Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants late season weed control

Will fluridone work in any water temp? I was going to apply it early next spring, but with the cooler water I am seeing an explosion of Pondweed. My water is really low right now, so there is little or no chance of loss through the overflow, and I should be able to maintain the required concentration easily. My water temp is 65 degrees, and with the diminished size of the pond I guess I wouldn't need quite as much. Provided I can find it, would it be appropriate to add it now?

PM n8ly and ask for sure, but I believe if the plant is actively growing, the herbicides work at all water temps. The limits I think are for the majority of weeds that normally grow only in warmer waters.

Fluridone will generally perform its portion of the equation on any susceptible plant that is actively growing - regardless of air or water temperatures. By that, I mean that it will inhibit carotene synthesis - primarily within portions of plant-growth that occur after a treatment.
However, the other half of the equation involves sunlight (duration and intensity). In essence, the coup de grâce is actually dealt by harmful wavelengths of sunlight. - AFTER the fluridone has rendered the plant vulnerable.
IMO, I doubt if growth-rates and reliable/sufficient duration and intensity of sunlight remain this late in the season to achieve the desired results on targeted submerged weeds. Then again, if the monetary risk of a treatment's potentially poor performance is relatively small (you be the judge of that), then I see no reason why you shouldn't give it a try.

Thank goodness for experts! I thought I had a good idea here, now I know better. I guess I will wait until late March or early April to apply the fluridone. When I start aeration for the 2011 season I'll add it then. As expensive as this stuff is, I want to give it every chance to work. Thanks Kelly and Rainman, I appreciate the info.

Tony