4 BULLETIN 1325, U. S. DEPARTMENT OF AGRICULTURE 
fourth to three- fourths inch in diameter, which are small because of 
extremely heavy seeding) instead of seed, thus obtaining an earlier 
crop. The production of small onions for sets or for pickling is 
specialized in a few localities. The " sets " are cured and stored 
in trays. Under favorable conditions, it requires about four weeks 
for large sets to produce onions of bunching size, and from 6 to 8 
weeks if smaller sets are used. 
Onions from three-fourths inch to 1% inches in diameter are 
classed as boilers, and those from one-half to three-fourths inch are 
known as pickling onions. Onions for pickling are also produced 
by thick seeding and those below pickling size are screened out and 
may be sold as sets. The white varieties are preferred for this pur- 
pose, the Silverskin being one of the best known kinds. 
SPANISH STOCK 
Beginning about 1909, an effort was made to introduce the Spanish 
Denia or Valencia onion, a very large mild-flavored yellow type, 
in the Southwest. Seed was imported and tried out in many locali- 
ties. It was found that this could be produced as an early spring- 
crop in many parts of the South and Southwest. They are now 
grown in southern Texas, New Mexico, Utah, and the San Simon 
Valley of Arizona, and have been shipped in carload lots from at 
least one section in southern Texas. The imported Spanish onion 
matures during the late autumn and comes on the market in mid- 
winter, when its size and bright color are distinct aids in makng 
sales. The Prizetaker, the chief Americanized Spanish-type onion, 
is grown in a comparatively small way in the North by starting 
under glass and transplanting to the field. Egyptian onions, which 
are discussed further under "Imports"* (see page 55) and which 
compete most actively with the domestic Bermudas, are of the Span- 
ish type. 
SEED PRODUCTION 
California is the main seed-producing State. About 3,000 acres 
usually have been grown in the central and southern counties. 
Selected onions are set in October to February, and the seed matures 
in July or August. The seed stalks are cut, dried, and run through 
a threshing machine and a cleaner. The remaining rubbish is re- 
moved by immersing in water for a very short time to allow the 
light chaff to rise to the surface. The seed is then dried carefully. 
Common yields are 300 to 500 pounds of seed to the acre. 
COMMERCIAL ONION REGIONS 
Most of the commercial onion regions are small and the production 
is highly specialized. Half of the commercial shipped crop is 
grown on 25,000 acres. The long distance over which 40 per cent of 
the commercial onions are shipped indicates not only the excellence 
of the transportation facilities, but also the ability of this somewhat 
perishable crop to pay a very high transportation charge, taking 
one season with another. The census showed some acreage of commer- 
cial onions in every State in 1919, running from 14 acres in Nevada 
