A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire
https://cristiangugz086.bearsfanteamshop.com/electro-culture-gardening-in-greenhouses-setup-and-climate-considerations
A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire, positioned near crops to capture atmospheric ions and gently influence local electrostatic conditions.