10 
BULLETIN 1289, U. S. DEPARTMENT OF AGRICULTURE 
The variety known as winter vetch is similar to Oregon vetch and 
is the only commercial variety to be obtained from Europe that is 
likely to prove of value for this region. It may be that in the past 
the unfavorable results of many tests of common vetch in the 
Southern States have been due to the use of unsuitable varieties, as 
it is probable that in most cases imported seed was used. 
/OO 
23 
3 /O /3 20 23 30 33 *0 +3 30 33 60 
Fig. 3.— Diagram showing the percentage of hard seed in Vicia sativa var. macrocarpa and the decrease 
with age 
VIABILITY OF SEED 
The number of years that seed of common vetch will retain its 
vitality depends to some extent upon the conditions under which it 
is kept. Under average conditions it will diminish in vitality but 
little in six to eight years. In so far as tested, there is no difference 
in varieties in this respect. Table 2 gives the results of tests that 
have been made with seed varying in age from 1 to 20 years. The 
