Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Fluridone usage rates ppb

Hopefully someone can answer this question. I am puzzled. I have read that the applying fluridone at 70 ppb will be very effective at controlling Lemna. My question is why does the ppb have to be so high compared to controlling a weed such as curly leaf or Eurasian millfoil when treated at 4 ppb when treated as a whole lake treatment in early spring? Why such a huge difference? If I treat my pond I would consider it a whole pond treatment? I could save a lot of dough if I was able to treat a 4 ppb vs 70 ppb. I know I should probably call the producer but thought I would try it here first. Thanks

weedsnomore - It has to do with different plants species have different sensitivities to the chemical. Absorptive nature, exposed foliage surface, and individual chemical sensitivity all play a role. Contacting the manufacturer would also be a good idea for specifics.