Tomato blight like fungus - is it blight

[Mark_Riga]

Hello, hopefully I've attached 3 files showing the problem. Although very like blight, it didnn't seem to harm the fruit and was quite slow to kill off the plants, the close ups are of one that is still 'alive'.

The first attack of actual blight I noticed in the greenhouse was mid June when I saw a few affected leaves that I picked immediately. A few weeks later, probably in July, this appeared like a rash on too many plant/leaves to pick.
The same happened last year but I had been watering with a hosepipe and put it down to being lazy but this year I've used drip irrigation and watering cans. I have used bordeaux spray this year, last year I didn't but not sure it has had a noticable affect.
About the same time, some potatoes outside were affected by blight and gradually died off, apart from the Sarpo Mira that I dug up last week. The blight on the potatoes progressed reasonably rapidly but as you can see, some of the tomatoes are still alive and not of the fruit are affected (some have greenback but that is OK with me.
Any thoughts on it or how long it is likely to persist in the greenhouse would be welcome.
Mark

[Bigmallly]

As I am not sure if it is blight or not, I would play safe & pick any ripe or part ripe Toms.........Looks more like some kind of mineral deficiency.

[Potstubsdustbins]

I am with BM on this one, blight does not usually progress slowly.

Pic 1 could be magnesium deficiency or even an old leaf that's dying back.

Pic 2. I have leaves like this on my toms at this time in the season, never seems to do any harm.

[bramble]

As Bigmally said. I would pick whatever fruit is starting to turn red and they will ripen for you. I would cut back every and all plants/leaves thst are discoloured or diseased and see what you are then left with. If it gets any worse I would cut your losses snd take the whole lot out and start again next season.
Good luck whatever you decide.

[Mark_Riga]

I think mineral deficiency is unlikely but not sure - in the second pic along, the underside of a leaf, all the grey areas seem to be a mold/fungus that can be washed off to some extent and corresponds with the yellow patches on the top of the leaves (these start off as pale green). Similar to blight only not dieing off very quickly so I did get a reasonable crop - only they should be cropping for a long while yet but won't be.

[Bigmallly]

Whatever the problem is, it's not going to improve so really all the damaged/diseased leaves need to be removed as they are not helping the plant anyway.

[Jungle Jane]

In the third photo the plant under the greenhouse window looks like it's got a fungal issue at the moment,you can remove all the lower leaves below the tomatoes to improve airflow & to stop water splashing up on the leaves,try to keep the leaves dry all the time. It could've been caused by wet leaves & humidity. Is there enough space between each plant? I had something similar years ago but outside in grow bags,my plants were too close together & the plants in the crush of things in the middle suffered most,the same brown areas like the photo. Do you think your plants might have had magnesium deficiency back in June? It starts off like green patches between the leaf veins,then the patches gradually darken to brown. If they did Epsom salts will sort out the problem if caught early enough

[Mark_Riga]

Magnesium deficiency is possible, but quite a lot of plants were affected at same time. I grow in greenhouse border with one spade square taken out a spade deep and filled with compost with 2 feet between plants Fed alternately miracle grow and comfrey. Just looked at the Miracle Grow box, it has a long list of minerals - but Magnesium is not one of them. Can't look at the ingredients of the comfrey feed though.

I have stopped feeding and barely watering now - just letting the fruit left to ripen before picking. Really was thinking about how to manage greenhouse for next year so the same problem doesn't occur 3 years running.

I'll have a look at the plants in the morning and see if any of them look affected but are still growing and give them a tomato feed if there are (my wife uses it for her sweat peas). I think there are a couple of gardeners delight that may be worth trying.

[MarkPelican]

I think you've got poorly plants and it could be a couple of problems at the same time. I noticed that the veins were still visible which makes me think its not blight and might explain why the plants are not dying off quickly. The stems also look healthy which they wouldn't if it was late blight.

Could it be ealy blight? This isn't as devastating as late blight or one of the wilts?

[ESBkevin]

I'm going with the blight theory, to get the very last out of the plants add some epsom salt and get a late green flourish after removing infected material. The green fruit can always be put on a windowsil later to see if they ripen as a last resort, nothing ventured etc.

[Jungle Jane]

Are they planted in the same soil for three years running? Can you dig some out once it's been washed down & replace with some from somewhere unaffected by the potato blight,so that it's kind of like crop rotation/soil rotation that's not a thing though? Thinking about next year,do you keep the greenhouse door open to help ventilation? I don't have a greenhouse,I grow my tomatoes outside but to stop it happening next year,water early in the day rather than the night,remove lower leaves to improve airflow? Unless it's the soil?

[goosander]

Had problems with the leaves going a sort of yellow and as usual thought the worst.
Watched Beach Grove and there tomatoes had the sane sort of marks etc,
Cheered me up.

[Mark_Riga]

Well, I've just emptied the bordeaux mixture out of my squirter and filled it with epsom salts will let you know how it goes.

[Penellype]

Magnesium deficiency is possible, but quite a lot of plants were affected at same time. I grow in greenhouse border with one spade square taken out a spade deep and filled with compost with 2 feet between plants Fed alternately miracle grow and comfrey. Just looked at the Miracle Grow box, it has a long list of minerals - but Magnesium is not one of them. Can't look at the ingredients of the comfrey feed though.

Next year I would substitute a tomato feed for the miracle grow - something like Tomorite, which will have magnesium in it as its specifically designed for tomatoes. The purplish blotches between the leaf veins in the middle picture look like classic magnesium deficiency to me.

[Mark_Riga]

I've found what I'm pretty certain is the culprit.
Tomato leaf mould. Mainly an issue with tomatoes grown in greenhouses I think. https://www.rhs.org.uk/advice/profile?PID=468.
Spotted it first in this document HGIC 2217 Tomato Diseases & Disorders : Extension : Clemson University : South Carolina where it's called leaf mold.