The Diseases of Florida Navel Oranges

Navel oranges are treasured as one of the sweetest kinds of oranges. However, diseases of Florida navel oranges wreak havoc on orange groves each year, including one that could kill the entire spices within a decade.

Citrus Canker

Citrus cankers disease causes the leaf and fruit to fall too soon. It is a contagious bacterial condition. Symptoms include lesions and brown coloring on the fruit and leaves.

Greening

Greening disease causes oranges to become bitter, small and green in color. Orange trees with this disease are uprooted and destroyed because there is no cure. According to the U.S. Department of Agriculture, this disease could possibly wipe out Florida navel oranges in 10 years.

Citrus Scab

Citrus Scab causes wart-like growths on the fruit, leaves and twigs. These growths are aggressive and spread quickly. Treatment consists of avoiding overhead watering of the trees and applying copper sprays to infected trees.

Rust Mite

Rust mites are small insects that feed on the navel oranges causing a rusting or dull brown appearance to the fruit. Rust mites do not like the sun, so fruit damage is rarely on the side of the fruit facing the sun. The worst mite infections cause leaf drop.

Foot Rot

Foot Rot is a disease that affects the orange tree wood. The tree bark oozes a gummy substance or water before the bark peels off. The fungal spores that cause foot rot splash from the soil to the tree during rain. Pruning lower branches help in keeping foot rot away from the tree.

Resources

• Florida Citrus Organizations
• University of Florida Citrus Research and Education Center
• EDIS Florida Dooryard Citrus Guide