Mandarins hit hardest by cold temperatures

Mandarins suffered the worst damage from the more than four weeks of below freezing temperatures that struck the citrus belt this winter.

California Citrus Mutual (CCM) estimated Wednesday that approximately 20% of this season’s mandarin crop will be lost to frost damage.

Mandarins is about a $100 million a year crop in Tulare County.

The general consensus across the industry is positive in respect to fruit quality considering the obstacles growers were faced with this season.

However, the more than 25 days of temperatures dipping at or below freezing cost growers millions of dollars. The number of freeze nights was a record.

Temperatures many times dipped below 26 degrees, but conditions were good enough that many growers were able to raise those temperatures 3 to 4 degrees, above safe levels.

Temperatures below 28 degrees for more than four hours can cause serious damage.

Growers have spent on average $300-$400 per acre on frost protection, totaling approximately $100 million to preserve the 2011-2012 crop and ensure only quality fruit reaches the consumer, stated Citrus Mutual in a press release.

Frost protection was utilized in December and January in order to raise grove temperatures to 32 degrees, the threshold for mandarin varieties.

CCM President, Joel Nelsen, has communicated to the CDFA and county agricultural commissioners to be on high alert for freeze damaged fruit during inspections of the mandarin crops, stating that “it is imperative that freeze damaged fruit not find its way to consumer.”

Damage to the navel crop was significantly less with an estimated 10% of the crop damaged. Navel oranges have a much higher tolerance of cold temperatures, with a threshold of 27 degrees versus 32 degrees for mandarin varieties.

Generally, cold temperatures have helped to improve color and rind quality of the navels resulting in a fresh, quality product remaining on the tree. A lack of rain, however, has slowed average fruit growth with approximately 70% of navels left to be harvested.

The 2011-2012 navel crop is now anticipated to be smaller in respect to the total number of cartons produced than originally expected.