Exeter, California, July 23, 2008—Got sunscreen? These glistening walnuts do.

Farmers are increasingly applying sunblock to crops to prevent costly skin blemishes as a hedge against losses from climate change and ozone depletion.

The product, called Purshade, has an SPF of 45. It wards off the sun's harmful rays but allows for photosynthesis, which plants need to grow.

Tomatoes, grapes, and kiwis are also being field tested with the sunscreen. The substance washes off with water, according to researchers.

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