Tomato Problems – Bacterial Canker

This year (2020) as every year, my plants seem to wilt with the leaves dying back. This year it seems slightly worse than normal but I keep going through cutting off the affected leaves and hoping for the best. However, it seems to have infected some of the fruit as well and some of my Summer Cider have developed brown “threads” running through the fruit. It has discoloured the fruit and it doesn’t look pleasant (although I can’t tell whether its affected the taste) but I’m not eating them out of choice.

I’ve been looking further around the web and everywhere else and I think I’ve found the answer. Its Bacterial Canker. The list of symptoms of the leaves is:

Yellow to tan patches form between veins.
Edges of leaf turn brown, with a yellow border.
Dark, sunken veins on leaves and petioles.
Wilt on lower leaves.

The fruit can appear mottled.
In the worst case, the whole plant may collapse and die.

So what has happened to cause this, particularly this year? There are a number of causes, most of which I’m guilty of so I’ll list them here:

  • Basic lack of hygiene: I grow in pots with a mix of old and new compost so if the old compost is infected then it will carry through to subsequent years (guilty so next year new compost only);
  • Strings and canes: My plants are twisted up strings. This year (out of laziness) I didn’t bother to replace the strings that are tied into the bottom of the pot so again if they were infected it will carry through (new strings next year);
  • Infected Seed: Most of my plants are from saved seed (either my own or other people’s). If the seed is infected it will again carry through. (Suggestions are to soak seeds in a weak bleach solution before sowing – I’ll try that);
  • Hot & Humid Greenhouse: The year has been up and down in temperature but there’s nothing I can do about that (I’ll have to suffer).

One thing that is interesting is that the first plant that I noticed the problem on was seed that I had saved from a plant at my allotment (a blight resistant variety that failed to what I assumed was blight but could (of course) been canker).

The solution is to “be a better grower” next year. What I hope is that the plants will crop enough to give us a good harvest of tomatoes this year.