6 BULLETIN 209, U. S. DEPARTMENT OF AGRICULTURE. 
purposes, together with grape immigrants from all parts of the world 
introduced by the Office of Foreign Seed and Plant Introduction. The 
first plantings were made in the spring of 1906, and the collection here 
already comprises 308 resistant and direct-producing sorts and 141 
Vinifera varieties grafted on resistant stocks. 
SMALLER VINEYARDS. 
In addition to the main plantations, outlying vineyards of 10 acres 
each have been established to test varieties at different altitudes, at 
varying distances from the ocean, bays, and other bodies of water, 
under different climatic and other conditions, and on the leading types 
of vineyard soils not found at the Oakville, Fresno, and Guasti 
vineyards. 
BRAWLEY EXPERIMENT VINEYARD. 
The Brawley Experiment Vineyard was established in the spring of 
1911 on the New River, 1 mile west of Brawley, Imperial Co., CaL, on 
the property of Mrs. Mabel Oakley, about 110 feet below sea level. 
(See PL II, fig. 2.) The soil, Imperial loam, is sediment brought 
down by the Colorado River and deposited in strata either while the 
area was still submerged or from the overflow waters as they spread 
over the plain. Before irrigation these strata, varying from 1.1 to 
2 or 3 inches in thickness, are quite hard and look like shale, but water 
softens them readily. This soil after irrigation is a sticky reddish 
loam, a little heavier than a silt loam, having a depth of 4 to 6 feet and 
resting on a clay or clay-loam subsoil, which in turn is underlain by 
alternate strata of lighter and heavier material to an indeterminate 
depth. The surface is usually smooth and level and almost devoid 
of vegetation. The soil often contains considerable organic matter 
and when irrigated is productive. Alkali is found in all of it and 
often greatly in excess of what even the most resistant plants can 
stand, thus making much reclamation work necessary. This soil is 
by far the most extensive type in the Imperial Valley. It extends 
from about the middle of the eastern boundary across in a northwest- 
erly direction into the Salton Sink. A large part of the area west and 
southwest of Imperial and large tracts between Mesquite Lake and 
the Mexican line are of this type of soil. 
The Imperial Valley is said to be the earliest fruit-ripening district 
in the United States, and as no phylloxera have been located in it the 
plantings of 280 grape varieties in this vineyard are all Vinifera. 
COLFAX EXPERIMENT VINEYARD. 
The Colfax Experiment Vineyard was established in the spring of 
1906, on the property of Mr. Louis Cortopassi, in the Sierra Nevada, 
2,412 feet above sea level, 1| miles southwest of Colfax, Placer Co., 
Cal. (See PL II, fig. 3.) 
