// Definition
The use of ground cover (plastic sheeting, mulch, or cardboard) to prevent fungal spores from splashing up from soil onto plants during rain or irrigation, a key vector for alternaria and similar pathogens.
// From the Episode
A 17-acre Michigan farm (Rollanic crew) saw zero blight after laying plastic ground cover, while adjacent uncovered fields were heavily infected. The USDA Cornell homogeneous field with 500+ accessions used plastic and showed dramatically less septoria than uncovered experimental fields. Alternatives to plastic include wood chip mulch and corrugated cardboard rolls.