Modeling an orange grove (Part 4)

The weather forecast announces frost for the night. Time to inspect the orchard heaters and fill them up with oil. The smudge pots were developed after a disastrous freeze in Southern California in January 1913 wiped out a whole crop.

When the air temperature reaches 29°F (-2°C) the pots are ignited. For each additional degree of drop, another hole is opened on the control cap. Below 25°F there's nothing more that can be done to enhance the heating effects.

The citrus growers needed a lot of workers to keep the pots burning.

Photo from a brochure

 

A smudge pot or orchard heater is an oil-burning device used to prevent frost on fruit trees. Usually it has a large round base with a chimney coming out of the middle of the base. The smudge pot is placed between trees in an orchard. The burning oil creates some heat, but more importantly, a large amount of smoke, particulates, carbon dioxide and water vapor. This artificial smog forms a blanket that blocks infrared light, thereby preventing radiative cooling that would otherwise caus or worsen frost. (Low clouds can have a similar "infrared blanket" effect, which is why cloudy nights tend to be warmer than clear-sky nights. (Source Wikipedia)

Century Foundry Metal Works (www.showcaseminiatures.com) sells HO scale smudge pots. I painted the white metal castings aluminum with some black on the chimney and also added some Rust-All. Then I placed them between the rows of orange trees.

This smudge pot has been recently lit off, as the exhaust on a fully hot pot becomes almost invisible with a mere hint of red/orange flame. Note that the filler/flue cap is in the fully open position (all holes open) (Source: Wikipedia)

In this picture from the Library of Congress we see a view of smudge pots in an orange grove on Victoria Avenue in Arlington Heights, Riverside, California. Following WWII, air pollution captured the public's attention and orchard heaters, like smoking diesel trucks and open burning at garbage dumps, were a signigicant and visible source of smod. 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.

During the 1950s, growers started using wind machines in place of smudge pots. But orchard heaters only fell out of use completely by the 1970's (!!)

The ground between the rows of citrus trees  was regularly plowed and disked to smooth the earth. Weeds were controlled by chemicals like weedoil and others.

Stay tuned for more on modeling an orange grove