NOTES ON POLLINATION OF RED CLOVER 
361 
lectrng those plants with the least tendency toward infertility. ’ ’ 
Quoting from the paper, “Red Clover Seed Production,” the 
results published by previous investigators on cross pollination 
and self-pollination of red clover do not agree. Frandsen and 
Fruwirth also show that pollen must come from an entirely 
separate plant in order to fertilize the ovules of red clover 
flowers. 
The relative efficiency of the bumble bee and honey bee as 
cross pollinators of red clover has also been discussed by scien- 
tific investigators as well as by agricultural papers and bee 
keepers. Bee men generally agree that the Italian races of honey 
bees can extract nectar from red clover flowers. Little, how- 
ever, has been said about the ability of the honey bee to collect 
pollen from red clover. 
In view of the above diverse opinion in regard to self-pollina- 
tion and cross pollination of red clover, a number of experi- 
ments were outlined in order to determine (1) whether red 
clover flowers were self fertile, (2) if self fertile, whether any 
effective method of self pollination could be found which would 
be applicable for use on a field scale; and (♦.3$ the relative effi- 
ciency of the bumble bee and honey bee as cross pollinators of 
red clover. 
In the matter of the bumble bee as a cross pollinator of red 
clover, in addition to the foregoing data the following additional 
data will be of interest. 
TABLE GIVING THE RESULT OF EXPERIMENTS CONDUCTED 
IN 1911 AND 1913. 
Year 
Location 
Bumble Bee Cage 
.Field Conditions 
No. of Heads 
Average 
No. of Heads 
Average 
1911 
Ames _ _ 
311 
' 30.4 
1302 
52.5 
1913 
Ames — _ 
970 
13.3 
79 
12.9* 
(First crop) 
1913 
Le Mars 
242 
49.7 
244 
5.3* 
(First crop) 
1913 
Harpers Ferry 
250 
46.6 
237 
ffl* 
(First crop) 
jj( . . 
(Second crop) 
220 
20.3 
244 
45.0 
1913 
Essex 
200 
34.5 
224 
36.1 
(First crop) 
1913 
Knoxville 
245 
50.5 
250 
54.9 
(First crop) 
General average 
28.5 
41.0 
*It is not surprising- that the average is smaller in bumble bee cage for 
reason that the bumble bee does not work as well under restraint. 
