Is This Grey Mold?

[Traveler]

Tomatoe 3 IMG-0165 (002).jpg

These 3 pictures show very light yellow colored leaves with grey spotting. This occurs predominately on lower leaves on predominately otherwise healthy plants with good new growth. However, this issue is more extreme on a couple of other plants that appear stressed out. This issue became quite noticeable when temperatures started hitting upper 80s to 90 degrees consistently.

Diagnostic help and treatment suggestions will be much appreciated.

[Uncle_Feist]

It's a nutrient deficiency.

[MissS]

It looks like phosphorus deficiency.

[bower]

The overall yellowing on a lower leaf is generally nutrient related - the plant is drawing out nutrients from those old leaves to feed the new growth, because the soil is short of their needs or they can't access it due to pH (low temperature can do that too, obviously not, in your case).
When plants start taking nutrients out of their leaf bank, they also withdraw immune support, so the leaf will also show symptoms of whatever disease is in the environment that they are susceptible to.
The spots in this case may be Stemphylium aka Grey Spot, since the larger spots have turned silvery. Turn the leaf over and look at the underside, you should see spots there as well where the leaf is eaten away and just a thin membrane remains in the middle, turns silvery, then shot hole.

[JRinPA]

Grey Mold affects the plant all at once. Grey Mold and late blight are fairly similar from a user standpoint - they just encompass the plant top to bottom and it is all dead in a week. It will affect most of the gardens in a local area. When you see it, pull the plant and bag it and trash it. Clean up the patch. And hope for a cold, cold winter to kill the spores. IMO. It has been a while, here, since a grey mold/late blight year, over a decade.

[Shule]

I'm not sure what grey mold looks like on leaves, but the plant looks as if it has sulfur deficiency. It can cause purple on leaves similar to phosphorus deficiency, but it also gives them a translucent/faded look. If I'm right, then a sulfate salt (such as potassium sulfate, Epsom salt, gypsum, etc.) should help to fix the chlorosis. I've had that problem before when starting plants, and sulfates helped. Not sure about the spots.

[Traveler]

I believe this was definitely some type of nutrient deficiency and am glad to report most plants bounce back well after I upped fertilizer quantities. I should have figured this out earlier since my in ground plants, with presumably more nutrients, were unaffected compared to my dry bags which were obviously under fed. Thanks a Sweet Million for all the ideas!