204 



Kansas State Board of Agriculture. 



before the flower is ready for tripping. The method we have generally 

 followed, however, in crossing alfalfa, is as follows: 



When the flowers are ready to be tripped, a pin is inserted between the 

 standard and the keel, and the latter is gently depressed. Instantly it 

 opens, and the column of pistil and stamens flies up. It is not allowed 

 to strike the standard, but is turned to one side past the standard. The 

 pin is then removed, and the pollen' is washed out of the anthers and off 

 the surface of the stigma by means of an atomizer spray, a binocular lens 

 being worn to facilitate observation of the work. The stigma is now 

 ready to be pollinated with pollen from another flower, which being done, 

 the flower head is enclosed in a parchment paper bag, tagged, and left 



PIG. 183. Plant of alfalfa enclosed in cage to prevent access of insects to flowers. 

 Used in work of crossing alfalfa by hand. 



undisturbed until the seed sets and the pod begins to grow. The bag is 

 then removed, in order to prevent overheating and the growth of mold 

 Such, briefly, is the process of crossing alfalfa by hand. It is a slow 

 and tedious operation, requiring great skill and care in the manipulations. 

 A more rapid method of securing alfalfa hybrids, although the exact 

 parentage can never be ascertained, is to set plants of the two strains 

 which it is desired to cross alternately in the same row, depending on the 

 visits of insects to secure cross-pollination. Of course a great many 

 seeds will be self-pollinated many more, usually, than will be crossed. 

 The problem will be to distinguish the hybrid plants from the others. No 

 distinctions, of course, can be detected in the seeds. However, all the 

 seed ripening on the plants of such a mixed row should be harvested and 



