Help Identifying a problem with Tomato Plants

scorplett

I'm growing tomato plants, and recently they have developed small white, roughly circular spots. I've searched through hundreds of pages on tomato diseases and pests, and can't properly identify what might be wrong.

It started on one small plant, and now seems to be appearing on other more mature plants.

They are being grown in a conservatory.
Grown from seed, Johnsons Ailsa Craig variety.


The white spots are not furry or fungal looking, they are opaque and occasionally linear, but mostly roughly round and sometimes irregular from one spot merging with another. More prominent on older leaves than on young but it's on younger leaves too.

The leaves basically look like they've been splashed with paint! *but they haven't been*

Any help in identifying this problem would be greatly appreciated.

The Sweeper

Powdery mildew?

Do you water the bases only, or do you allow the leaves to become wet?

Are they planted very close together?

As they're inside, how much air circulates around them e.g. are they exposed to a breeze?

scorplett

I don't think it's powdery mildew...
The closest thing I've seen from searching the web is septoria leaf spot, but even the pictures of that don't seem quite right.

They generally get watered at the base and the leaves don't often get damp. It's much more opaque than images of powdery mildew that I've seen and penetrates the leaf more too...

They are planted in separate containers and get moved further apart as they grow bigger, so they aren't crowding each other.

If there were obvious brown circles and a little yellowing on the leaves I would think it was leaf spot though.

Is it possible for Septoria to have a grater area of white than brown ring? I think I have seen the 'pepper grain' spot on one of the blemishes, but I can't be sure.

The Sweeper

Any visible pests on the plants? What's your potting medium?

If you have tomato plants in a very 'sterile' area, e.g. if you've grown them from seed in a tomato-specific grow bag and they're indoors in your conservatory and not near any other plants, it would be quite unusual for your plants to have picked up anything hugely exotic in terms of ailments or pests.

Septoria has been implicated as coming from seed, so you need to ensure your seed stock is from uncontaminated sources, but I'd still be suspicious if your environment is as you've described it.

Try an anti-fungal spray initially - obviously you will need to find one that won't affect the edibility of your crop - and see if that works. Also be sure you're watering correctly and feeding correctly, and perhaps allow more air at the plants.

If they keep dying, destroy the lot - don't compost the plants and don't re-use the soil.

Any chance you could post a pic of what you're seeing?

Dr Galen

powdery mildew is what first came to my mind too. Pic's would be great though then we could have a better look

craiginireland

Have you tried this: www.garden.ie/askgerry.aspx

sharonl

Could it be sun scorch? I've seen it before on my own tomato plants, when some water splashes onto the leaves and the sun then burns them and leaves white patches on the leaves like paint or something has been splashed. I just got more carefull when watering them and it went away. Didn't affect the fruits but did make the plant a little straggley for a while until new growth took over. They turned out fine. Likewise I couldn't find anything else on the net that matched and it dissappeared once I made sure not to splash them with water so I figure it was scorch through the process of elimination.

Sharon
www.plot103.blogspot.com

Munster Gal

scorplett, if you're anywhere near Cork I have about 6 tomato plants surplus to requirements that you're most welcome to take.

Gregsor

Hi folks,

I have a similar problem with my Cherry Tomatoe plant.

I only have it 3 wks now and whilst it was booming and fresh and healthy it was getting these mould like spores all over the bottom half leaves,i Googled a few theories and would "Blight" sound right?

I trimmed them all off whih were all on the bottom half and it is going fine now with no new breakouts (4 days now),and i had kept it at the window in the hall so it got medium amount of sun,no if any breeze and i only watered the soil.

I haven`t got any Tomatoe food for it yet as i wasn`t sure if it was going to survive,i just used a small bit of Baby Bio mix twice which i had made up already.

And it is full of fruit as it was when i bought it,

Greg