ALFALFA SEED PBODUCTION". 5 



watched a bumblebee tripping the flowers in great numbers and on 

 two occasions observed honeybees doing the same thing. 



In artificially tripped flowers Burkill found that 12 out of 34 

 tripped set seed; 50 flowers from which the standard had been 

 removed were artificially tripped and none set seed. The impact on 

 the standard, Burkill believes, ruptures the stigma sufficiently to 

 insure fertilization in about one-third of the cases. Burkill's inter- 

 esting data on the tripping of alfaKa flowers when vertical force is 

 applied to the tip of the keel are quoted in fuU on page 27 of this 

 paper. 



Hunter^ conducted observations on the relation of the number of 

 seeds per pod in alfaKa as correlated with the proximity of domestic 

 honeybees. He evidently assumes that honeybees are capable of 

 pollinating the flowers, but he does not record any observations of 

 his own on this point. Pods were compared from two fields, one 

 within half a mile of a large apiary, the other 25 miles distant from 

 any domestic bees, none of which were observed in the latter field. 

 Of pods taken half a mile from a large apiary, 87 contained 482 seeds, 

 or 5.58 per pod; 80 pods taken 25 mUes distant from any colony of 

 domestic bees produced 268 seeds, or 3.35 per pod. 



Kirchner,^ after pointing out that the data on the seK-fertilization 

 of alfalfa are contradictory, gives results of his own experiments at 

 Hohenheim, Germany. Of exposed clusters of blossoms, 54 on two 

 plants with 432 blossoms produced, August 23, 208 pods, which, 

 though they were not perfectly ripe, showed that they contained 

 636 well-developed seeds. On the other hand, 21 covered clusters 

 of blossoms on the same plants with 166 blossom^s produced only 2 

 pods with 3 seeds. He concludes that alfalfa flowers are self-sterile, 

 and suggests that Henslow's results were due to some experimental 

 error. 



Westgate,^ in 1906, presented a brief review of the work of Henslow, 

 Urban, Burkill, and Kirchner, calling attention to the disagreements 

 in the results of different investigators and pointing out the need of 

 further studies. 



Fruwirth* found that inclosed plants occasionally formed a few 

 pods at Vienna, Austria. 



Roberts and Freeman^ have recorded results of alfaKa polhnation 

 experiments at the Kansas Agricultural Experiment Station. Great 



1 Hunter, S. J. Alfalfa, grasshoppers, bees: their relationship. University of Kansas, Department of 

 Entomology, contribution 65, p. 84, 1899. 



2 Kirchner, O. tJber die Wirkung der Selbstbestaubung bei den Papilionaceen. Naturwissenschaft- 

 liche Zeitschrift fur Land- und Forstwirtschaft, Jahrg. 3, Heft 1, p. 9-10, 1905. 



8 Westgate, J. M. A method of breeding a strain of alfalfa from a single individual. American Breeders' 

 Association, Proceedings, v. 2, p. 65-67, 1906. 



* Fruwirth, Carl. Die Ziichtung der Landwirtschaftlichen Kulturpflanzen. Bd. 3, Berlin, 1906, p. 189. 



6 Roberts, H. F., and Freeman, G. F. Alfalfa breeding: materials and methods. Kansas Agricultural 

 Ejcperiment Station, Bulletin 151, p. 79-109, 14 fig., 1908. 



