Florida navel oranges are sweet and delicious, considered "King of Oranges" by citrus groves like Hale Groves in the area. However, a variety of diseases can attack these delicious fruits and render them inedible or severely stunt crop yield. The best way to deal with this threat is be to aware of the signs and symptoms of these infections so that you can take fast, effective action should you spot indications of trouble.
According to a history compiled at Purdue University, a 1984 citrus canker infection necessitated the burning of thousands of Florida orange trees. This infection causes lesions and corky cankers to form on the leaves, stems and fruits of Florida navel orange trees. It can eventually kill the tree after it causes all the leaves and fruit to drop from the tree and become inedible. Citrus canker was believed to be eradicated in Florida at that time, but researchers anticipate reintroduction and the state has already had several related forms of infection in the intervening years.
Citrus greening is a highly destructive bacterial infection that is spread by the Asian citrus psyllid, a small insect. The disease causes blotchy, yellow leaves, stunted growth, shoot death, abnormally small fruits in abnormally small quantities and fruits that taste "off" in flavor. There is currently no cure for citrus greening, reports Science Daily, but by removing infected trees and treating orchards with preventative pesticides, most farmers are able to control the problem or even eliminate it from their fields over time.
Post-Harvest Rot, Mold and Mildew
While you might think that your problems with diseases of Florida navel oranges are over once they are off the tree and in the crate, you would be mistaken. Florida navel orange harvests are constantly threatened by rot, mold and mildew infections caused by improper storage conditions. These infections lead to soft, discolored and inedible fruit. Damaged fruits should not be stored with other fruit since they are more prone to developing these issues. Post-harvest fungicides can also be used to prevent infections. Try to keep the stored fruit in an area that is not too humid and that can be kept dry to prevent infections.