What kind of tomato issue is this? physiological or pest damage?

Question

Here we have an indeterminate Brandywine tomato (if I'm recalling correctly).

It was outside in zone 6 Toronto for the better part of May, in a small container. I was on vacation and just let the rain take care of it.

It was originally started indoors using grow lights.

We've had a cold May so I suspected that this was simply shock from that.

However I did notice, and took care of, a possible springtail colony living on the plants. They were tiny yellow insects; rotund and kind of cute, and would jump at the tiniest provocation.

My question is, is this simply damage from the weather and physiological stress, or a viral/bacterial infection?

Answer 1

The Tomato Bible lists six possible reasons for purple tomato leaves: Potassium, Magnesium, and Phosphorus deficiencies, cold soil, sunburn, and Tomato spotted wilt virus. The virus is spread by thrips, which are NOT rotund or cute. Assuming your pests were springtails, then you can rule out the virus. This leaves the deficiencies and soil; personally, I doubt that it's sunburn.

You said that the plant was in a container outside for most of May, watered only by the rain, so - what did you pot it up with? How was it fertilized? If you used an adequate, balanced fertilizer then you can assume that the problem was the cold soil due to the weather. The leaves also look crispy, though, so I think you can attribute some of the problem to a too-small container watered too randomly for the plant.

Answer 2

I would agree that freezing caused it, i.e. whole plant becomes yellow and die. It looks exactly cold damage I experienced before. Either 1 night of freezing coldness or sharp temperature change is enought to cause this.

I think the spots are caused by pests; but far not serious enough to cause the plant to be so unhealthy. I also don't see any solid evidence for tomato spotted wilt virus.