9

Just noticed this on my store bought plant (not grown from seed). It's now fruiting, and I don't see any white spots on the leaves.

original stem

Update: 25 Feb 2016 with close up of the stems and an more distant view of the plant health

close up of affected stems

plant health

6
  • Installed imgur app so I can upload an image, but doesn't seem to be working Commented Jan 17, 2016 at 9:48
  • No need to install an app to upload the image, but I see it fine.
    – jeremy
    Commented Jan 18, 2016 at 0:43
  • I can't see a way to upload an image from an android device. So had to find a free web service, which meant installing another app. Commented Jan 18, 2016 at 1:22
  • Ah, okay. I understand
    – jeremy
    Commented Jan 18, 2016 at 4:13
  • Are you referring to the patchy ghosting on the lower stem?
    – J. Musser
    Commented Feb 10, 2016 at 2:37

1 Answer 1

6

That appears to be Southern Blight, Sclerotium rolfsii

It's a fungal disease from the soil, and affects many species of plants. You cannot cure plants infected with it. From the University of California:

  • Rotate to nonhost crops, such as corn, sorghum, rice, or small grains, for at least 2 years to reduce inoculum.
  • Deep plowing to bury plant refuse may help to destroy sclerotia.
  • Keeping the tops of beds dry in tomato fields helps reduce the disease in furrow- and buried-drip-irrigated fields.

For potted plants, I'd recommend disposing of the potting medium, and sterilizing or disposing of the container.

enter image description here

4
  • "tomato plants with southern blight have lesions on the stem at or near the soil line. These lesions develop rapidly, girdling the stem and resulting in a sudden and permanent wilting of the plant. White mats of mycelia are produced on the stem and in the adjacent soil. In a few days, tan to brown spherical sclerotia about 0.06 inch (0.5 mm) in diameter appear on the mycelial mat. The abundant sclerotia are a good diagnostic feature." I'm not seeing a white mycelium mat on the soil, no sclerotia, and no wilting though the leaves are slightly curled. Commented Feb 11, 2016 at 4:47
  • @GrahamChiu you're right.. I didn't see your picture well from my phone. Do you mind getting a closeup of the affected area?
    – J. Musser
    Commented Feb 13, 2016 at 23:47
  • I'm back at home so can provide the closer image Commented Feb 25, 2016 at 7:30
  • The plant survived to the end of summer/early autumn and I got a few tomatoes off it. But it succumbed to scale attack. Commented Jan 15, 2017 at 22:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.