60 ANNUAL REPORTS 01 DEPARTMENT 01 AGRICULTURE, 1951 
made by the bees, based on calculations from the seed obtained. 
i eached 275, l 1 h >,i h m i a n acre, a new record. 
Alfalfa within Mil; !n range of a 7-acre field of red clover containing 
28 colonies of bees attracted large numbers of field bees of the co • 
awaj from the red clover. There was some indication thai the firsl 
clover blossoms were not so attractive i<> the bees as were later ones. 
V 3its to the clover increased when pari of the alfalfa was cut. 
Bees Selective in Choice of Pollens 
In comparative tests on the attractiveness to bees of ground-ui 
loads of gumweed pollen, alfalfa pollen, and commercial soybean 
Hour, gumweed pollen was favored over soybean flour. The alfalfa 
pol Ifii \\ as relat ively unatt ract ive. 
Moving Bees Means More Seed 
In 1950, in a sampled portion of an alfalfa field of 132 acres in 
( Jali fornia, the est i mated acre yield was 1,800 pounds of thresher-run 
seed. Only slightly more than three colonies of bees an acre were 
used. The colonies, however, were moved in and oul of the field, 
mostly at intervals of 7 to LO days, although during pari of the time 
the bees were moved every night. The estimated yield by this met bod 
showed an increase of 680 pounds of thresher-run seed over the yield 
in L949, when slightly more than five colonies an acre were provided 
and all colonic- were left in their original position for mosl of the 
60-day pollinaf i<>n period. 
Ladino (Mover Yields Only Pollen lo Visiting Bees 
Studies at Davis, Calif., showed that the chief activity of bees on 
ladino clover is pollen collection. The presence of two or three bee 
\ isitors to t he square yard seemed i<> insure complete pollination. All 
blossoms visited closed permanently at nightfall. Other studies on 
ladino blossoms protected from pollination by boney bees showed that 
they have no visible nectar for 2 t<> •"> hours after dehiscence, so that 
pol len i- a \ a liable in adi a nee of nect ar. 
Bee-Collected Pollen Usable lor irtificial Pollination 
Experiments, in cooperation with tin- Horticultural Department of 
the Uhiversitj of California, showed that apple pollen stored in a dry- 
ice freezing chamber will remain viable for a year, Fruit was ob- 
tained from apple blossoms t<» which the stored pollen had been ap- 
plied b) both wet and dry carriers. The fruit set ranged from 1 to 
•J.- percent. The apple- had plump, normal appearing seeds, but in 
number the} averaged onri about one-third of a full complement. 
Two freshly hand-collected samples of pollen from Delicious apple 
onu gave a 26 and a 27 percent set, respectively, and fruit n it h a 
i pa 1 1 v full complement <d seed. 
Experiments were also conducted on nnstored bee collected pollen 
from almond, sweet cherry, pear, and apple tree-. 'The pollen, after 
being trapped from the colonies, was dried, after which one portion 
\i i vd with lycopodium spores and another with sugai sirup. 
