Question
QUESTION: Hi Elyse, your mildew mix did wonders for my container tomatoes; it's halted the mildew on all the plants! I seem to have a new problem with one tomato however, I haven't a photo because it's too difficult to get the camera into the leaves.  Symptoms:

- On lower leaves and going up
- pale yellowing of the leaves
- stem seems to have little dark patches on them (almost to the consistency of dirt but embedded IN the stem) - spreading upwards
- once all the foliage on the stem is 'yellowed', the stem becomes quite 'loose' (as if rotten) and i can pull the stem out with barely any resistance.  

Getting quite worried!

Wen

ANSWER: Wen:
Sounds like fusarium wilt or another fungal disease. There isn't anything you can do about it, destroy the plant and change the soil in the pot. You can sterilize the soil by putting it in a plastic bag in the sun for a month, if you want to reuse it. Don't put it in your compost. Scrub out the pots with a stiff brush and sterilize them with bleach before repotting.

Elyse

---------- FOLLOW-UP ----------

QUESTION: OH no!  I'm devastated!  Is FW airborne?  Can it affect my other plants (also in containers)?  THey are tomatoes too, and capsicums and basil.

From a purely clinical pov, could you also please let me know what causes the dark / black patches on the stems?  

Thanks (sorry about the double posts - I had attached a photo in the other one)

Answer
Wen:
The fungus is found in the soil. It can affect other plants in the same family, which would include your capsicums. The basil shouldn't be bothered by it. Sorry I missed the photo in the other post.

I'm not quite sure how to answer your other question. The dark patches on the stem are due to rot, the fungus moves up the stem along the same pathway as water. If you're looking for the biological/chemical reactions, I can't say.