VETCHES AND VETCH-LIKE PLANTS 475 



seed is that obtained incidentally from vetch occurring 

 naturally in grain fields. When grown alone, hairy vetch 

 should be harvested for seed as soon as the first pods are 

 ripe, regardless of the fact that flowering takes place 

 over a considerable period, and that many pods are green 

 when the first are ripened. 



The seeds of vetch are easily separated from wheat or 

 rye by means of a spiral separator especially designed 

 for the purpose. For local use, mixed seed of hairy vetch 

 and a grain is sometimes sold as harvested, but usually, 

 in such combinations, the proportion of grain to vetch seed 

 is too large. Some farmers do not cut their vetch for hay 

 until some of the seed has ripened and shattered. By 

 this means a volunteer crop can be obtained year after 

 year. The quality of the hay is injured, however, on 

 account of late cutting. On fields of hairy vetch har- 

 vested for seed it usually happens that sufficient seed 

 shatters to give a perfect stand. 



The yields of seed vary greatly according to season. 

 At the Ontario Agricultural College the maximum yield 

 obtained was 21.2 bushels to an acre, but the average of 

 9 years was only 6.8 bushels. Yields recorded by experi- 

 ment stations in bushels to an acre are : Washington, 14.7 

 and 5.5 ; South Dakota, 6.5 ; Colorado, 7.7 ; Wisconsin, 

 2.5; Mississippi, 5.57, 5.85, 7.4 and 10; Oregon, 10 

 bushels vetch and 30 bushels oats; Connecticut, 12 

 bushels vetch and 15 bushels rye. 



580. Sources of seed. Most of the seed used in the 

 United States at the present time is obtained from Russia 

 and eastern Germany. Larger quantities of it, however, 

 are being grown in the United States each year, and 

 undoubtedly sufficient for domestic use will soon be home- 

 grown seed. European seed is frequently deficient in 



