The U.S. Department of Agriculture on Wednesday lowered its estimate of the 2012-2013 Florida orange crop by one million boxes to 138 million boxes.The Valencia variety accounted for the decline going from 72 million boxes in March to 71 million this month. Early-mid varieties remained at 67 million boxes.The USDA makes its initial estimate in October of each year and revises it monthly as the crop takes shape until the end of the season in July. The USDA’s October orange estimate was 154 million boxes. During the 2011-2012 season, Florida produced 146.6 million boxes of oranges.“This is not unexpected,” said Michael W. Sparks, executive VP/CEO of Florida Citrus Mutual. “We have experienced unprecedented fruit drop as a result of dry weather and severe disease challenges from HLB, or citrus greening. Those factors have contributed to the current situation.”The 2012-2013 Florida grapefruit estimate held at 17 million boxes. Tangerines decreased to 3.5 million boxes while tangelos stayed at 1 million boxes. The yield for from concentrate orange juice remained at 1.61 gallons per 90-pound box.The Florida citrus industry creates a $9 billion annual economic impact, employing nearly 76,000 people, and covering about 550,000 acres.