You really never want to use a product in any way other than the label directions - the wettable powder is added to water and applied as a drench, or injected into soil and you would void the results and possible environmental impact doing otherwise.

You also aren't considering that imidacploprid may photo-degrade rapidly, exposed to light on soil surface and you could be wasting your product, reducing impact on your target pest.

No...........it is illegal to use any pesticide in any way not consistant with labeling. Imidicloprid is persistant. IOW it is a systemic professional growers are limited to using on many crops any more frequently than once a growing season. To unleash powder into the ecosystem to be washed off and translocated in rain or irrigation is not at all a good idea. When using wettable powder responsibly, one knows the exact dosage one is distributing and keeping it in one location. There is no way you can even assume to know the dose you are applying if you're sprinkling a powder designed to be suspended in liquid. This is exactly why I am so dismayed to see this particular compound unleashed to the general public. Scares the beejeebers out of me.

isnt it the active ingredient of bayer tree and shrub systemic ...

just use that product... ACCORDING TO LABEL INSTRUCTIONS

ken

Let me clarify. I wasn't proposing to fling a bag of powder in the air and hope for the best. The thought was to rake back leaf duff around the trunk, deposit WSP and re-cover. No photodegradation or wind-drift. Since the soil here is very loose and permeable, runoff is also not an issue. A precisely measured dose would be applied to each tree. The slowed mobilization of pesticide might actually improve root uptake vs. downward loss.

Liquid drench would be much easier for large-scale commercial applications. For relatively few trees, emplacing powder would seem to make less fuss. And yes, I do know how to handle chemical powders, not that this stuff is particularly harmful for people.

WSP application a few inches below the soil surface seems to me not much different from the Kioritz concentrate injection recommended by Bayer themselves (e.g. http://www.gainvasives.org/hwa/imidacloprid.pdf), trading some inconvenience and time for having to acquire and maintain expensive equipment for rare or single use. So I'm just wondering if anyone knows of a specific reason why this might not work, beyond "follow the directions." After all, this is how new techniques are developed in the first place!

First off, if the horticultural oil did not address the adalgids, it wasn't applied properly.

OK, you have not really identified the product which you wish to use containing the imidicloprid. Depending on which product, there may be a variation of how much of it is active ingredient. There are some products with dry application of the soluable powder already approved, followed up by an irrigation. Here's the rub. I'm curious as to how you are going to measure out that 'precise dose' of active ingredient for twelve shrubs. It's going to be pretty miniscule because I know how much is the proper dose for an acre and it's quite small. A bucket and a hose to put water in it are not exactly pieces of expensive equipment. Your nemesis will be to ascertain the dosage and you'll have to do that regardless of whether you wet the powder or not. That is unless you don't intend to be that precise.

If your soil is very loose and permeable, it can and will move through the soil and needs to be kept away from the water table.......... you need to know this stuff's greatest risk is ground water contamination and much more care needs to be taken applying it outside than in a greenhouse situation. It is very toxic to bees and invertebrates and quite persistent in water. Once you apply it, you can't take it back.

So basically how you propose to do this is not a 'new technique'. It's on the label of the appropriate product but you just haven't researched it enough to find the product and read the label. And new techniques are not developed safely out of the laboratory environment where chemicals are involved. I've been a certified pesticide applicator for two decades. Use whatever product you are using exactly per the label. There is a reason, it's specific enough, that's the only way the product is safe and environmentally responsible. Easy concept.

I think that this discussion is worthy of forwarding to Bayer. This issue has come up a few times in these forums....people trying to take short-cuts or save money by inventing and justifying an off label use of Imidacloprid. Each and every one of these people ask our opinions, and when they get answers that they don't understand nor like....they get defensive.

The idea that new techniques are discovered by homeowners wanting to do it the easy way is preposterous. To be factual...there ARE no new techniques for each formulation. Years of research have already gone into this product...long before ever getting into the hands of the retail consumer.

You need to use your product the right way, at the right time of year, and at the right rate of application. If it seems too burdonsome for you then hire someone with the equipment to accomplish the task for you.

Sorry if I seem impatient, but you could be my neighbor. I'm sure that you are someone 's neighbor.

I take it that you are considering using Merit 75% WP?

Recent research has found that Imidacloprid is extremely toxic to bees and other pollinators. Many people think that because this poison is not sprayed around it has no adverse affect on them but apparently it does get inot the pollen of plants in large enough quatities to cause severe problmes with those that need the nectar or pollen from many different plants. If it adversely affects bees it may well also adversly affect hummingbirds.