Terrain theory applies to all living beings.

The original definition of a virus is poison.

So poisons and toxins in the soil will present as "virus" and disease in the plant. Healthy soil doesn't express "viruses and disease" in its plants because its in healthy homeostasis.

Just build microbially rich, in balance, mineral rich soil that can facilitate free-flowing cation exchange and you'll have healthy plants.

Everything comes back to the root cause of toxicity and deficiency, so correcting symptoms just suppresses the issues and makes root cause solutions harder to assess and implement

Biochar, sea minerals, paramagnetic rock, molasses, kelp, healthy compost, and compost teas will all strengthen and enhance your soils "terrain" and then you won't have to waste your time diagnosing disease and pest issues.

Also electroculture helps- don't know why or how but it does