THE ENEMIES OF ALFALFA 209 



with the parasite, has made the work hard and the results 

 obtained unsatisfactory. There are a number of methods 

 by which dodder may be spread through a field. As soon 

 as it becomes thoroughly established on a host plant, the 

 many little branches, waving about like the shoot pro- 

 duced from the seed, attach themselves to other plants, 

 and thus the colony is increased in size. In legumes, the 

 host plant first attacked soon dies, but before this occurs, 

 the parasite has become firmly established on adjoining 

 plants and is reaching out and completing the colony. 

 As soon as a host dies, the dodder also perishes, but before 

 this happens it is very likely to have blossomed and seeded. 

 *'In the operations of mowing, tedding, raking and 

 drawing the alfalfa hay, these little colonies are spread 

 about the fields by the machines and the workmen, and 

 on the horses' feet. The sale of infested hay is a prolific 

 means of dissemination. Hunters and pleasure seekers, 

 walking through the fields, notice the peculiar corn-silk- 

 like growths and often, by picking up particles of it which 

 are soon cast away, establish new colonies. The flower 

 is very peculiar and attracts the attention of people pass- 

 ing, who are apt to pick them together with some of the 

 maturing seed, and scatter these over the fields. In a 

 pastured field, the animals spread the seed to some extent 

 while moving from place to place in feeding. The most 

 serious menace, however, is from the purchase of impure 

 seed; farmers should always be absolutely certain that 

 the alfalfa seed which they are buying is thoroughly 

 recleaned and that no small weed seed is to be found in It. 

 One should never sow clover or alfalfa from a field or 

 even from a locality in which dodder is known to exist. 



