Diagnosis: Yellow spots with dark specks?

sjamesNorway · June 18, 2015

This started with yellow spots, which are showing on Spudakee, Earl's Faux, Green Giant, and Brandy Boy in my greenhouse. Now some have dark specks in the middle. There are also dark specks on the backside of the leaves. Can someone help with a diagnosis, and hopefully a remedy?

Steve

RayR · June 18, 2015

Most likely the early stages of a fungal infection. As to which pathogen who knows, many can have the same appearance early on. What are common pathogens in greenhouses in Norway? What fungicidal remedies are available in Norway?

sjamesNorway · June 18, 2015

Quote:

Originally Posted by RayR

Most likely the early stages of a fungal infection. As to which pathogen who knows, many can have the same appearance early on. What are common pathogens in greenhouses in Norway? What fungicidal remedies are available in Norway?

I'm not sure what pathogens are common here. I have a small private greenhouse, and this is my first year with it. I imagine they're the same as in the states. There are NO fungicides available to hobby gardeners in Norway.

feldon30 · June 18, 2015

Quote:

Originally Posted by sjamesNorway

There are NO fungicides available to hobby gardeners in Norway.

I looked and could not find chlorothalonil available for sale anywhere in Norway. It's outright banned in Sweden.

The photos you posted are at such an extremely early stage, it's hard to know what the issue is. I don't start worrying until entire leaves are yellowed with brown rings.

Mike723 · June 18, 2015

Agree with Ray.. Possibly early stages of septoria or another foliar disease.. I'd get my hands on (at the very least) a copper based spray.. In the mean time, take care in removing all the leaves displaying those symptoms.. Be careful not to touch any healthy leaves in the process, and wash your hands well before returning to the garden..

Kikaida · June 18, 2015

Some around here state they use diluted bleach for certain fungal infections, seems like a home brewed concoction is your best bet.

Bipetual · June 18, 2015

Make sure you have plenty of air circulation to keep the air moving between the leaves. Unless it's a lot of leaves, you might want to remove the spotted ones and get rid of them, don't compost them.

PhilaGardener · June 18, 2015

Adding to what others have suggested - also try to keep the leaves try when watering.

beeman · June 18, 2015

You could try a milk spray. Use any milk at 10-1 ratio, spray both sides of the affected leaves, ans spray around to run off.
Cured some fungal stuff on the cucumbers in my greenhouse.
http://www.tomatoville.com/showthrea...ght=Milk+spray

sjamesNorway · June 19, 2015

Thank you all for your replies. I'm going to try hydrogen peroxide. I received information from an ongoing thread here: "Diluted bleach as spray". (I would probably have tried bleach, but the bleach here has a small amount of caustic soda, sodium hydroxide, added.)

Steve

zipcode · June 20, 2015

A picture from a bit farther away would be good. Are only the lower leaves affected, preferably the ones towards the light?
Because it looks a lot like plain old magnesium deficiency.
Here is a typical case on one of my leaves:
SAM_6999.jpg

sjamesNorway · June 20, 2015

Hi zipcode. That's exactly what they look like(!), which is a little strange because I added a tablespoon of epsom salts to the planting hole. And yes, they are the lower leaves getting the most light. I guess they need more epsom salt. Many thanks for the advice.

Steve

HydroExplorer · June 20, 2015

Quote:

Originally Posted by sjamesNorway

Hi zipcode. That's exactly what they look like(!), which is a little strange because I added a tablespoon of epsom salts to the planting hole. And yes, they are the lower leaves getting the most light. I guess they need more. Many thanks for the advice.

Steve

If it is Mg deficiency that can happen if you overdose on Potassium. OD on Potassium locks out Mg causing Mg deficiency.

Fungus and some nutrient deficiencies and some poisons look very similar. If only the plants would tell us for sure.

sjamesNorway · June 21, 2015

Quote:

Originally Posted by HydroExplorer

If it is Mg deficiency that can happen if you overdose on Potassium. OD on Potassium locks out Mg causing Mg deficiency.

Fungus and some nutrient deficiencies and some poisons look very similar. If only the plants would tell us for sure.

My container mix scored "high" on potassium on a home soil test. (There were lots of banana peels in the compost added to the mix.) So there probably is an overdose of potassium. Is there anything I can do about this? Will adding epsom salts help?

zipcode · June 21, 2015

It will help some, best is some foliar, this way you bypass the roots. Look online for how much MgSO4 concentration to use for foliar.
The affected leaves will not recover, but should slow down the rate with which it appears on other leaves.
I have it every year in containers, it's kind of unavoidable it seems, I just gradually cut older leaves which are too affected.

June 18, 2015	#5
Mike723 Tomatovillian™ Join Date: Sep 2014 Location: CT Posts: 290	Agree with Ray.. Possibly early stages of septoria or another foliar disease.. I'd get my hands on (at the very least) a copper based spray.. In the mean time, take care in removing all the leaves displaying those symptoms.. Be careful not to touch any healthy leaves in the process, and wash your hands well before returning to the garden.. Last edited by Mike723; June 18, 2015 at 08:39 PM.

June 20, 2015	#12
sjamesNorway Tomatovillian™ Join Date: Oct 2014 Location: Norway Posts: 1,049	Hi zipcode. That's exactly what they look like(!), which is a little strange because I added a tablespoon of epsom salts to the planting hole. And yes, they are the lower leaves getting the most light. I guess they need more epsom salt. Many thanks for the advice. Steve Last edited by sjamesNorway; June 21, 2015 at 08:17 AM.

June 18, 2015	#2
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,466	Most likely the early stages of a fungal infection. As to which pathogen who knows, many can have the same appearance early on. What are common pathogens in greenhouses in Norway? What fungicidal remedies are available in Norway?

June 18, 2015	#6
Kikaida Tomatovillian™ Join Date: Apr 2015 Location: Valencia, CA Posts: 258	Some around here state they use diluted bleach for certain fungal infections, seems like a home brewed concoction is your best bet.

June 18, 2015	#7
Bipetual Tomatovillian™ Join Date: Apr 2015 Location: Illinois, zone 5a Posts: 579	Make sure you have plenty of air circulation to keep the air moving between the leaves. Unless it's a lot of leaves, you might want to remove the spotted ones and get rid of them, don't compost them.

June 18, 2015	#8
PhilaGardener Tomatovillian™ Join Date: Jan 2014 Location: Near Philadelphia, PA Posts: 1,940	Adding to what others have suggested - also try to keep the leaves try when watering.

June 18, 2015	#9
beeman Tomatovillian™ Join Date: Jul 2009 Location: Ontario, Canada Posts: 692	You could try a milk spray. Use any milk at 10-1 ratio, spray both sides of the affected leaves, ans spray around to run off. Cured some fungal stuff on the cucumbers in my greenhouse. http://www.tomatoville.com/showthrea...ght=Milk+spray

June 19, 2015	#10
sjamesNorway Tomatovillian™ Join Date: Oct 2014 Location: Norway Posts: 1,049	Thank you all for your replies. I'm going to try hydrogen peroxide. I received information from an ongoing thread here: "Diluted bleach as spray". (I would probably have tried bleach, but the bleach here has a small amount of caustic soda, sodium hydroxide, added.) Steve

June 20, 2015	#11
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	A picture from a bit farther away would be good. Are only the lower leaves affected, preferably the ones towards the light? Because it looks a lot like plain old magnesium deficiency. Here is a typical case on one of my leaves: SAM_6999.jpg

June 21, 2015	#15
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	It will help some, best is some foliar, this way you bypass the roots. Look online for how much MgSO4 concentration to use for foliar. The affected leaves will not recover, but should slow down the rate with which it appears on other leaves. I have it every year in containers, it's kind of unavoidable it seems, I just gradually cut older leaves which are too affected.