A person with a Qualified Applicator Certificate in the "Plant Agriculture" category CANNOT do what?

The reasoning behind selecting that answer revolves around the specific limitations imposed on a Qualified Applicator Certificate holder in the "Plant Agriculture" category. While individuals with this certification possess a foundational understanding of pesticide application, their authority does not extend to the commercial aspects of pesticide sales or the supervision of those who sell pesticides. This restriction is put in place to ensure that the individuals overseeing sales and distribution of agricultural pesticides have a comprehensive understanding of not only the products but also the regulatory requirements and best practices for handling and applying those pesticides properly.

In contrast, applying pesticides on public properties, conducting soil tests for pesticide compatibility, and passing on certification training are activities that typically fall within the capabilities of someone with this certification. Each of these actions aligns with the practical applications and responsibilities associated with plant agriculture. Therefore, while the holder of this certificate possesses many rights and responsibilities, supervision of pesticide sales is not one of them.