U.S. spot prices for propane, a petroleum product used for home heating, chemical production, crop drying and outdoor cooking, dropped sharply in recent weeks, signaling the end of seasonal buying during a particularly long and harsh winter, according to PetroChem Wire.

Spot propane, which sold in mid-February for close to $1.60 per gallon, sold for $1.09 per gallon on March 7, a level not seen since early last October, according to the daily newsletter. The mid-February price was significantly higher than the price peak reached the previous winter when spot propane typically traded on the Gulf Coast under $1 per gallon.

Propane prices were high in recent months due to the unusually cold weather throughout much of the U.S. and increased demand for propane for crop drying. The agricultural industry uses propane to power various farm equipment. That includes propane-powered drying systems that help farmers meet crop moisture content specifications needed to prevent rotting in storage and, therefore, get better prices for their harvest.

"The late harvest this year due to heavy rains created competition with pre-winter buying from retailers," said Pat Whalen, managing editor of PetroChem Wire.