Q.What is the process and other information about the Yucca [plant being used as a wetting agent also as an emulisifier for neem oil
how does this interact in your soil, also what is its p.h. value when using for root drenching ? I have used it in both ways, an d no adverse reactions, possible p.h. drift

Certified GKH Gardening Expert
Saponins are responsible for the wetting effect. These in combination with neem oil should not have much of an impact on the soil, besides killing fungus gnats, if that is your issue here.
As long you you have the proper buffers in your soil, such as dolomitic lime, then you won't have to worry much about your pH, as it will stay close to 7.
Now, if the problem is fungus gnats, then they don't cause much damage. In fact, they eat fungus! They only show up outside of the soil when it is too wet for them to breathe, and they consume fungus that may otherwise be harmful to your plant.