BT and Pyrethrin which first?

brogro

brogro

Well-Known Member
I've got spider mites which I want the pyrethrin for, and I've got BT for the bud worms. Which would you spray first, would you wait days in between. Do you guys use a light soap as a surfactant with the BT. Will it kill them?

Thanks
 
P

Phytoplankton

Well-Known Member
Not sure if BT will kill mites (information on the internet is conflicting). BT has to be ingested by the bug, and it is not systemic, so it has a limited effect on sucking insects like mites and thrips. Pyrethin will kill them both, but I would not spray it if the plant is in flower. Pyrethrin is best sprayed at lights out, as it can burn leaves. If you've got mites, I'd spray for them first (you may have to do it twice, about a week apart). Then let the plant recover a bit and do the BT. BT won't burn the plant, unless it has an oil or soap added to it.
 
DCcan

DCcan

Well-Known Member
brogro said:
I've got spider mites which I want the pyrethrin for, and I've got BT for the bud worms. Which would you spray first, would you wait days in between. Do you guys use a light soap as a surfactant with the BT. Will it kill them?

Thanks
Click to expand...
Those 2 will tank mix fine, at lower application rate.

In flower, might want to use spinosad or Grandevo on mites which also tank mixes with Bt-k.
Pistils are fragile, so higher application rates may brown them. Grandevo defenitly will.
Another option is following up pesticide spray with B.bassiana mixed in the Bt-k. It will weaken survivors, infect hatchlings for the second application.

I use couple tablespoons of Regalia for sufactant in flower, seems to help the plant recover faster.
 
You must log in or register to reply here.
Top