Black Powder

Kenyadenola · July 25, 2006

I have noticed on my Paul Robeson that there seems to be a black powder on the bottom of the stem, working it's way up. The powder has spread to leaf clusters with them turning black and then shriveling up and dying, but not falling off. I will try to post pictures later.

The rest of the plant is fine, the fruit that was closest to the stem where I first discovered the black powder has not been affected. Any ideas?

Thanks

Worth1 · July 25, 2006

Sounds like some kind of mold, or maybe the black death.
Is it damp inside the area where this is at.
Worth

supergirl · July 26, 2006

Passing along helpful information that Suze gave me today (thanks, Suze!) You may want to check these links and do a search for botrytis to see if it looks similar. It can cover the bottom of the stem and look dark and fuzzy/powdery.

If you think it is botrytis, I would encourage you to look through the following:
http://vegetablemdonline.ppath.corne...o_Botrytis.htm

http://aggie-horticulture.tamu.edu/t.../handbook.html
Gray Mold (fungus - Botrytis cinerea): Plants become more susceptible to this disease as they become older. It is mostly a problem in greenhouses, but it can also affect tomatoes in the field. The fungus first becomes established on dead leaves at the base of the plants. A heavy, gray growth of the fungus covers these, and numerous spores are soon found, giving the affected area a cottony appearance. Affected leaves collapse and shrink. The fungus progresses into the stem, producing cankers. Affected fruits first show a watersoaked, soft area in the points of infection. The dark gray growth of the fungus soon is seen on these spots. Regular fungicide applications should help in controlling this disease.
Botryosporium Mold (fungus - Botryosporium sp.): This fungus can often be found on greenhouse tomatoes. It superficially resembles gray mold.

Kenyadenola · July 26, 2006

That doesn't seem to be it either. There are no lesions or cankers and the fruit is just fine. I'll take a picture tomorrow and post it.

Thank you though.

supergirl · August 8, 2006

Kenya, did you figure out what it is? How are your plants doing?

I meant to tell you earlier, especially since you're not far from me -- I've had botrytris on my tomato plants (recognize it from on roses in the past, where it will cover the blossoms). I have never had anything other than dark grey fuzz on stems. The leaves wilt in a way that looks kind of like the pictures I've seen of late blight, dark and watersoaked looking, no visible fungus on the leaves that I can see, and nothing on the fruit. Stem doesn't get lesion-y until the fuzz progresses pretty seriously or I kill off the active fuzz, in which case exposed stem will have brown marks.

July 25, 2006	#1
Kenyadenola Tomatovillian™ Join Date: Jul 2006 Location: San Jose, CA Posts: 35	Black Powder I have noticed on my Paul Robeson that there seems to be a black powder on the bottom of the stem, working it's way up. The powder has spread to leaf clusters with them turning black and then shriveling up and dying, but not falling off. I will try to post pictures later. The rest of the plant is fine, the fruit that was closest to the stem where I first discovered the black powder has not been affected. Any ideas? Thanks

July 25, 2006	#2
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	Sounds like some kind of mold, or maybe the black death. Is it damp inside the area where this is at. Worth

July 26, 2006	#3
supergirl Tomatovillian™ Join Date: May 2006 Location: Palo Alto, CA Posts: 107	Passing along helpful information that Suze gave me today (thanks, Suze!) You may want to check these links and do a search for botrytis to see if it looks similar. It can cover the bottom of the stem and look dark and fuzzy/powdery. If you think it is botrytis, I would encourage you to look through the following: http://vegetablemdonline.ppath.corne...o_Botrytis.htm http://aggie-horticulture.tamu.edu/t.../handbook.html Gray Mold (fungus - Botrytis cinerea): Plants become more susceptible to this disease as they become older. It is mostly a problem in greenhouses, but it can also affect tomatoes in the field. The fungus first becomes established on dead leaves at the base of the plants. A heavy, gray growth of the fungus covers these, and numerous spores are soon found, giving the affected area a cottony appearance. Affected leaves collapse and shrink. The fungus progresses into the stem, producing cankers. Affected fruits first show a watersoaked, soft area in the points of infection. The dark gray growth of the fungus soon is seen on these spots. Regular fungicide applications should help in controlling this disease. Botryosporium Mold (fungus - Botryosporium sp.): This fungus can often be found on greenhouse tomatoes. It superficially resembles gray mold.

August 8, 2006	#5
supergirl Tomatovillian™ Join Date: May 2006 Location: Palo Alto, CA Posts: 107	Kenya, did you figure out what it is? How are your plants doing? I meant to tell you earlier, especially since you're not far from me -- I've had botrytris on my tomato plants (recognize it from on roses in the past, where it will cover the blossoms). I have never had anything other than dark grey fuzz on stems. The leaves wilt in a way that looks kind of like the pictures I've seen of late blight, dark and watersoaked looking, no visible fungus on the leaves that I can see, and nothing on the fruit. Stem doesn't get lesion-y until the fuzz progresses pretty seriously or I kill off the active fuzz, in which case exposed stem will have brown marks.