Selective admission of bees to cucumber blossoms (through use of a field screening procedure) resulted in production of fruit yields roughly proportional to the length of time the bees were admitted and to the field activity level of bees during that time. In this experiment, the continuous increase in fruit yields with increased exposure to bee pollinating activity suggested that bee populations were inadequate to insure maximum yield on a once-over (single) harvest basis. The introduction of a supplemental source of bees tended to support this theory, but technical difficulties caused limitations of the differential effects and the data were not subject to statistically valid measurement. In general, however, the experiment upheld previous reports that the honey bee is extremely important to the pollination of the cucumber crop and that the major portion of bee pollinating activity occurs during the mid-day period.

Heinz Michels supplied bees for the experiment and information on their management. Assistance was also provided by Obata Brothers, Gilroy grower-cooperators; and F. J. Hills, Extension Agronomy Specialist, University of California, Davis.