Scott from San Jose, Ca writes
Is there a reason the recommended dosage of Dominion 2L for whiteflies in a tree is roughly 1/4 to 1/2 the amount of Imidacloprid as compared to that in the recommended dosage of Bayer Tree & Shrub? Doing the math for the recommended dosage for whiteflies in a tree of .1 to .2 oz of Dominion 2L per inch diameter (at 21.4% potency) I get .0214 to .0428 oz of Imidacloprid per inch. Doing similar math for Bayer Tree & Shrub granular treatment recommended dosage, the actual Imidacloprid is .0767 oz of Imidacloprid per inch of diameter. (Detailed calculation: Bayer recommends 1/4 cup per inch of circumference which is 6.28 oz by volume per inch diameter which given each oz of the Bayer product by volume is about 1.11 oz by weight you get 6.97 oz by weight. At 1.1% potency I get the .0767 oz Imidacloprid per inch of diameter.) Don't get me wrong, if the lower recommended dosage of Dominion 2L works as well, then I'm happy, but I'd like to understand why the difference in recommended actual Imidacloprid dosage.
Dominion 2L is a professional-grade product so has a higher percentage of active ingredient. The Bayer/Bio Advanced line is their consumer so it would not have a higher percentage available in this line. They have the Merit 2F for their pro line which Dominion is a generic version of. Granules require a higher percentage of active ingredient as they do not cover the entire area, granules are spaced on the ground in more concentrated amounts while a liquid that would be better able to get down into the soil for the roots to absorb and is more thoroughly applied over the area. Granule systems are really only good for shallow roots trees/shrubs as their feeder roots are closer to the surface.
Answer last updated on: 07/25/2022
