"We've had some really big blows," said Wayne Brydon, field service manager of the California Avocado Commission, the San Diego Union-Tribune reported Monday.

San Diego County wildfires in 2007, water restrictions that took effect in 2008 and an early heat wave last spring have combined to drop the crop estimate to 210 million pounds, close to the 1990 yield of 207 million pounds, the commission reported.

Consumers may not see much difference in price and Chile is the source of most avocados during the Super Bowl, the report said. But, California growers are expected to see earnings drop to $220.5 million, down from $327 million a year ago.

Farmers said the heat wave was the biggest blow to this year's crop.

Fallbrook, Calif., avocado grower Charley Wolk said the heat knocked the flowers off trees before they could set fruit.

"In May, I couldn't find any fruit on my trees," he said. "My neck hurt from walking up and down the groves looking for fruit."