RED CLOVER 403 



make the seed crop at a time when the fly is not 

 abundant. 



The clover-hay worm (Hypsopygia costalis). This is 

 the larva of a small, brown moth which feeds on the dry 

 hay in storage. Most of the damage is usually done near 

 the bottom of hay stacks or mows. To some extent, it 

 may be prevented by salting the hay, especially near the 

 bottom of the stack. Where hay is stacked in the field, 

 the injury is much lessened by building the stacks on a 

 foundation of logs, or other platform. 



474. Improvement of red clover by breeding. In 

 recent years there has been much interest in the subject 

 of breeding improved red clover. Individual plants differ 

 greatly and this permits of selection for numerous dis- 

 tinctive characters. More or less work of this kind has 

 been conducted at the experiment stations of Tennessee, 

 Illinois, Iowa, Indiana and North Dakota and by the 

 United States Department of Agriculture. In Europe 

 similar breeding researches have been undertaken in 

 Sweden, Denmark and Switzerland. 



Breeding red clover presents difficulties in that cross- 

 pollination is required and that, therefore, at least two 

 individuals are necessary to start a strain. Furthermore, 

 isolation is then required to prevent miscellaneous cross- 

 pollination. 



Mass selection is much simpler, especially where an 

 unfavorable factor eliminates a large proportion of the 

 population. In this way a strain resistant to anthracnose 

 has been developed at the Tennessee Experiment Station. 



Card in Rhode Island found that the nitrogen content 

 of different individual plants ranged from 2.86 per cent 

 to 4.62 per cent. This suggests the possibility of select- 

 ing strains with high protein content. 



