity to humans, pets, bees and the environment in general. And some natural products, such as Rotenone, are more harmful to the environment than many synthetic products. And there's concern creeping in about build up of copper products in soils as well.

lakelady · October 4, 2011

Thanks, I've been reading a lot here about Daconil lately. I try to be organic, but safety is very important to me. As someone who dabbles in natural health care and products, I only know too well how dangerous some "natural" products can be.

There is so much to learn about growing tomatoes that I never knew I didn't know...

September 22, 2011	#1
Talon1189 Tomatovillian™ Join Date: Apr 2010 Location: Farmington, Michigan. Zone 5b/6a Posts: 421	Leaf Spot I have both a Big Beef and a Mortgage lifter plants that are getting "leaf spot" I have sprayed with Daconil every 7-10 days during the season. I stopped 4 weeks ago. I pray that I do not have a hard frost over the next 3 weeks here in Michigan. Should I be worried about "Leaf Spot" here at this late level in this season? Just let it go this late? I will be lucky to have 3-4 weeks left on my tomato season here.......Very disappointing season here for sure __________________ Always looking for a better way to grow tomatoes ..........

September 23, 2011	#3
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	Talon, since you put "leaf spot" in parens I'm wondering if you're referring to Septoria Leaf Spot or just leaf spot in general b'c it could make a difference in how you proceed as well as the plants in terms of what the actual foliage disease might be. __________________ Carolyn

September 23, 2011	#2
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,466	I guess if the decent weather holds up, I would be concerned. Septoria leaf spot can spread pretty rapidly once it takes hold and the conditions are optimal. I haven't had any leaf spot to speak of all summer, but now that the weather is wetter and cooler, it has made itself known. I haven't sprayed any preventative chemical fungicide at all this year. I have some left over copper from last year on the shelf, but haven't used a drop. I have been spraying with Seacom PGR and a biological fungicide I'm experimenting with every week to week and a half, but I stopped a couple weeks ago and now Septoria is here on some plants! Oh well, the temps is looking OK for the next week anyway so it's back to spraying my concoction and see if it has any positive effect on a spreading Septoria infection.

September 23, 2011	#5
fortyonenorth Tomatovillian™ Join Date: Jan 2010 Location: NW Indiana Posts: 1,150	I wouldn't worry about it this late in the season. Frankly, you're fortunate you still have fruit on the vine. With the cooler, dryer conditions, I think frost will fell your plants before Septoria.

September 24, 2011	#9
b54red Tomatovillian™ Join Date: Sep 2009 Location: Alabama Posts: 7,068	My conditions are a lot different down here so I am still spraying because Septoria has gotten much worse since mid summer. We have had a few sprinkles but no real rain lately but that seems to be enough to make diseases spread faster. I think the fall whiteflies may also be responsible for spreading Septoria; but they are impossible to eradicate so I have to keep spraying because we could still have a couple of months of decent growing weather.

October 4, 2011	#12
lakelady Tomatovillian™ Join Date: Aug 2011 Location: northern NJ zone 6b Posts: 1,862	Thanks, I've been reading a lot here about Daconil lately. I try to be organic, but safety is very important to me. As someone who dabbles in natural health care and products, I only know too well how dangerous some "natural" products can be. There is so much to learn about growing tomatoes that I never knew I didn't know...