Growers in southern California have been working quickly this week to repair irrigation systems damaged by last week’s wildfires, which hit avocado and citrus crops.

With a return of warm Santa Ana winds predicted before the weekend, meteorologists forecast that producers will need to provide more water to their crops.

This is especially true in avocado orchards where trees were damaged by fire but may still be salvageable.

"The growers need to get water onto their trees," said Guy Witney, director of industry affairs for the California Avocado Commission. "We've got crews working all over the industry trying to repair irrigation systems.”

The commission estimates that producers lost 10 percent of this year's avocado production to last week's windstorms and wildfires. Crop losses have been estimated at $35 million but it is still too early to estimate the value of the avocado trees killed by fire. The 10 percent loss comes from what had been predicted as an above average 2007-08 crop.

The knock-on effect on the global avocado supply situation is that Mexico is likely to fill a lot of the gap and even despite the losses, the commission still forecasts that California could still produce an average-sized avocado crop this season. Any other shortfall could be made up by Chile or potentially even New Zealand, according to the California Farm Bureau.

San Diego County - the worst affected by the blazes - has begun estimating agricultural losses from its numerous wildfires. In the Rice Canyon fire, the most severe agricultural losses affected ornamental nursery plants, cut flowers and avocados. Other crops damaged included persimmons, lemons and macadamia nuts.