Freezing temperatures in December had a negative affect on California's citrus crop, wiping out a quarter of the state's navel and mandarin oranges and lemons according to California Citrus Mutual. The loss is estimated at $441 million to the $2 billion California citrus market, and industry watchers predict this year's drought could affect next year's crop as well. However, growth in the mandarin category provides some good news. According to Nielson Perishables Group, the category grew by 12 percent season-to-date through December 28.