Blistering on Tomato stems – conditions or disease? - Ask Extension
A large Chocolate Sprinkles start my neighbor got from Bi-Mart has very shallow, whitish blistering on some of the stem and leaf petioles and is afrai...
Knowledgebase
Blistering on Tomato stems – conditions or disease? #866999
Asked May 04, 2024, 10:44 AM EDT
A large Chocolate Sprinkles start my neighbor got from Bi-Mart has very shallow, whitish blistering on some of the stem and leaf petioles and is afraid it might be a disease that could spread to her other other plants. Another thought was that maybe it's a reaction to the cooler temperatures it was suddenly exposed to during the day. When you press on the areas, the blisters collapse and becomes a wet green color.
Lane County Oregon
Expert Response
This looks like it may be a physiological disorder called intumescence. It can result in these bumps, and sometimes lead to leaf curl and leaf drop. According to this Univ of Connecticut study, it may be caused by environmental conditions such as improper water balance and the quality of light. Excess moisture in the growth media combined with high humidity leads to low transpiration rates. This causes an excess buildup of moisture in the cells, so cells enlarge and erupt showing up as blisters. Light quality may also be a contributing factor. Growing plants in sunlight seems to prevent this intumescence. Here is a link to that information - https://ipm.cahnr.uconn.edu/wp-content/uploads/sites/3216/2022/12/2020odemagreenhousetomatoesfinal.2doc.pdf
Here is some more information on this subject - https://ag.umass.edu/greenhouse-floriculture/photos/tomato-plant-intumescence.
Here also is another fact sheet - https://ag.umass.edu/greenhouse-floriculture/fact-sheets/edema-intumescence
Looks like the best way to avoid this is to reduce humidity levels and grow plants in sunlight.
Here is some more information on this subject - https://ag.umass.edu/greenhouse-floriculture/photos/tomato-plant-intumescence.
Here also is another fact sheet - https://ag.umass.edu/greenhouse-floriculture/fact-sheets/edema-intumescence
Looks like the best way to avoid this is to reduce humidity levels and grow plants in sunlight.
