THE RYEGRASSES 7 



itself for 2 years, although occasionally when the percentage of peren- 

 nial ryegrass in common ryegrass seed is rather high, perennial rye- 

 grass plants will remain for several years. As stated previously, 

 perennial ryegrass is not popular in lawns. 



Seed Production 



Practically all the seed of common ryegrass is produced in the Willam- 

 ette Valley in northwestern Oregon. In recent years a few counties 

 in Kentucky have been producing a quantity of ryegrass seed — pre- 

 sumably Italian. Harvesting practices are the same as for small 

 grains. When cut with binders, stationary threshers are used for 

 threshing. When the crop is cut with a header and windrowed, or 

 when allowed to stand until mature, combines are used for threshing. 

 As the seed shatters easily, larger yields are secured by cutting with 

 the binder or header when the seed is in the early harcl-dough stage. 

 Combining the standing crop when the seed is ripe enough to thresh 

 satisfactorily often results in heavy losses from shattering. To pre- 

 vent shattering, there has been a tendency to harvest the seed with a 

 combine while it is still in a slightly immature stage. Such seed when 

 sacked or piled in large quantities often heats and molds with the pos- 

 sibility of reduced vitality. 



Seed yields vary considerably. On the better soils from 1,200 to 

 1,500 pounds of clean seed are obtained; average yields are 600 to 700 

 pounds an acre. Seed production on a large scale has been carried on 

 in the Pacific Northwest for the past 14 years. Production varies 

 widely from year to year as shown in table 1 , with the production of 

 perennial ryegrass seed steadily increasing. 





Table 1 



— Production of ryegrass seed in the Pacific 



Northwest 





Year 



Common 



Perennial 



Year 



Common 



Perennial 



1934 



Pounds 



9, 000, 000 

 6, 496, 000 

 12, 898, 000 



Pounds 



112, 500 

 130,000 

 200, 000 



1937 



Pounds 

 7, 480, 000 

 18, 300, 000 



Pounds 

 425, 000 



1935 



1938 



932, 000 



1936 









Very little seed of pure Italian ryegrass or perennial ryegrass is 

 grown in the United States, which is unfortunate, as imported seed 

 generally sells at a premium. 



The amount of Italian and perennial ryegrass imported into the 

 United States decreased rapidly from 1926 to 1936. In 1937, however, 

 an increase in imports was shown, partly owing to the inadequacy of 

 the domestic seed supplies in addition to the increased demands for 

 pasture and lawn purposes. The figures given in table 2 show a 

 shift in the amounts of Italian and perennial ryegrass seed imported. 

 From July 1, 1925, to June 30, 1938, importation of perennial ryegrass 

 was consistently greater than that of Italian ryegrass. Within the 

 last 2 years, however, the importation of Italian ryegrass has increased 

 materially because of the place it has made for itself in the annual 

 pasture program and for winter-lawn purposes. 



