16 



BULLETIN 75, U. S, DEPARTMENT OF AGEICULTUEE. 



Table VII. — Effects on seed setting of visits of insects without tripping the alfalfa flower 



at Chico, CaL, 1909. 



Description of flowers. 



Plant. 



Number 



of 

 flowers. 



Pods set. 



Number. 



Per cent. 



Young flowers untripped and protected from insect visitors 



Old flowers untripped and protected from further insect visitors. 

 Youn? flowers developed under natural conditions 



It 



B 



109 

 34 

 40 



311 

 47 

 33 

 52 

 70 



3 

 

 1 

 5 

 

 

 31 

 18 



2.74 

 



2.5 

 1.6 



59.61 



Old flowers developed under natural conditions 



25.71 







These results indicate that a small percentage of jflowers set pods 

 without insect visitors and that insect visitors that do not trip the 

 flowers have no effect. 



EFFECT OF POLLEN FROM DIFFERENT SOURCES. 



To determine the relative effects of self-pollination and cross- 

 poUination, a series of experiments was conducted at Pullman, Wash., 

 Chico, Cal., and New London, Ohio. Using the same female parent, 

 pollen was appHed to the stigma {a) from the same flower, (jb) from 

 another flower on the same plant, and (c) from another plant of the 

 same variety. The results are presented in Table VIII. 



Table VIII. 



-Pods and seeds produced by alfalfa flowers when fertilized by pollen from 

 different sources. 



A.— When Pollinated from the Same Flower. 





Year. 



Plant 

 No. 



Number 



of 

 flowers. 



Num- 

 ber of 

 pods. 



Flowers 



bearing 



pods. 



Number 



of seeds. 



Locality. 



Total. 



-Vverase 

 per pod. 



Chico, Cal 



1909 

 1909 

 1910 

 1910 

 1910 

 1910 

 1912 

 1912 

 1912 

 1912 

 1912 

 1912 



3399 

 5099 

 1 

 3 

 5 

 7 

 1 

 2 

 3 

 4 

 5 

 6 



65 

 95 

 43 

 29 

 61 

 50 

 33 

 26 

 13 

 27 

 32 

 39 



17 

 34 



9 



2 

 42 

 19 



1 

 16 





 13 

 12 







Per cent. 

 26.0 

 35.7 

 20.9 



6.9 

 68.8 

 38.0 



3.0 

 61.5 







48.1 

 37.5 











Do 







■Plillmari Wnsh 



11 

 2 



55 



34 

 



24 

 



26 

 6 

 



1.2 



Do 



1.0 



Do 



1.3 



Do 



1.8 



New London, Ohio. 







Do 



1.5 



Do 







Do 



2.0 



Do 



.5 



Do 











Total. 



513 



165 





158 





Average 







32.1 



1.4 

















