Copper Sulfate for blight?

barryla61 · June 11, 2014

Anyone use this for tomato blight?
If so as a foliar spray or sprinkle crystals around plant?

RayR · June 11, 2014

I wouldn't sprinkle Copper Sulfate around anything unless you want to kill it. Copper Sulfate is used to kill tree roots, imagine what that would do to a tomato plant. If you're talking about leaf blights like Early Blight or Septoria, the pathogen is on the leaves so any copper fungicide would be applied there. Copper Sulfate is rather harsh and is used at low concentration in a liquid mix, using too much of it can build up copper to toxic levels in the soil over time.
I haven't used coppers in some years but my favorite is Copper Soap (copper octanoate)fungicide. Much safer to use, very low copper content and pretty effective as a preventative and control. See Concern Copper Soap Fungicide, Soap-Shield Flowable Liquid Copper Fungicide, there are a bunch of others. If you buy it, buy a concentrate, not an RTU. RTU is not very cost effective. A lot cheaper to mix your own from concentrate.

June 11, 2014	#1
barryla61 Tomatovillian™ Join Date: Jul 2011 Location: Bedford, VA Posts: 257	Copper Sulfate for blight? Anyone use this for tomato blight? If so as a foliar spray or sprinkle crystals around plant?

June 11, 2014	#2
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,466	I wouldn't sprinkle Copper Sulfate around anything unless you want to kill it. Copper Sulfate is used to kill tree roots, imagine what that would do to a tomato plant. If you're talking about leaf blights like Early Blight or Septoria, the pathogen is on the leaves so any copper fungicide would be applied there. Copper Sulfate is rather harsh and is used at low concentration in a liquid mix, using too much of it can build up copper to toxic levels in the soil over time. I haven't used coppers in some years but my favorite is Copper Soap (copper octanoate)fungicide. Much safer to use, very low copper content and pretty effective as a preventative and control. See Concern Copper Soap Fungicide, Soap-Shield Flowable Liquid Copper Fungicide, there are a bunch of others. If you buy it, buy a concentrate, not an RTU. RTU is not very cost effective. A lot cheaper to mix your own from concentrate.