Smudge Pots

Fruit growers will sometimes use smudge pots to try to protect their crops from a possible killing frost, particularly on clear, cold nights. A smudge pot is a portable heater/burner which produces thick heavy smoke. Fruit growers place a number of these around the orchard in the evening to prevent the crop from freezing at night. Do smudge pots actually work? Why?

• A. Yes. They work simply by heating the air in the orchard to keep it above freezing.
• B. No. They don't work. They can not supply enough heat to keep the orchard from freezing.
• C. Yes. They work by producing a heavy smoke layer over the orchard which prevents heat loss by radiation to the night sky
• D. I think someone should notify the Pollution Control Agency.

See if you picked correctly.

Answer

Smudge Pots - Answer = C

The smudge pots do not put out enough heat to heat the orchard, however the thick smoke cloud acts to reflect infrared radiation (heat radiation) from the orchard, thus "trapping" heat between the cloud and the ground. By reducing the amount of heat lost by radiation to the night sky, the orchard cools more slowly, hopefully keeping it above the freezing point through the night.

Return to the question.