Is this disease on my tomato leaf (blackish discoloration)

johnnytwofingers · June 24, 2012

I was out pruning today and found about 3 leaves that had the discoloration shown in the picture. Is this disease of some sort? I've looked through images online and didn't really come across anything that looked quite like this.

RayR · June 26, 2012

That's not a disease, the purplish color is a buildup of anthocyanin pigments in the leaf. Other people here have been seeing purple blotches in the leaf tissue between the veins. I really think it is related to some kind of environmental stresses—weather, watering, temperature changes ect...
Other stresses like Phosphorous deficiency will cause anthocyanin buildup in the veins and on the bottom of the leaf.
Anybody else have a comment?

June 26, 2012	#2
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,466	That's not a disease, the purplish color is a buildup of anthocyanin pigments in the leaf. Other people here have been seeing purple blotches in the leaf tissue between the veins. I really think it is related to some kind of environmental stresses—weather, watering, temperature changes ect... Other stresses like Phosphorous deficiency will cause anthocyanin buildup in the veins and on the bottom of the leaf. Anybody else have a comment?