Guayule Rubber Industry in Salinas, California, ca. 1942
Processed by Katherine Ruiz.
The Bancroft Library, University of California, Berkeley
Berkeley, California 94720-6000
Guayule Rubber Industry in Salinas, California, ca. 1942
BANC PIC 1962.006--fALB
The Bancroft Library
University of California
Finding aid and digital representations of archival materials funded in part by a grant from the National Endowment for the
- Processed and encoded by:
- California Heritage Digital Image Access Project staff in The Bancroft Library and The Library's Electronic Text Unit
- Digital images processed by:
- The Library Photographic Service
- Finding aid completed:
- November 1996
© 1997 The Regents of the University of California
Collection Title: Guayule Rubber Industry in Salinas, California
Collection Number: BANC PIC 1962.006--fALB
1 album (44 photographic prints) ; 17 x 34 cm. ; ephemera
44 digital objects
The Bancroft Library. University of California, Berkeley.
Berkeley, California 94720-6000
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[Identification of item],
Guayule Rubber Industry in Salinas, California, BANC PIC 1962.006--fALB, The Bancroft Library, University of California, Berkeley.
Digital Representations Available
Identifier/Call Number: BANC MSS C-B 834:
Title: Sheridan Downey Papers
Identifier/Call Number: BANC PIC 1981.076--PIC:
Title: California Park and Recreation Areas, and Other Western Views, ca. 1930-ca. 1949
Transferred from the Sheridan Downey papers (BANC MSS C-B 834).
Extraction of rubber from guayule plants escalated in the United States as a consequence of the Second World War. During World
War II, Americans found themselves lacking in rubber supplies, as Japan controlled 90% of the world's rubber supply and American-made
synthetic rubber proved inferior to the natural product. As early as 1907, experiments by the Intercontinental Rubber Company
were conducted on guayule, a Mexican desert shrub which contained 20% pure rubber that lent itself to harvesting. The International
Rubber Company soon began to breed the plant to produce double that amount of rubber. After harvesting, the plant was sent
to a mill for production, where it was compressed into molds for shipment.
The Salinas Valley was host to commercial operations on a large scale, begun in 1926 by the Intercontinental Rubber Company.
Eight thousand acres of guayule were under cultivation and up to five tons of guayule rubber were turned out daily. After
a paper published by Intercontinental Rubber's vice president, Dr. David Spence, outlined how the United States could not
become dependent on foreign supplies, the War Department sent two majors (one of whom was Dwight D. Eisenhower) to investigate
the Salinas operation. After the outbreak of hostilities with Japan, the federal government passed the Emergency Rubber Project
Act in 1942 and took over Intercontinental's operations in Salinas, creating the Guayule Rubber Project, under the direction
of the United States Forest Service. Nurseries were established for the Salinas plant near Bakersfield, Oceanside, and Indio,
California and in New Mexico, Arizona, and Texas. By 1944, 32,000 acres were devoted to the growing of guayule.
The end of World War II and the improvement of synthetic rubber meant the end of the guayule project in the Salinas Valley.
After 1945 the Salinas land was turned over to the production of other crops.
(Source: Verardo, Jennie Dennis, and Denzil Verardo.
The Salinas Valley : an Illustrated History. Northridge, CA: Windsor Publications, 1989.)
Scope and Content
This collection consists of an album of 44 photographic prints, plus ephemera, of the guayule rubber industry in Salinas,
California, circa 1942. The photographer is unknown. Included in the photographs are images of workers planting, harvesting
and manufacturing the guayule; views of agricultural equipment; guayule fields; guayule plants; mills and mill machinery at
Salinas; and Senator Sheridan Downey, Major Evan W. Kelley of the U.S. Forest Service, rubber chemist Dr. David Spence, and
members of the "Truman Committee," which investigated Salinas' guayule industry.
The ephemera consists of three items: a letter from the Salinas Chamber of Commerce to Senator Sheridan Downey, sheets of
information on guayule rubber, and another letter from the Salinas Chamber of Commerce to the Truman Committee of the Senate.
The first letter is one page, to Senator Sheridan Downey from Fred S. McCargar of the Salinas Chamber of Commerce, introducing
the album as a scrapbook of the development of the guayule project in Salinas. Following it are five sheets of information,
in the form of questions and answers, about the planting, harvesting, and production of rubber from the guayule plant. The
last segment is a four-page letter, again from McCargar, to the Truman Committee of the Senate, outlining the production of
guayule rubber before and after the government took control of the Salinas operations on March 5, 1942.
This collection was put together with the cooperation of the Salinas Chamber of Commerce, the United States Forest Service,
and the Intercontinental Rubber Company. Typewritten captions are pasted below the photographs, and are reprinted in the container
Preparing the seed beds in the nursery. The ground must be finely pulverized. Note the duckboards and the overhead watering
New Seed sower. Plants seed in two inch strips with five inch space between. Seed hopper in front, and hopper in the rear.
One of the first seed planters, which broadcast the seed on the ground and covered it with sand.
[Machine working the field]
Nursery seedlings, eight months old, ready for digging and transplanting to the fields.
Topping seedlings prior to digging for transplanting to the fields. Group of General Tire Company officials and wives watching
Closeup view of seedling topper.
Another original machine, which Bud Spencer is driving, loosens the dirt around the nursery plants when they have been topped.
The roots go straight down for eight to twelve inches and this operation makes it simple for the laborers to gather them,
one of the few hand processes in the growth of guayule. Dr. David H. Spence, Stanford University rubber chemist, maintains
that the cheapest way to grow guayule is to harvest the plants when they are at this stage. William O'Neil, General Tire's
president, believes this system should be adopted for emergency development of a rubber supply.
Laborers picking seedlings from the beds after digging same.
One year old seedling, showing hundreds of flowers. Each flower produces five seeds. Estimated production for a mature plant
is between two and five thousand seeds per year. Present seed collecting device, to date, has only collected about ten seeds
per plant. Therefore, this device needs perfecting.
Six row seed planter. Each man plants about 50 plants per minute planting them in rows thirty-six inches apart and twenty-eight
inches apart in the rows. An electric device on a corn planter check wire makes it possible to cross-cultivate both ways.
Seed planter starting operations on March 5, 1942, the day the President signed the Guayule Rubber Bill. Executives of the
General Tire Company acting as the laborers.
Planting operations starting March 5, 1942 by the Forest Service. Have planted 70 acres to date, March 16, 1943.
Cross-cultivation is a simple process with this machine.
Mature seven year old field. This field went 2,850 pounds of rubber per acre in 1941.
From this plant which Juan holds can be extracted a quantity of real rubber equal to 23 per cent of the weight of the plant.
The rubber comes from the roots and branches, only the leaves having no rubber content. This plant is seven years old. At
this age it reaches its peak in rubber content.
Plow which plows two rows, including the roots, piling them all into one row.
Harvesting device which picks up the two plowed rows of guayule rubber, choppes [sic] it up in a sileage cutting device, and
elevates it into wagons to be hauled to the mill.
Harvesting device which picks up the two plowed rows of guayule rubber, chops it up in a sileage cutting device, and elevates
it into wagons to be hauled to the mill.
Four year old plant. Note yard stick.
Seed picking device. Knocks the seed off and collects it in receptacle in the rear by vacuum. (Seed is collected from two
Another seed collecting device that was first developed collected the seed from one row. Apparently these machines are rather
inefficient as they have only been able to collect ten seeds per plant, while it is estimated each plant can produce from
two to five thousand seeds per year.
After the seed is dried, it is placed in air tight drums where it keeps almost indefinitely.
Mill at Salinas, California which cost $265,000.
Chopped shrub at the bin where it has been dumped from the wagons from the fields. Shrubs go through three sets of rollers
before going into the mill proper.
Another picture of the mill.
The first settling tank. The wood silt becomes water logged and goes to the bottom. The rubber floats, together with some
cork, the latter being removed by forcing water into the air cells of the cork under 350 pounds pressure, which sinks in the
settling tank. This picture is out of order, and should be in following the next two.
Long tubular ball mills are used, using flint stones the size of the fist which come from Norway or Belgium, because of their
These giant crushers are filled with rocks. Chopped guayule is put in these tanks and rotated so that the rocks crush the
wood pulp, and separate it from the rubber.
These stones, imported from Norway, are used as a primary part of the milling process. Search is now being made in America
for stones having similar qualities of hardness.
The pulp from the crushers is then transferred to these water filled vats. The wood pulp sinks to the bottom and the rubber
and cork rises to the top and is skimmed off.
Rubber being scraped from the trays after drying.
Wet rubber being placed in the trays prior to drying.
Sheet of dried rubber before it is pressed in a box.
Rubber press which presses the rubber into blocks of 100 pounds each - two blocks to a box. This rubber contains about 18
or 20 percent resin and other impurities. One of the problems is the elimination of this resin and particularly, the elimination
of the impurities. Dr. D. Spence is working on a plan of purification of guayule rubber.
Dr. D. Spence, well known rubber chemist and specialist, Major Evan W. Kelley of the United States Forest Service in charge
of the Government project and Senator Sheridan Downey.
Major Kelley, Senator Downey and Dr. D. Spence. Dr. Spence advocates the planting of the seed thick in the spring and harvesting
in the fall, and states that his experiments show that he could get 1170 pounds of pure rubber per acre, which he maintains
can be produced at a great deal less cost, and a great deal quicker, than under the transplanting plan.
The Truman Committee in Salinas investigation [sic] guayule rubber, being beseiged [sic] by the mothers of 186 Salinas boys
with General McArthur, requesting that something be done to help their boys. Left to right, Senator Kilgore, West Virginia,
Senator Ball, Minnesota and Senator Downey, California.
Senator Kilgore, West Virginia, Senator Ball, Minnesota and Senator Walldren, Washington at the guayule rubber mill at Salinas,
California where they carried on an extensive investigation and hearing of guayule rubber on March 15, 1942.
Almost a thousand miles of duckboards and wooden rails on which to run the machinery at the new nurseries being built at Salinas.
Contract for this job was $283,000.
The site of the 1,000 head labor camp. Contract, $183,000.