During the winter of 1949-1950, freezing weather gripped the Southland's citrus industry for the third year in a row, prompting growers to fire up millions of smoky orchard heaters that filled the air -- and lungs -- with black smoke.
"You'd blow your nose, and it would be black," said Edward Camarena, a former chemist with the Orange County Air Pollution Control District, the first air quality agency to regulate orchard heaters, popularly known as smudge pots. Wintertime atmospheric inversions also trapped the thick smoke close to the ground.
"I can remember getting up and going to work and seeing this ugly black haze where they had smudged most of the night," said Jack Adame, a retired University of California, Riverside employee and now the volunteer master gardener for the University of California Cooperative Extension -Riverside County.
Following World War II, air pollution captured the public's attention, and orchard heaters, like smoking diesel trucks and open burning at garbage dumps, were a significant and visible source of smog.
-- From the Pasadena Star-News, Oct. 20, 1947
In the fall of 1947, Louis C. McCabe, director of the newly formed Los Angeles Air Pollution Control District, appealed to Southland citrus growers to eliminate smoke from more than 4 million orchard heaters.
"There was a belief that smoke helped hold the heat in, and therefore, smoke was good," Camarena said.
McCabe and agricultural authorities launched a campaign to educate growers on how to operate heaters so they prevented frost damage to crops, but didn't belch out black clouds.
In 1950, the Orange County Air Pollution Control District adopted a regulation prohibiting the use of dirty fuels, including old tires and used motor oil, in smudge pots. They also banned the smokiest smudge pots, which included garbage pails.
Seven other air pollution control districts and the state Air Resources Board subsequently adopted similar rules. Other factors contributed to the demise of the smudge pot.
1950s brochure advising growers on the use of smudge pots
During the early 1950s, growers started using wind machines in place of smudge pots. A large propeller mounted on a tower mixed pockets of cool and warm air in orchards, effectively raising temperatures at the ground and preventing frost damage. The wind machines were more expensive to buy, but cost-effective over a period of years because they didn't have to be constantly tended, as smudge pots did, by a small army of laborers.
Orchard heaters fell out of use completely by the 1970s, Adame said. In addition, almost all commercial citrus growing has moved out of the area to the state's Central Valley, he said.
Today, residents might still see the rusted hulk of a smudge pot lying in an orange grove, serving as a reminder of a bygone era and a polluting nuisance put in its place by clean technology.
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