How infectious plant diseases spread across managed and natural ecosystems?

Interesting question whose answer is complex because there are so many factors (both biotic and abiotic) involved.

Our work has shown that cover crops can enhance the soil and field environment to favor beneficial insects (“Managing Pests with Cover Crops” in book “Managing Cover Crop Profitably”). Under natural ecosystems or under agricultural systems managed to increase biological diversity (e.g., by using cover crops), there is increased number of organisms that compete with pathogens and insect vectors.

We have found (unpublished data) that tomato grown on cover crop residue had reduced incidences of Tomato spotted wilt (viral disease transmitted by thrips) compared to tomato grown in bare soil.