8 



BULLETIN 104, L\ S. DEPARTMENT OF AGRICULTURE. 



The flowers of a beet spike open successively ; therefore, few at any 

 one time attain the same stage of development. This fact not only 

 limits the number of available buds on each spike, but also may 

 reduce the percentage of effective hand pollination as much as 50 per 

 cent. The above results may therefore be considered not only posi- 

 tive, but surprising. The complete notes of the results of this experi- 

 ment are shown in Table II. 



Table II. — Pollination of beetfotvers — experiment of August 26, 1911. 





Description. 



Flowers. 



Seeds. 





Spike. 



On 

 spike. 



Sterile. 



Num- 

 ber. 



Per 

 cent. 



Remarks. 





Check 



do 



22 



14 

 36 

 22 

 10 



22 



14 

 36 

 22 

 10 





 



8 













 

 

 



Not emasculated; spike dry and 

 brown. 

 Do. 



No. 2b 



do 





No. 2c 



..do... 



Do. 



No. 3a 



do 







Total 



Thrips admitted . . . 



green. 





104 



104 













No. 3b 



No. 3c 



7 



5 



2 



28.8 





No. 4a 



No. 4b 



Thrips admitted. . . 

 do 



12 

 35 



10 



28 



2 



7 



16.66 

 20.00 







Total 



Wild beets. 

 Check 







54 



43 



11 



20.37 



For the entire set. 



No. 1 













No. 2 



do 













No. 4 



do 





All. 













No. 3 







Do. 



No. 5 



do 











Do. 



No. 6 



do 











Do. 



No. 7 



do 











Do. 



No. 8 



do 



24 



19 



5 



20.83 











During the following season two similar experiments were carried 

 out. The first experiment was made on June 26, 1912, when the 

 plants were flowering abundantly. On this date two spikes were 

 prepared as already described, except that the additional precaution 

 was taken to spray thoroughly all parts of the flowers and spikes 

 with water from an atomizer to remove any thrips that might be 

 hidden there. Three days later thrips were collected and transferred 

 to the bags. A month later complete notes were made, with the 

 results shown in Table III. 



On July 12, 1912, the second experiment was started in the same 

 manner with three spikes, and a month later the data shown hi Table 

 III were secured. 



These experiments demonstrate that thrips transferred from one 

 flowering beet to another may carry sufficient pollen on then' bodies 

 to effect fertilization. 



