A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire

https://www.scribd.com/document/1023926197/Electro-culture-Gardening-for-Tropical-Climates-Heat-and-Humidity-Tips-203265

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.