Nurseries and greenhouses

Greenhouses, shade houses and transplant nurseries, where the environment is controlled, and that's exactly why any imbalance gets magnified.

Management is different from open-field growing: high humidity favors diseases that don't take hold outside, irrigation is far more frequent and in smaller doses, and growing media don't forgive fertilizer mistakes because they have very little buffering capacity.

Nurseries add one more layer: transplant health. That's where a single pest can spread to dozens of farms at once, so control there has to be stricter than anywhere else.