http://westernfarmpress.com/tree-nuts/mechanical-pollination-rarely-supplements-bee-pollination
Elizabeth Fichtner, a University of California farm advisor in Tulare County, wrote a research paper that opens with the provocative question, “Can Mechanically-Applied Pollen Either Supplement Bees or Ensure an Almond Crop in the Event of Bee Inefficacy or Unavailability? The answer?”
The answer seems to be simply “No.”