Help! Do i have blight?

Black River · May 29, 2011

We have had over 26 in. of rain here in the past month, and a couple of days ago i noticed these spots on my potato leaves:

It looks like pictures i've seen of blight, but i read that blight will start on the lower leaves, this is on the upper leaves too. Our plants are fairly mature and have already bloomed. I pulled up a few potatoes and they looked ok, and they were about golf ball size. At first we tried to pick off the affected leaves, but it's still spreading, and i have over 80 tomato plants in the ground. I did a forum search but i'm pretty much a newbie and i am still unsure. How can i protect the tomatoes? What is this and what should i do?

**Tom Wagner** · May 29, 2011

http://www.plantpath.wisc.edu/wivegd...s/potatoeb.gif

Looking at the above link and your photo...I would say you are right about it being early blight.

With your tomatoes the early blight may also spread...lower leaves first as with the potatoes. Sometimes if the weather dries out the early blight does not spread as much.

I am the wrong person to ask about control....I don't use chemicals and I don't even use organic sprays.

I like to see natural resistance to early blight and late blight and that is why I am focusing on lines like my Skykomish and Healthy Colors, Bouncing Betties, etc. with tomatoes.

I also have good res. to early blight in potatoes especially those that are dual LB/EB res.

One reason I don't worry about the early blight is that I have so many plots that if one plot is bad ...maybe another plot is untouched. But then again I make note of any variety that tolerates the fungals better than others.

Most of the time tomatoes and potatoes will tolerate a certain amount of early blight without too much yield damage. Unsightly...yes.

tam91 · May 29, 2011

Many people spray with Daconil (chlorothalonil). I am one of them.

wmontanez · May 29, 2011

I read removing the affected folliage and spray Serenade or 1.5%Hydrogen peroxide is used for early blight as an organic method. Never had to use it so far...

Black River · June 1, 2011

Thank you for the replies. It seems like some of my plants have recovered a little since drier weather has set in. I'm watching the tomatoes closely but so far no spots on them.

May 29, 2011	#1
Black River Tomatovillian™ Join Date: Mar 2011 Location: NE Arkansas Posts: 16	Help! Do i have blight? We have had over 26 in. of rain here in the past month, and a couple of days ago i noticed these spots on my potato leaves: It looks like pictures i've seen of blight, but i read that blight will start on the lower leaves, this is on the upper leaves too. Our plants are fairly mature and have already bloomed. I pulled up a few potatoes and they looked ok, and they were about golf ball size. At first we tried to pick off the affected leaves, but it's still spreading, and i have over 80 tomato plants in the ground. I did a forum search but i'm pretty much a newbie and i am still unsure. How can i protect the tomatoes? What is this and what should i do?

May 29, 2011	#3
tam91 Tomatovillian™ Join Date: Aug 2010 Location: Crystal Lake IL Posts: 2,484	Many people spray with Daconil (chlorothalonil). I am one of them. __________________ Tracy

May 29, 2011	#4
wmontanez Tomatovillian™ Join Date: Jan 2010 Location: MA Posts: 776	I read removing the affected folliage and spray Serenade or 1.5%Hydrogen peroxide is used for early blight as an organic method. Never had to use it so far... __________________ Wendy

May 29, 2011	#2
Tom Wagner Crosstalk™ Forum Moderator Join Date: Aug 2006 Location: 8407 18th Ave West 7-203 Everett, Washington 98204 Posts: 1,157	http://www.plantpath.wisc.edu/wivegd...s/potatoeb.gif Looking at the above link and your photo...I would say you are right about it being early blight. With your tomatoes the early blight may also spread...lower leaves first as with the potatoes. Sometimes if the weather dries out the early blight does not spread as much. I am the wrong person to ask about control....I don't use chemicals and I don't even use organic sprays. I like to see natural resistance to early blight and late blight and that is why I am focusing on lines like my Skykomish and Healthy Colors, Bouncing Betties, etc. with tomatoes. I also have good res. to early blight in potatoes especially those that are dual LB/EB res. One reason I don't worry about the early blight is that I have so many plots that if one plot is bad ...maybe another plot is untouched. But then again I make note of any variety that tolerates the fungals better than others. Most of the time tomatoes and potatoes will tolerate a certain amount of early blight without too much yield damage. Unsightly...yes.

June 1, 2011	#5
Black River Tomatovillian™ Join Date: Mar 2011 Location: NE Arkansas Posts: 16	Thank you for the replies. It seems like some of my plants have recovered a little since drier weather has set in. I'm watching the tomatoes closely but so far no spots on them.