Which sanitation practice should be included in a greenhouse SOP?

• A. Disinfect surfaces between crops
• B. Clean only at end of season
• C. Sanitize irrigation lines and water sources
• D. Regular cleaning of benches, tools, and floors; remove plant debris; sanitize irrigation lines and water sources; control entry points; disinfect surfaces between crops

Answer: (D)

In greenhouse hygiene, stopping disease and pest spread requires a thorough, ongoing sanitation program that addresses multiple pathways, not just one action. The best practice includes regular cleaning of benches, tools, and floors to remove residue that can harbor pathogens; removing plant debris that serves as a reservoir for disease and pests; sanitizing irrigation lines and water sources to prevent waterborne spread; controlling entry points to limit introduction from workers, visitors, or equipment; and disinfecting surfaces between crops to break transmission between cycles. This combined approach tackles different sources of contamination—the surfaces themselves, organic debris, the water system, and how people and tools move in and out of the space—so the overall sanitation remains effective throughout production.

Other options are narrower. Disinfecting surfaces between crops is important but incomplete without cleaning, debris removal, irrigation sanitation, and entry control. Cleaning only at the end of the season misses ongoing contamination risks during production. Sanitizing irrigation lines and water sources is critical but insufficient on its own without addressing surface cleanliness, debris, and biosecurity measures at entry points.