Why are foliage contact fungicides typically applied more than once?

Why are foliage contact fungicides typically applied more than once?

• A. They work for a short time.
• B. They only penetrate new growth.
• C. They only protect existing growth.
• D. They are toxic to the plant.

Answer: (C)

Foliage contact fungicides stay on the leaf surface and don’t move into the plant, so they don’t protect new growth that appears after the spray. The protective film is limited to the leaves that were present at application and can be washed off or degraded by rain, sunlight, or normal leaf growth. Because new tissue isn’t covered by that initial protection, a second (or more) application is needed to keep protecting the plant as it grows. In short, these products guard existing leaves only, which is why repeated applications are common.

Foliage contact fungicides stay on the leaf surface and don’t move into the plant, so they don’t protect new growth that appears after the spray. The protective film is limited to the leaves that were present at application and can be washed off or degraded by rain, sunlight, or normal leaf growth. Because new tissue isn’t covered by that initial protection, a second (or more) application is needed to keep protecting the plant as it grows. In short, these products guard existing leaves only, which is why repeated applications are common.