ailing tomato seedling - Ask Extension
Hello again! I have numerous tomato seedlings of various types that are doing very well (6 to 8 inches high with plenty of leaves) in a mixture of or...
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ailing tomato seedling #827882
Asked May 01, 2023, 8:54 AM EDT
Hello again! I have numerous tomato seedlings of various types that are doing very well (6 to 8 inches high with plenty of leaves) in a mixture of organic and Miracle Grow poyyong soil. I have not overwatered, in my opinion. The tomato pictured is in a small-to-modest sized pot and is ailing. What is not shown are a couple of stems with true leaves that grew, then rather quickly withered, pinched at the stem, and fell off. As you can see, the plant is stunted and the stem looks just a little bit rough. Another tomato of the same variety was doing a lot better. Only one stem pinched and fell off, but overall the plant was ok (I gave that one to my son).
What do you think might be causing this?
Howard County Maryland
Expert Response
Hi-
The darkened, pinched lower stem is consistent with rhizoctonia, one of the water molds that make up the damping-off complex. Pull out affected plants to closely examine lower stems and root systems.
https://plant-pest-advisory.rutgers.edu/damping-off-identifying-and-controlling-early-season-pathogens-2-2-2/
https://extension.psu.edu/rhizoctonia-solani-prevention-and-management-on-vegetable-transplants
Damping-off can be caused by overwatering and/or using potting soils that are too dense and hold too much water. Recycle the plastic pots or sanitize them using a 9:1, water to bleach solution.
Select lightweight (8-12 lbs./cu. ft.) soilless growing media for starting and growing transplants (contain ingredients like peat moss, coir, perlite, vermiculite, rice hulls, and compost but not "forest products").
Transplant growing media page.
Jon
The darkened, pinched lower stem is consistent with rhizoctonia, one of the water molds that make up the damping-off complex. Pull out affected plants to closely examine lower stems and root systems.
https://plant-pest-advisory.rutgers.edu/damping-off-identifying-and-controlling-early-season-pathogens-2-2-2/
https://extension.psu.edu/rhizoctonia-solani-prevention-and-management-on-vegetable-transplants
Damping-off can be caused by overwatering and/or using potting soils that are too dense and hold too much water. Recycle the plastic pots or sanitize them using a 9:1, water to bleach solution.
Select lightweight (8-12 lbs./cu. ft.) soilless growing media for starting and growing transplants (contain ingredients like peat moss, coir, perlite, vermiculite, rice hulls, and compost but not "forest products").
Transplant growing media page.
Jon
Jon - Thanks very much. I guess that this mold came on suddenly, because I thought that I had been pretty careful not to overwater. I guess not! This is the only tomato of that variety that I have. I guess I will try to replant it and hope that it will come back.
- Jim
Good luck!
