Are diseases present because pesticides were not applied in time?

Do people or animals get bacterial infections because they have an antibiotic deficiency?

Do plants get disease infections because of a pesticide deficiency? If not, why do we apply pesticides before the organism is even present?

Come to think of it, plants do absorb antibiotics synthesized by soil microbes, and they help prevent possible infections. Maybe plants do become infected because of antibiotic deficiencies after all?

In that case, what produces the antibiotic deficiency?

That would be dysfunctional soil biology. Which is likely dysfunctional because of all the pesticide applications the soil has been exposed to.

Perhaps killing the microbes that protect our crops isn’t such a good management strategy.