Greenhouse glazing refers to

• A. The frame material only
• B. The property that blocks light completely
• C. The shade cloth used to reduce sunlight
• D. The material covering the greenhouse that allows light transmission

Answer: (D)

Glazing is the material that covers the greenhouse and lets light pass through to reach the plants. It’s the covering, not the frame, and not a shade cloth or any material that blocks light. The glazing material—common examples include glass or clear plastics like polycarbonate or film—is chosen for how well it transmits light, as well as how it diffuses that light, insulates, and lasts under climate conditions. Shade cloths are used to reduce sunlight and are separate from the glazing, while a covering that blocks light would defeat the purpose of a greenhouse.