A whitewash made from clay (yup, clay!) may improve the possibilities of
organic fruit production. At least is has the potential to greatly reduce
pesticide use, because it makes a physical barrier for insects. It also
protects fruit from damaging spectra of light, can serve as a frost barrier
and has many other advantages that are yet unexplored. Best of all, it's
nontoxic (some of the pills you take have kaolin clay as a base). I expect
it should be nontoxic to bees.
The full story:
http://www.ars.usda.gov/is/AR/archive/nov00/white1100.htm
Dave Green
The Pollination Home Page: http://pollinator.com