>Can anyone provide some information on carrot pollination, i.e., facts and
>sources of facts.  I have a seed producer pay $100/hive and isn't sure
>that the bees are doing the job.
 
Referring to S.E. McGregor's 1976 "Insect pollination of cultivated crop
plants" (the "Pollination Bible"; USDA-ARS Handbook 496):
 
summarizing largely from: Bohart & Nye, 1960. Insect pollination of carrots
in Utah. Utah Agr. Expt. Sta. Bull. 419
and
Hawthorn, Bohart, Toole, etc. 1960. Carrot seed production as affected by
insect pollination. Utah Agr. Expt. Sta. Bull. 422
 
he states that carrots were found to attract "334 specis of insects
representing 71 families" but that of these, the most efficient pollinators
were bees, and of these, only the honeybee was practical for management and
manipulation for commercial purposes. Bohart & Nye's recommendations were
(1) place enough colonies of honey bees to provide effective pollination
(2) avoid the presence of competing bloom (3) restrict plantings of carrots
for seed to avoid dilution of pollinators (4) plant in areas with a
diversity of native pollinators (5) take active steps to increase native
pollinator abundance - though for large commercial plantings, only (1) and
(2) are expected to be practical. The recommended density of Apis is 8 bees
per square yard, which is what is estimated to be required to achieve
saturation.
 
Doug Yanega       Illinois Natural History Survey, 607 E. Peabody Dr.
Champaign, IL 61820 USA      phone (217) 244-6817, fax (217) 333-4949
 affiliate, Univ. of Illinois Urbana-Champaign, Dept. of Entomology
          http://www.inhs.uiuc.edu:80/~dyanega/my_home.html
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82